PROTECTION AUDIT REPORT

General Information:
Substation Name: 220 KV SS RAMAGIRI
SS Voltage level: 220/33 KV

3 ph
Voltage
fault 1 ph fault MVA
level
Fault level of all MVA
Equipment
(for both 3-ph & 1-ph
faults at all voltage
levels)
220 kV
Bus

Date of commissioning
of the substation:
Region: Southern Region
Checking and Validation
08.01.2025
Date Date:
Name of the Utility which
APTRANSCO
owns the Substation

Audit Team:
Name Organization Name

Auditee Team:
Name Organization Name
A.V.GIRIDHAR APTRANSCO
K. VEERANARAYANA
APTRANSCO
REDDY
N. NAGARAJU APTRANSCO

Attached Documents:
1 Detailed Single Line Diagram of the Substation

2 Protection Philosophy being followed

3 Adopted Relay Settings (given by Head Quarters/ Corporate Office)

4 Extracted Relay Settings (in PDF format)

Southern Region - (Station Name) 1/58

 5 Calculation Sheet(s) showing protection settings calculation for all feeders and transformers

6 AC Supply Changeover Scheme

7 Details on Periodicity of Relay Testing and latest Relay Test Reports

8 Details of Measurement of Dependability & Security of PLCC Channels

9 CT Characteristics at all Taps in case of multi-ratio CTs

10 Details of Measurement of Station Earth-Mat & Earth-Pits
11 Details & Settings of df/dt and UF Relays, if applicable
Details of Special Protection Schemes details, if applicable (including implemented
12
schematic diagram for SPS, test results, last operation records)
13 Record of previous tripping’s (in last one year) and details of protection operation

14 Sample DR's of various Protection Relays

Block diagram of the transfer function of the Governor model implemented. Mention the
15 Gains and time constant implemented in the model (for all Units in case of generating
station)

Block diagram of the transfer function of the AVR model implemented. Mention the Gains
16
and time constant implemented in the model (for all Units in case of generating station)

Block diagram of transfer function of Power System Stabilizer (PSS) model implemented.
17 Mention the Gains and time constant implemented in the model (for all Units in case of
generating station)

18 DC Aux SLD

19 SAS architecture diagram

Verification of existing settings at

20
substation in line with the PSSG Recommendations/ SR Protection protocol
21 Chronic reason of tripping, if any
22 Status of Recommendation of previous third party protection audit

AUDITEE TEAM AUDIT TEAM

Southern Region - (Station Name) 2/58

 (Capacity) MW Generator Unit-1 Protection Audit - check list
Audited data
No Relay configuration - Generator protections
1 Name, voltage, power
2 Are used 2 groups of protections (Group A and Group B) for Gen. Unit protection? Yes /No
3 Are Group A and Group B protections connected to separate DC sources for Gen. Unit? Yes /No
4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Differential protection Yes /No

100% Stator Earth Fault protection Yes /No

95% Stator Earth Fault protection Yes /No

Inter-turn Fault protection Yes /No

Loss of Excitation protection Yes /No

5
Negative Phase Sequence Current protection Yes /No

Low Forward Power/ Reverse Power protection Yes /No

Out-of-step/ Pole slipping protection Yes /No

Over-Voltage protection Yes /No

Under-frequency protection Yes /No

Back-up Impedance protection Yes /No

Accidental back-energisation/ Dead machine protection Yes /No

Rotor Earth-Fault protection Yes /No

Thermal Over-load protection Yes /No

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to Trip Coil 1/Trip Coil2/Both
6
Feed from DC supply 1/DC supply2
7
Connected to dedicated CT core?
8
Define CT core no. to which the relay is connected

Southern Region - (Station Name) 3/58

 (Capacity) MW Generator Unit-1 Protection Audit - check list
Audited data
No Relay configuration - Generator protections
CT ratio selected
9

10 VT ratio selected

Details of separate relays if applicable Yes/No

Relay 1 make and model

Functions available in Relay 1

Relay 1 Functional Yes/ No
Date of Testing

Relay 2 make and model

11
Functions available in Relay 1
Relay 2 Functional Yes/ No
Date of Testing

Relay 3 make and model

Functions available in Relay 1

Relay 3 Functional Yes/ No
Date of Testing
Are all the Lock out relays (86) considered for Gen. Unit protection provided with supervision relays
12 Yes/No
(74/86) ?

Do the Gen. Unit protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
13 Yes/No
74/DC-2)?

Southern Region - (Station Name) 4/58

 (Capacity) MW Generator Unit-2 Protection Audit - check list
Audited data
No Relay configuration - Generator protections
1 Name, voltage, power
2 Are used 2 groups of protections (Group A and Group B) for Gen. Unit protection? Yes /No
3 Are Group A and Group B protections connected to separate DC sources for Gen. Unit? Yes /No
4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Differential protection Yes /No

100% Stator Earth Fault protection Yes /No

95% Stator Earth Fault protection Yes /No

Inter-turn Fault protection Yes /No

Loss of Excitation protection Yes /No

5
Negative Phase Sequence Current protection Yes /No

Low Forward Power/ Reverse Power protection Yes /No

Out-of-step/ Pole slipping protection Yes /No

Over-Voltage protection Yes /No

Under-frequency protection Yes /No

Back-up Impedance protection Yes /No

Accidental back-energisation/ Dead machine protection Yes /No

Rotor Earth-Fault protection Yes /No

Thermal Over-load protection Yes /No

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to Trip Coil 1/Trip Coil2/Both
6
Feed from DC supply 1/DC supply2
7
Connected to dedicated CT core?
8
Define CT core no. to which the relay is connected

Southern Region - (Station Name) 5/58

 (Capacity) MW Generator Unit-2 Protection Audit - check list
Audited data
No Relay configuration - Generator protections
CT ratio selected
9

10 VT ratio selected

Details of separate relays if applicable Yes/No

Relay 1 make and model

Functions available in Relay 1

Relay 1 Functional Yes/ No
Date of Testing

Relay 2 make and model

11
Functions available in Relay 1
Relay 2 Functional Yes/ No
Date of Testing

Relay 3 make and model

Functions available in Relay 1

Relay 3 Functional Yes/ No
Date of Testing
Are all the Lock out relays (86) considered for Gen. Unit protection provided with supervision relays
12 Yes/No
(74/86) ?

Do the Gen. Unit protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
13 Yes/No
74/DC-2)?

Southern Region - (Station Name) 6/58

 (Capacity) MVA, HV/ LV kV GT-1 Generator Transformer Protection Audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power
2 Are used 2 groups of protections (Group A and Group B) for Gen. Transformer protection? Yes /No
3 Are Group A and Group B protections connected to separate DC sources for Gen. Transformer? Yes /No
4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Overall differential Yes /No

Differential protection Yes /No

REF protection
Yes /No
5
Back-up directional O/C +E/F protection Yes /No

Overfluxing protection Yes /No

Connected to Trip Coil 1/Trip Coil2/Both
Yes /No

Feed from DC supply 1/DC supply2 Yes /No

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to dedicated CT core?
Define CT core no. to which the relay is connected
CT ratio selected

Is CT supervision enabled or not in case of Gen. Transformer differential protection ?

Are all the Lock out relays (86) considered for Gen. Transformer protection provided with supervision
6 Yes/No
relays (74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No
74/DC-2)?
OTI working
8 Yes /No
OTI working
9 Yes /No

10 Buchholtz working Yes/No

11 PRD/ PRV working Yes/No

12 LA rating HV side Yes/No

13 LA rating IV side Yes/No

Southern Region - (Station Name) 7/58

 (Capacity) MVA, HV/ LV kV GT-2 Generator Transformer Protection Audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power
2 Are used 2 groups of protections (Group A and Group B) for Gen. Transformer protection? Yes /No
3 Are Group A and Group B protections connected to separate DC sources for Gen. Transformer? Yes /No
4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Overall differential Yes /No

Differential protection Yes /No

REF protection
Yes /No
5
Back-up directional O/C +E/F protection Yes /No

Overfluxing protection Yes /No

Connected to Trip Coil 1/Trip Coil2/Both
Yes /No

Feed from DC supply 1/DC supply2 Yes /No

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to dedicated CT core?
Define CT core no. to which the relay is connected
CT ratio selected

Is CT supervision enabled or not in case of Gen. Transformer differential protection ?

Are all the Lock out relays (86) considered for Gen. Transformer protection provided with supervision
6 Yes/No
relays (74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No
74/DC-2)?
OTI working
8 Yes /No
OTI working
9 Yes /No

10 Buchholtz working Yes/No

11 PRD/ PRV working Yes/No

12 LA rating HV side Yes/No

13 LA rating IV side Yes/No

Southern Region - (Station Name) 8/58

 765 kV (Line Name) Line-1 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line
2 Series compensated? Y/N
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)?
4 Which mode of communication is used (PLCC/ OPGW)

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522
Whether the relay is functional?? Yes/ No
Date of testing
Mention all the active protections 21/87L/67/67N/51/51N/59
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication)
Power swing/out of step active? Yes/No
SOTF active? Yes/No
Auto Reclose (79) active? Yes/No
Breaker failure active Yes/ No
Load Encroachment active Yes/ No
Stub Protection active Yes/ No
Fault locator active?
Yes/No
Disturbance Recorder active? Yes/No
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both?
7 Feed from DC supply 1 / DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected
9 CT ratio selected
10 VT ratio selected

Southern Region - (Station Name) 9/58

 765 kV (Line Name) Line-1 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation?
Overvoltage protection available Yes/ No
13 Functional with two stage protection
Yes/No
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 10/58

 765 kV (Line Name) Line-2 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line
2 Series compensated? Y/N
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)?
4 Which mode of communication is used (PLCC/ OPGW)

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522
Whether the relay is functional?? Yes/ No
Date of testing
Mention all the active protections 21/87L/67/67N/51/51N/59
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication)
Power swing/out of step active? Yes/No
SOTF active? Yes/No
Auto Reclose (79) active? Yes/No
Breaker failure active Yes/ No
Load Encroachment active Yes/ No
Stub Protection active Yes/ No
Fault locator active?
Yes/No
Disturbance Recorder active? Yes/No
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both?
7 Feed from DC supply 1 / DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected
9 CT ratio selected
10 VT ratio selected

Southern Region - (Station Name) 11/58

 765 kV (Line Name) Line-2 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation?
Overvoltage protection available Yes/ No
13 Functional with two stage protection
Yes/No
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 12/58

 765 kV (Line Name) Line-3 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line
2 Series compensated? Y/N
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)?
4 Which mode of communication is used (PLCC/ OPGW)

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522
Whether the relay is functional?? Yes/ No
Date of testing
Mention all the active protections 21/87L/67/67N/51/51N/59
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication)
Power swing/out of step active? Yes/No
SOTF active? Yes/No
Auto Reclose (79) active? Yes/No
Breaker failure active Yes/ No
Load Encroachment active Yes/ No
Stub Protection active Yes/ No
Fault locator active?
Yes/No
Disturbance Recorder active? Yes/No
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both?
7 Feed from DC supply 1 / DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected
9 CT ratio selected
10 VT ratio selected

Southern Region - (Station Name) 13/58

 765 kV (Line Name) Line-3 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation?
Overvoltage protection available Yes/ No
13 Functional with two stage protection
Yes/No
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 14/58

 765 kV (Line Name) Line-4 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line
2 Series compensated? Y/N
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)?
4 Which mode of communication is used (PLCC/ OPGW)

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522
Whether the relay is functional?? Yes/ No
Date of testing
Mention all the active protections 21/87L/67/67N/51/51N/59
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication)
Power swing/out of step active? Yes/No
SOTF active? Yes/No
Auto Reclose (79) active? Yes/No
Breaker failure active Yes/ No
Load Encroachment active Yes/ No
Stub Protection active Yes/ No
Fault locator active?
Yes/No
Disturbance Recorder active? Yes/No
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both?
7 Feed from DC supply 1 / DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected
9 CT ratio selected
10 VT ratio selected

Southern Region - (Station Name) 15/58

 765 kV (Line Name) Line-4 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation?
Overvoltage protection available Yes/ No
13 Functional with two stage protection
Yes/No
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 16/58

 400 kV (Line Name) Line-1 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line
2 Series compensated? Y/N
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)?
4 Which mode of communication is used (PLCC/ OPGW)

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522
Whether the relay is functional?? Yes/ No
Date of testing
Mention all the active protections 21/87L/67/67N/51/51N/59
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication)
Power swing/out of step active? Yes/No
SOTF active? Yes/No
Auto Reclose (79) active? Yes/No
Breaker failure active Yes/ No
Load Encroachment active Yes/ No
Stub Protection active Yes/ No
Fault locator active?
Yes/No
Disturbance Recorder active? Yes/No
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both?
7 Feed from DC supply 1 / DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected
9 CT ratio selected
10 VT ratio selected

Southern Region - (Station Name) 17/58

 400 kV (Line Name) Line-1 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation?
Overvoltage protection available Yes/ No
13 Functional with two stage protection
Yes/No
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 18/58

 400 kV (Line Name) Line-2 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line
2 Series compensated? Y/N
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)?
4 Which mode of communication is used (PLCC/ OPGW)

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522
Whether the relay is functional?? Yes/ No
Date of testing
Mention all the active protections 21/87L/67/67N/51/51N/59
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication)
Power swing/out of step active? Yes/No
SOTF active? Yes/No
Auto Reclose (79) active? Yes/No
Breaker failure active Yes/ No
Load Encroachment active Yes/ No
Stub Protection active Yes/ No
Fault locator active?
Yes/No
Disturbance Recorder active? Yes/No
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both?
7 Feed from DC supply 1 / DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected
9 CT ratio selected
10 VT ratio selected

Southern Region - (Station Name) 19/58

 400 kV (Line Name) Line-2 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation?
Overvoltage protection available Yes/ No
13 Functional with two stage protection
Yes/No
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 20/58

 400 kV (Line Name) Line-3 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line
2 Series compensated? Y/N
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)?
4 Which mode of communication is used (PLCC/ OPGW)

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522
Whether the relay is functional?? Yes/ No
Date of testing
Mention all the active protections 21/87L/67/67N/51/51N/59
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication)
Power swing/out of step active? Yes/No
SOTF active? Yes/No
Auto Reclose (79) active? Yes/No
Breaker failure active Yes/ No
Load Encroachment active Yes/ No
Stub Protection active Yes/ No
Fault locator active?
Yes/No
Disturbance Recorder active? Yes/No
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both?
7 Feed from DC supply 1 / DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected
9 CT ratio selected
10 VT ratio selected

Southern Region - (Station Name) 21/58

 400 kV (Line Name) Line-3 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation?
Overvoltage protection available Yes/ No
13 Functional with two stage protection
Yes/No
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 22/58

 400 kV (Line Name) Line-4 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line
2 Series compensated? Y/N
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)?
4 Which mode of communication is used (PLCC/ OPGW)

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522
Whether the relay is functional?? Yes/ No
Date of testing
Mention all the active protections 21/87L/67/67N/51/51N/59
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication)
Power swing/out of step active? Yes/No
SOTF active? Yes/No
Auto Reclose (79) active? Yes/No
Breaker failure active Yes/ No
Load Encroachment active Yes/ No
Stub Protection active Yes/ No
Fault locator active?
Yes/No
Disturbance Recorder active? Yes/No
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both?
7 Feed from DC supply 1 / DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected
9 CT ratio selected
10 VT ratio selected

Southern Region - (Station Name) 23/58

 400 kV (Line Name) Line-4 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation?
Overvoltage protection available Yes/ No
13 Functional with two stage protection
Yes/No
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 24/58

 220 kV Anantapur Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line 220 KV ANANTAPUR & 28.25 KM
2 Series compensated? Y/N NO
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)? LINE FEEDER
4 Which mode of communication is used (PLCC/ OPGW) OPGW

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522 GE D60 MICOM P444
Whether the relay is functional?? Yes/ No YES YES
Date of testing 31.12.24 31.12.24
Mention all the active protections 21/87L/67/67N/51/51N/59 21/67/67N/51/51N 21/67/67N/51/51N
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive Permissive Under reach Permissive Under reach
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)
5 Carrier aided scheme active for 67/67N Yes/ No YES YES
Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N NO NO
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication) NA NA
Power swing/out of step active? Yes/No YES YES
SOTF active? Yes/No YES YES
Auto Reclose (79) active? Yes/No YES YES
Breaker failure active Yes/ No NO NO
Load Encroachment active Yes/ No YES YES
Stub Protection active Yes/ No NO NO
Fault locator active?
Yes/No YES YES
Disturbance Recorder active? Yes/No YES YES
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both? Both Both
7 Feed from DC supply 1 / DC Supply 2 DC Supply 1 DC Supply 1
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected Core-1 Core-2
9 CT ratio selected 800/1 A 800/1 A
10 VT ratio selected 220 kV/110 V 220 kV/110 V

Southern Region - (220 KV SS Ramagiri) 25/58

 220 kV Anantapur Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
NA
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation? YES
Overvoltage protection available Yes/ No NO
13 Functional with two stage protection
Yes/No NO
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No NO
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No YES
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (220 KV SS Ramagiri) 26/58

 220 kV Shapuram Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line 220 KV SHAPURAM & 22.2 KM
2 Series compensated? Y/N NO
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)? LINE FEEDER
4 Which mode of communication is used (PLCC/ OPGW) OPGW

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522 Micom P444 ABB REL670
Whether the relay is functional?? Yes/ No YES YES
Date of testing 31.12.24 31.12.24
Mention all the active protections 21/87L/67/67N/51/51N/59 21/67/67N/51/51N 21/67/67N/51/51N
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive Permissive Under reach Permissive Under reach
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)
5 Carrier aided scheme active for 67/67N Yes/ No YES YES
Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N NO NO
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication) NA NA
Power swing/out of step active? Yes/No YES YES
SOTF active? Yes/No YES YES
Auto Reclose (79) active? Yes/No YES YES
Breaker failure active Yes/ No NO NO
Load Encroachment active Yes/ No YES YES
Stub Protection active Yes/ No NO NO
Fault locator active?
Yes/No YES YES
Disturbance Recorder active? Yes/No YES YES
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both? Both Both
7 Feed from DC supply 1 / DC Supply 2 DC Supply 1 DC Supply 1
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected Core-1 Core-2
9 CT ratio selected 800/1 A 800/1 A
10 VT ratio selected 220 kV/110 V 220 kV/110 V

Southern Region - (220 KV SS Ramagiri) 27/58

 220 kV Shapuram Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
NA
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation? YES
Overvoltage protection available Yes/ No NO
13 Functional with two stage protection
Yes/No NO
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No NO
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No YES
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (220 KV SS Ramagiri) 28/58

 220 kV Muttala-1 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line 220 KV MUTTALA-1 & 44.87 KM
2 Series compensated? Y/N NO
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)? LINE FEEDER
4 Which mode of communication is used (PLCC/ OPGW) PLCC

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522 ABB REL670 MICOM P444
Whether the relay is functional?? Yes/ No YES YES
Date of testing 13.12.2024 13.12.2024
Mention all the active protections 21/87L/67/67N/51/51N/59 21/67/67N/51/51N 21/67/67N/51/51N

Accelerated Under reach/

Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive Permissive Under reach Permissive Under reach
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

Carrier aided scheme active for 67/67N Yes/ No YES YES

5
Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N NO NO
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication) NA NA
Power swing/out of step active? Yes/No YES YES
SOTF active? Yes/No YES YES
Auto Reclose (79) active? Yes/No YES YES
Breaker failure active Yes/ No NO NO
Load Encroachment active Yes/ No YES YES
Stub Protection active Yes/ No NO NO
Fault locator active?
Yes/No YES YES
Disturbance Recorder active? Yes/No YES YES
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both? Both Both
7 Feed from DC supply 1 / DC Supply 2 DC Supply 1 DC Supply 1
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected Core-1 Core-2
9 CT ratio selected 800/1 A 800/1 A
10 VT ratio selected 220 kV/110 V 220 kV/110 V
 220 kV Muttala-1 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
NA
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation? YES
Overvoltage protection available Yes/ No NO
13 Functional with two stage protection
Yes/No NO
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No NO
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No YES
DC supply-2 (74/DC-1 & 74/DC-2)?
 220 KV Muttala-2 Distance Protection Audit -Check List
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line 220 KV MUTTALA-2 & 44.87 KM
2 Series compensated? Y/N NO
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)? LINE FEEDER
4 Which mode of communication is used (PLCC/ OPGW) PLCC

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522 ABB REL670 MICOM P444
Whether the relay is functional?? Yes/ No YES YES
Date of testing 13.12.2024 13.12.2024
Mention all the active protections 21/87L/67/67N/51/51N/59 21/67/67N/51/51N 21/67/67N/51/51N
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive Permissive Under reach Permissive Under reach
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)
Carrier aided scheme active for 67/67N Yes/ No YES YES
5
Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N NO NO
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication) NA NA
Power swing/out of step active? Yes/No YES YES
SOTF active? Yes/No YES YES
Auto Reclose (79) active? Yes/No YES YES
Breaker failure active Yes/ No NO NO
Load Encroachment active Yes/ No YES YES
Stub Protection active Yes/ No NO NO
Fault locator active?
Yes/No YES YES
Disturbance Recorder active? Yes/No YES YES
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both? Both Both
7 Feed from DC supply 1 / DC Supply 2 DC Supply 1 DC Supply 1
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected Core-1 Core-2
9 CT ratio selected 800/1 A 800/1 A
10 VT ratio selected 220 kV/110 V 220 kV/110 V
 220 KV Muttala-2 Distance Protection Audit -Check List
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
NA
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation? YES
Overvoltage protection available Yes/ No NO
13 Functional with two stage protection
Yes/No NO
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No NO
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No YES
DC supply-2 (74/DC-1 & 74/DC-2)?
 220 kV Thimmapuram-1 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line 220 KV THIMMAPURAM-1 & 56.8 KM
2 Series compensated? Y/N NO
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)? LINE FEEDER
4 Which mode of communication is used (PLCC/ OPGW) OPGW

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522 P444 REL670
Whether the relay is functional?? Yes/ No YES YES
Date of testing 18.09.2024 18.09.2024
Mention all the active protections 21/87L/67/67N/51/51N/59 21/67/67N/51/51N 21/67/67N/51/51N
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive Permissive Under reach Permissive Under reach
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No YES YES

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N NO NO
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication) NA NA
Power swing/out of step active? Yes/No YES YES
SOTF active? Yes/No YES YES
Auto Reclose (79) active? Yes/No YES YES
Breaker failure active Yes/ No NO NO
Load Encroachment active Yes/ No YES YES
Stub Protection active Yes/ No NO NO
Fault locator active?
Yes/No YES YES
Disturbance Recorder active? Yes/No YES YES
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both? Both Both
7 Feed from DC supply 1 / DC Supply 2 DC Supply 2 DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected Core-1 Core-2
9 CT ratio selected 800/1 A 800/1 A
10 VT ratio selected 220 kV/110 V 220 kV/110 V

Southern Region - (Station Name) 33/58

 220 kV Thimmapuram-1 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
NA
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation? YES
Overvoltage protection available Yes/ No NO
13 Functional with two stage protection
Yes/No NO
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No YES
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No YES
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 34/58

 220 kV Thimmapuram-2 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
1 Name and length of line 220 KV THIMMAPURAM-2 & 56.8 KM
2 Series compensated? Y/N NO
3 Is this a cable feeder / line feeder/ composite feeder (line+cable)? LINE FEEDER
4 Which mode of communication is used (PLCC/ OPGW) OPGW

Other Relays
Details of type relays Main-1 Relay Main-2 Relay (Back-up relays, DR, FL
etc.)
Details of composite type numerical relays
Relay make and model for ex: Siemens 7SA522 P444 REL670
Whether the relay is functional?? Yes/ No YES YES
Date of testing 18.09.2024 18.09.2024
Mention all the active protections 21/87L/67/67N/51/51N/59 21/67/67N/51/51N 21/67/67N/51/51N
Accelerated Under reach/
Permissive Under
reach/Intertripping Under
Mode of Carrier aided scheme for 21
reach/ Permissive Permissive Under reach Permissive Under reach
( If POR scheme is used whether Current Reversal Guard Logic implemented?)
Overreach/ Blocking Over
reach/ Phase Comparison
Protection (for PLCC)

5 Carrier aided scheme active for 67/67N Yes/ No YES YES

Directional Comparison
Protection (Permissive)/
Mode of Carrier aided scheme for 67/67N NO NO
Directional Comparison
Protection (Blocking)
For 87L which scheme is used? (Pilot wire communication/ digital communication) NA NA
Power swing/out of step active? Yes/No YES YES
SOTF active? Yes/No YES YES
Auto Reclose (79) active? Yes/No YES YES
Breaker failure active Yes/ No NO NO
Load Encroachment active Yes/ No YES YES
Stub Protection active Yes/ No NO NO
Fault locator active?
Yes/No YES YES
Disturbance Recorder active? Yes/No YES YES
6 Relay Connected to Trip Coil-1/ Trip Coil-2 or both? Both Both
7 Feed from DC supply 1 / DC Supply 2 DC Supply 2 DC Supply 2
8 Connected to Dedicated CT core? Define CT core no. to which the relay is connected Core-1 Core-2
9 CT ratio selected 800/1 A 800/1 A
10 VT ratio selected 220 kV/110 V 220 kV/110 V

Southern Region - (Station Name) 35/58

 220 kV Thimmapuram-2 Distance Protection Audit - check list
Audited data
No. Relay configuration - Line distance protection
Details of separate relays if applicable
Relay 1 make and model
Auto reclose/ Breaker
Functions available in Relay 1
Failure/ 67/67N/51/51N/59
Relay 1 Functional Yes/ No
Date of Testing
Relay 2 make and model
Auto reclose/ Breaker
Functions available in Relay 2
Failure/ 67/67N/51/51N/59
Relay 2 Functional Yes/ No
11 Date of Testing
NA
Relay 3 make and model
Auto reclose/ Breaker
Functions available in Relay 3
Failure/ 67/67N/51/51N/59
Relay 3 Functional Yes/ No
Date of Testing
Relay 4 make and model
Auto reclose/ Breaker
Functions available in Relay 4
Failure/ 67/67N/51/51N/59
Relay 4 Functional Yes/ No
Date of Testing
Yes/No
12 VT Fuse failure protection present & used to block distance function operation? YES
Overvoltage protection available Yes/ No NO
13 Functional with two stage protection
Yes/No NO
Are all the auxiliary relays (94) considered for Line protection (Main-1/ Main-2/
14 Yes/No YES
Backup) provided with supervision relays (74/ 94) ?
Do the Line Protection protection panels have supervision relays for DC supply-1 &
15 Yes/No YES
DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (Station Name) 36/58

 220/33 kV PTR-1 NGEF Make Transformer Protection Audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power NGEF PTR-1, 220/33 kV, 31.5 MVA
2 Are used 2 groups of protections (Group A and Group B) for transformer protection? Yes /No NO
3 Are Group A and Group B protections connected to separate DC sources for power transformers? Yes /No NO
4 Do the Group A and Group B protections have separate lockout relays? Yes /No YES
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model P643 C264 C264 P643

Whether the relay is functional? Yes /No Yes Yes Yes Yes

Date of testing 31.12.24 31.12.24 31.12.24 31.12.24

Mention all the active protections 87T 51/67N 51/67N 64R

Differential protection Yes NO NO NO

REF protection
NO NO NO NO

Back-up directional O/C +E/F protection NO Yes Yes NO

5
Overfluxing protection NO NO NO Yes
Connected to Trip Coil 1/Trip Coil2/Both
Both Both Both Both
Feed from DC supply 1/DC supply2
DC Supply 1 DC Supply 1 DC Supply 1 DC Supply 1

Breaker failure active Yes /No No No No No

Disturbance Report active Yes /No Yes Yes Yes Yes

Connected to dedicated CT core?
Core-2 Core-1 Core-1 NA
Define CT core no. to which the relay is connected
CT ratio selected 300/1 A,
Yes /No 300/1 A 600/1 A NA
600/1 A
Is CT supervision enabled or not in case of Transformer differential protection ? Yes /No YES
Are all the Lock out relays (86) considered for Transformer protection provided with supervision relays
6 Yes/No YES
(74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No YES
74/DC-2)?
OTI working
8 Yes /No YES
WTI working
9 Yes /No YES

10 Buchholtz working Yes/No YES

11 PRD/ PRV working Yes/No YES

12 LA rating HV side Yes/No 216 KV

13 LA rating IV side Yes/No 36 KV

Southern Region - (220 KV SS Ramagiri) 37/58

 220/33 kV PTR-2 BHEL Make Transformer Protection Audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power BHEL PTR-2, 220/33 kV, 50 MVA

2 Are used 2 groups of protections (Group A and Group B) for transformer protection? Yes /No NO

3 Are Group A and Group B protections connected to separate DC sources for power transformers? Yes /No NO

4 Do the Group A and Group B protections have separate lockout relays? Yes /No YES
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model P643 C264 C264 P643

Whether the relay is functional? Yes /No Yes Yes Yes Yes

Date of testing 31.12.24 31.12.24 31.12.24 31.12.24

Mention all the active protections 87T 51/67N 51/67N 64R

Differential protection Yes NO NO NO

REF protection
NO NO NO NO

Back-up directional O/C +E/F protection NO Yes Yes NO

5
Overfluxing protection NO NO NO Yes
Connected to Trip Coil 1/Trip Coil2/Both
Both Both Both Both
Feed from DC supply 1/DC supply2
DC Supply 1 DC Supply 1 DC Supply 1 DC Supply 1

Breaker failure active Yes /No No No No No

Disturbance Report active Yes /No Yes Yes Yes Yes

Connected to dedicated CT core?
Core-2 Core-1 Core-1 NA
Define CT core no. to which the relay is connected
CT ratio selected 150/1 A,
Yes /No 150/1 A 1200/1 A NA
1200/1 A
Is CT supervision enabled or not in case of Transformer differential protection ? Yes /No YES
Are all the Lock out relays (86) considered for Transformer protection provided with supervision relays
6 Yes/No YES
(74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No YES
74/DC-2)?
OTI working
8 Yes /No YES
WTI working
9 Yes /No YES

10 Buchholtz working Yes/No YES

11 PRD/ PRV working Yes/No YES

12 LA rating HV side Yes/No 216 KV

13 LA rating IV side Yes/No 36 KV

Southern Region - (220 KV SS Ramagiri) 38/58

 765 kV Bus Reactor Protection Audit - check list
No Relay configuration - Shunt reactor protections
1 Name,Voltage,Power

2 Are used 2 groups of protections (Group A and Group B) for shunt reactors protection? Yes /No

3 Are Group A and Group B protections connected to separate DC sources for shunt reactors? Yes /No

4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up Other
Details of type relays
A B C D Protections
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Differential protection

REF protection

5 Back-up directional O/C +E/F protection

Overfluxing protection

Connected to Trip Coil1 / Trip Coil2 / Both

Feed from DC supply 1/DC supply2

Breaker failure active Yes /No

Disturbance Recorder active Yes /No

Connected to dedicated CT core?
Define CT core no.to which the relay is connected
CT ratio selected
Is CT supervision enabled or not in case of Reactor differential protection ? Yes /No
Are all the Lock out relays (86) considered for Reactor protection provided with supervision
6 Yes/No
relays (74/ 86) ?
Do the Reactor protection panels have supervision relays for DC supply-1 & DC supply-2
7 Yes/No
(74/DC-1 & 74/DC-2)?
8 OTI indications working Yes /No

9 WTI indications working Yes /No

10 Bucholtz working Yes/No

11 PRD/ PRV working Yes/No

12 LA rating HV side Yes/No

Southern Region - (Station Name) 39/58

 400 kV Bus Reactor Protection Audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power
2 Are used 2 groups of protections (Group A and Group B) for transformer protection? Yes /No
3 Are Group A and Group B protections connected to separate DC sources for power transformers? Yes /No
4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Differential protection
REF protection

5 Back-up directional O/C +E/F protection

Overfluxing protection
Connected to Trip Coil 1/Trip Coil2/Both

Feed from DC supply 1/DC supply2

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to dedicated CT core?
Define CT core no. to which the relay is connected
CT ratio selected
Yes /No

Is CT supervision enabled or not in case of Transformer differential protection ? Yes /No

Are all the Lock out relays (86) considered for Transformer protection provided with supervision relays
6 Yes/No
(74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No
74/DC-2)?
OTI working
8 Yes /No
WTI working
9 Yes /No

10 Buchholtz working Yes/No

11 PRD/ PRV working Yes/No

12 LA rating HV side Yes/No

Southern Region - (Station Name) 40/58

 765 kV Line Reactor (Line Name) Protection audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power

2 Are used 2 groups of protections (Group A and Group B) for transformer protection? Yes /No

3 Are Group A and Group B protections connected to separate DC sources for power transformers? Yes /No

4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Differential protection
REF protection

Back-up directional O/C +E/F protection

5
Overfluxing protection
Connected to Trip Coil 1/Trip Coil2/Both

Feed from DC supply 1/DC supply2

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to dedicated CT core?
Define CT core no. to which the relay is connected
CT ratio selected
Yes /No

Is CT supervision enabled or not in case of Transformer differential protection ? Yes /No

Are all the Lock out relays (86) considered for Transformer protection provided with supervision relays
6 Yes/No
(74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No
74/DC-2)?

8 OTI indications working Yes /No

9 WTI indications working Yes /No

10 Bucholtz working Yes/No

11 PRD/ PRV working Yes/No

12 LA rating HV side Yes/No

Southern Region - (Station Name) 41/58

 765 kV Line Reactor (Line Name) Protection audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power

2 Are used 2 groups of protections (Group A and Group B) for transformer protection? Yes /No

3 Are Group A and Group B protections connected to separate DC sources for power transformers? Yes /No

4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Differential protection
REF protection

5 Back-up directional O/C +E/F protection

Overfluxing protection
Connected to Trip Coil 1/Trip Coil2/Both

Feed from DC supply 1/DC supply2

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to dedicated CT core?
Define CT core no. to which the relay is connected
CT ratio selected
Yes /No

Is CT supervision enabled or not in case of Transformer differential protection ? Yes /No

Are all the Lock out relays (86) considered for Transformer protection provided with supervision relays
6 Yes/No
(74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No
74/DC-2)?
8 OTI indications working Yes /No

9 WTI indications working Yes /No

10 Bucholtz working Yes/No

11 PRD/ PRV working Yes/No

12 LA rating HV side Yes/No

Southern Region - (Station Name) 42/58

 400 kV Line Reactor (Line Name) Protection audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power

2 Are used 2 groups of protections (Group A and Group B) for transformer protection? Yes /No

3 Are Group A and Group B protections connected to separate DC sources for power transformers? Yes /No

4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Differential protection
REF protection

5 Back-up directional O/C +E/F protection

Overfluxing protection
Connected to Trip Coil 1/Trip Coil2/Both

Feed from DC supply 1/DC supply2

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to dedicated CT core?
Define CT core no. to which the relay is connected
CT ratio selected
Yes /No

Is CT supervision enabled or not in case of Transformer differential protection ? Yes /No

Are all the Lock out relays (86) considered for Transformer protection provided with supervision relays
6 Yes/No
(74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No
74/DC-2)?
8 OTI indications working Yes /No

9 WTI indications working Yes /No

10 Bucholtz working Yes/No

11 PRD/ PRV working Yes/No

12 LA rating HV side Yes/No

Southern Region - (Station Name) 43/58

 400 kV Line Reactor (Line Name) Protection audit - check list
Audited data
No Relay configuration - Power Transformers protections
1 Name, voltage, power

2 Are used 2 groups of protections (Group A and Group B) for transformer protection? Yes /No

3 Are Group A and Group B protections connected to separate DC sources for power transformers? Yes /No

4 Do the Group A and Group B protections have separate lockout relays? Yes /No
Main Back up
Details of type relays Other Protections
A B C D
Details of composite type numerical relays
Relay make and model

Whether the relay is functional? Yes /No

Date of testing

Mention all the active protections

Differential protection
REF protection

5 Back-up directional O/C +E/F protection

Overfluxing protection
Connected to Trip Coil 1/Trip Coil2/Both

Feed from DC supply 1/DC supply2

Breaker failure active Yes /No

Disturbance Report active Yes /No

Connected to dedicated CT core?
Define CT core no. to which the relay is connected
CT ratio selected
Yes /No

Is CT supervision enabled or not in case of Transformer differential protection ? Yes /No

Are all the Lock out relays (86) considered for Transformer protection provided with supervision relays
6 Yes/No
(74/86) ?
Do the Transformer protection panels have supervision relays for DC supply-1 & DC supply-2 (74/DC-1 &
7 Yes/No
74/DC-2)?
8 OTI indications working Yes /No

9 WTI indications working Yes /No

10 Bucholtz working Yes/No

11 PRD/ PRV working Yes/No

12 LA rating HV side Yes/No

Southern Region - (Station Name) 44/58

 Synchro-Check Protection Audit - check list
Audited data
No Relay configuration - Synchro-check protections
Details of type relays
Details of composite type numerical relays
1 Relay make and model NA

2 Whether the relay is functional? Yes /No NA

3 Date of testing NA

4 Voltage measurement Ph-Ph or Ph-N NA

5 What is the set value of voltage difference (∆U) ? % NA

6 What is the set value of Phase angle difference (∆φ ) ? ° NA

7 What is the set value of frequency slip? (Δf) mHz NA

8 What is the set time delay of output relay? (DELAY) sec NA

9 Settings value for dead bus/line % NA

Southern Region - (Station Name) 45/58

 Bus Bar Protection and Breaker Failure Protection Audit - check list
Audited data
No BB and BF protection 220 kV 400 kV 765 kV
BUSBAR PROTECTION
1 Main BB available or not ? Yes/No Yes NA NA

Back-up busbar protection to be provided by either of the following: For 132kV & 220kV NA NA

- Remote -end distance relay overreaching elements (second zone) Yes/No Yes NA NA
2
- Reverse looking element of the local distance relay Yes/No Yes NA NA

- Directional back-up overcurrent relays at remote end. Yes/No Yes NA NA

3 Redundant BBP available or not? Yes/No No NA NA

1 and 1/2 Circuit
No NA NA
Breaker scheme
Single busbar Yes NA NA
4 Type of bus Bar arrangement (Select from the choices)
Double busbar No NA NA
Main-1, Main-2 &
No NA NA
Transfer
Busbar 1 Busbar 2 Busbar 1 Busbar 2 Busbar 1 Busbar 2
(BB1) (BB2) (BB1) (BB2) (BB1) (BB2)
Main 1 relay Make for ex: REB 500 MICOM P743/P741 NA NA

Main 1 relay functional Yes/No Yes NA NA

Low/High
5 Main 1 relay type Low impedance NA NA
impendance
Connected to Trip Coil1 / Trip Coil2 Both NA NA

Feed from DC supply 1/DC supply2 DC Supply 1 NA NA

Main 2 relay Make for ex: REB 500 NA NA NA

Main 2 relay functional Yes/No NA NA NA

Low/High
6 Main 2 relay type NA NA NA
impendance
Connected to Trip Coil 1/Trip Coil2 NA NA NA

Feed from DC supply 1/DC supply2 NA NA NA

7 Trip to both coils in case of one BBP Yes/No Yes NA NA NA

BB1 BB1 BB2 BB2 BB1 BB1 BB2 BB2 BB1 BB1 BB2 BB2
Main-1 Main-2 Main-1 Main-2 Main-1 Main-2 Main-1 Main-2 Main-1 Main-2 Main-1 Main-2
8 Dedicated CT core for each BB protection Yes/No (Core No.) Core-3 NA NA NA NA NA
To be filled for High Impedance busbar protection NA NA
a) Is the high impedance protection used for simple busbar
arrangement like 1 and 1/2 breaker scheme or single busbar Yes/No NA NA NA NA NA NA
arrangement
b) Whether the CT ratios and charcteristics are same (Vk etc.) Yes/No NA NA NA NA NA NA

c) Whether stability check has been conducted? Yes/No NA NA NA NA NA NA

d) Is CT supervision relay provided or not? Yes/No NA NA NA NA NA NA

9

Southern Region - (220 KV SS Ramagiri) 46/58

 Bus Bar Protection and Breaker Failure Protection Audit - check list
No BB and BF protection 220 kV 400 kV 765 kV
9
e) In case of busbar protection where isolator contacts are used for
NA NA NA NA NA NA
zone selectivity/ CT selection, please fill the below items:
- Is check zone enabled or not?? Yes/No NA NA NA NA NA NA
- Is Check zone measurement connected to separate CT cores ? Yes/No NA NA NA NA NA NA

- If check zone Is not enabled, Is the relay setting increased to value

Yes/No NA NA NA NA NA NA
higher than the heaviest loaded feeder current.

To be filled for Low Impedance busbar protection NA NA

a) Centralised BBP Yes/No No NA NA NA NA NA

b) or discentralized BBP with peripheral units? Yes/No Yes NA NA NA NA NA

b) Whether stability check has been conducted? Yes/No Yes NA NA NA NA NA

10
c) Is CT supervision enabled or not ? Yes/No Yes NA NA NA NA NA
d)In case of busbar protection where isolator contacts are used for
NA NA
zone selectivity/ CT selection, please fill the below items:
- Is check zone enabled or not ? Yes/No Yes NA NA NA NA NA
- If check zone Is not enabled, Is the relay setting increased to value
Yes/No NA NA NA NA
higher than the heaviest loaded feeder current.
11 One zone for one bus Yes/No Yes
Are all the Busbar protection Lock out relays (86BB) provided with
12 Yes/No No
supervision relays (74/ 86BB) ?
Do all the Busbar protection panels have supervision relays for DC
13 Yes/No Yes
supply-1 & DC supply-2 (74/DC-1 & 74/DC-2)?
BREAKER FAILURE PROTECTION
14 Breaker failure included in BB protection Yes/No Yes

15 Breaker failure included in Line/transformer protections Yes/No No

16 Separate BFP provided Yes/No No

17 If separate BFP is provided, furnish Make/ Model NA

18 BFP relay functional Yes/No NA

19 BFP conditons: Current presence Yes/No Yes

20 BFP conditons: CB closed position Yes/No No

21 BFP retrip active (first stage) Yes/No Yes

22 Tripping time for BFP (second stage) 0.2s< t <0.3s Yes/No 0.2 s

Are Breaker Failure potection auxiliary relay for Stage-1 (94BF) and
23 Lock out relay for Stage-2 (86BF) provided with supervision relays (74/ Yes/No No
94BF & 74/86BF)
Do all the Breaker Failure protection panels have supervision relays for
24 Yes/No NA
DC supply-1 & DC supply-2 (74/DC-1 & 74/DC-2)

Southern Region - (220 KV SS Ramagiri) 47/58

 DC System Protection Audit - check list
Audited data
No DC supply systems 220V DC 1 48V DC 1
Non Sealed/Sealed lead with
Sealed lead with
1 Type of Batteries recombination of gas/ Non Sealed
recombination of gas
Nickel-Cadmium/Other
2 Number of Cells per bank 110 24

3 Date of procurement/ commissioning of the Battery 18-08-2018

4 Is the battery functional and in good condition? Yes/No Yes Yes

5 Availability of Battery Charger Yes/No Yes Yes

6 Date of procurement/ commissioning of the Charger 18-08-2018

7 Is the Charger functional ? Yes/No Yes Yes

Two sets of battery and charger
8 Used combination for charging /single battery with charger Single Battery with ChargerSingle Battery with Charger
/one battery with two chargers
Measured voltage (to be measured at the farthest panel)

9 Positive to Earth 118 0

Negative to Earth -120 -48

10 Availability of Battery Ground Fault Detectors? Yes/No Yes No

The protection relays and trip circuits are segregated into two
12 independent system feed through fuses from two different DC Yes/No Non sealed Yes
sources
Maintenance/ Testing Plan

13 Daily: Note down of pilot cell readings

What is the maintenance/testing plan/schedule followed by the utility
Weekly: Cleaning of cells
for maintenance of battery and charger?
Twice a Month: Load test by turning off AC supply

Southern Region - (220 KV SS RAMAGIRI) 48/58

 AC System Protection Audit - check list
Audited Data
No AC Supply System Supply I

Source of AC HT supplies Name of Source From 33 KV Bus (with in the SS)

1
In case of two AC HT supplies,the supplies are arranged from independent sources Yes/No NA

Voltage/Source of supply 33 kV

Supply changeover method between Supply I and Supply II Auto/Manual NA

DG
DG available Yes/No Yes
DG:Make and rating power Eicher, 25 KVA

2 All Circuit breakers, Isolators, Battery charger, all C&R

What loads are supplied by the DG ?
panles, Lighting

DG starting is Auto/manual Auto/Manual Manual

Supply changeover method between Normal AC Supply and DG Manual
3 The SS to furnish the supply changeover scheme/ single line diagram Yes (Attached)
Maintenance/Testing Plan

Daily: Trail run for 10 minutes, checking of battery

conditions
4 Weekly: Maintenance of DG set battery
What is the maintenance plan/ schedule followed by the utility for maintenance of DG ?
Monthly: Checking various oil levels and leaks if any and
air leaks
Yearly: Change of engine oil or every 300 hours.

Southern Region - (Station Name) 49/58

 Communication System Protection Audit - check list
Audited data
No Communication System 220 kV System 132 kV System
a) Type of communication for Main-1 Protection PLCC/ OPGW PLCC
b) Type of communication for Main-2 Protection PLCC/ OPGW PLCC
1
c) Mode used for Data communication OPGW
d) Mode used for Speech communication OPGW
PLCC Details
a) Do you use PLCC for teleprotection of distance relays ? Yes/No Yes
b) Specify type of Coupling Ph-Ph/ Ph-G/ Inter-Circuit Ph-Ph
c) Whether redundant PLCC channels provided for 400 kV & 765 kV
Yes/ No NA
lines
d) Specify number of PLCC channels per circuit One/ Two One
2 e) No. of protection channels One/circuit
No. of data channels Two
No. of speech channels Two
f) Whether dependability & security of each tele-protection channel
Yes/No Yes
measured and record kept?
g) Is the PLCC equipment and channels healthy & functional Yes/No Yes
OPGW Details
a) Redundancy maintained by providing two sets of Fibre Optic
Yes/ No No
Equipment
b) Card level redundancy (Power supply card, protection card, CPU
Yes/ No Yes
3 board) maintained in each fibre optic equipment
c) Separate DC battery supply or common DC battery supply
Yes/No Yes
separately fused for each fibre optic equipment.
d) Are the Fibre Optic equipment and channels healthy & functional Yes/No Yes
e) OPGW on geographically diversified paths for Main-1 and main-2
Yes/No No
relay
Time Synchronization Equipment Details
a) Whether GPS based time synchronizing equipment is provided at
the substation for time synchronizing of Main relays/ DR/ Event Yes/ No No
logger/ SAS/ PMU/ Line Current Differential Relays
b) Are Time Synchronization Equipment (TSE) complete with
4 antenna, all cables, processing equipments etc. provided to receive
synchronizing pulse through Global Positioning system (GPS) Yes/ No No
compatible for synchronization of event logger, disturbance recorder
and SCADA/ automation system.
c) Are the Main Relays/ DR/ Event Logger/SAS/ PMU/ Line current
Yes/ No No
differential relays time synchronized.

Southern Region - (Station Name) 50/58

 Communication System Protection Audit - check list
Audited data
Disturbance Recorder and Event Logger Details
Check all these items for individual relay.
a) Is the Disturbance recorder provided on all the feeders of 765kV,
Yes/ No No
400 kV & 220 kV Substations?
b) Is the Fault locator provided on all the line feeders of 765kV, 400
Yes/ No part of main relay
kV & 220 kV Substations?
5 c) Whether the Disturbance recorder is Standalone or part of main Yes/ No part of main relay
relay
d) Whether Disturbance Recorder is having automatic fault record
Yes/ No No
download facility to a central PC
e) Disturbance Recorders functional ? Yes/ No Yes
f) Whether substation (765, 400, 220 kV) is having Event Logger
stand alone/ built-in-SAS NA
facility (stand alone or built-in-SAS)
g) Event Logger functional ? Yes/ No part of main relay

Southern Region - (Station Name) 51/58

 Circuit Breaker Protection Audit - check list
Audited data
No. CB ID Bay Name 1 2 3
1 CB Rated voltage (KV) 220 kV 220kV 220kV

2 CB ID Bay Name ANANTAPUR SHAPURAM MUTTALA-1

3 Make & Model SIEMENS 3AP2F1 SIEMENS 3AP2F1 ALSTOM GL314

4 Date of commissioning 21-03-2020 31-01-2021 31-10-2013

5 Type of CB (SF6/ MOCB/ ABCB etc.) SF6 SF6 SF6

6 Is the Breaker healthy/ functional (Yes/ No) YES YES YES

7 Rated Breaking current (kA) 50 KA 50 KA 40 kA

8 Number of closing coils 1 1 1

9 Healthiness of closing coil GOOD GOOD GOOD

10 Number of tripping coils 2 2 2

11 Healthiness of Tripping Coil GOOD GOOD GOOD

Trip Circuit Supervision Relay available for monitoring Trip Circuit -1 & Trip Circuit-2 with
12 YES YES YES
breaker in both open and closed condition (Yes/ No)
13 Are the Trip Circuit Supervision realys functional/ healthy YES YES YES

14 One/three pole operation ONE & THREE ONE & THREE ONE & THREE

15 For breakers with single poles, is pole discrepancy relay provided? YES YES YES
Does the Pole discrepancy relay have facility for Stage-1 (own breaker tripping) &
16 NO NO NO
Stage-2 (Boundary breaker tripping)
What monitoring devices are provided for checking the dielectric medium of the SF6 Density SF6 Density SF6 Density
17
breaker? (for eg. Gas pressure low etc.) Monitor Monitor Monitor
What action is initiated by each of different Stages of these devices (Alarm/ Block Alarm/ Block Alarm/ Block Alarm/ Block
18
tripping) tripping tripping tripping
19 PIR (Available/ Not) NO NO NO

Southern Region - (220 KV SS RAMAGIRI) 52/58

 Circuit Breaker Protection Audit - check list
Audited data
No. CB ID Bay Name 4 7 8
1 CB Rated voltage (KV) 220kV 220kV 220kV

2 CB ID Bay Name MUTTALA-2 31.5 MVA-1 50 MVA-2

3 Make & Model ALSTOM GL314 ABB ELFSL4-1 ABB ELFSL4-1

4 Date of commissioning 20-04-2015 31-10-1995 31-10-1995

5 Type of CB (SF6/ MOCB/ ABCB etc.) SF6 SF6 SF6

6 Is the Breaker healthy/ functional (Yes/ No) 0 YES YES

7 Rated Breaking current (kA) 40 kA 40 kA 40 kA

8 Number of closing coils 1 1 1

9 Healthiness of closing coil GOOD GOOD GOOD

10 Number of tripping coils 2 2 2

11 Healthiness of Tripping Coil GOOD GOOD GOOD

Trip Circuit Supervision Relay available for monitoring Trip Circuit -1 & Trip Circuit-2 with
12 YES YES YES
breaker in both open and closed condition (Yes/ No)
13 Are the Trip Circuit Supervision realys functional/ healthy YES YES YES

14 One/three pole operation ONE & THREE THREE THREE

15 For breakers with single poles, is pole discrepancy relay provided? YES YES YES
Does the Pole discrepancy relay have facility for Stage-1 (own breaker tripping) &
16 NO NO NO
Stage-2 (Boundary breaker tripping)
What monitoring devices are provided for checking the dielectric medium of the SF6 Density SF6 Density SF6 Density
17
breaker? (for eg. Gas pressure low etc.) Monitor Monitor Monitor
What action is initiated by each of different Stages of these devices (Alarm/ Block Alarm/ Block Alarm/ Block Alarm/ Block
18
tripping) tripping tripping tripping
19 PIR (Available/ Not) NO NO NO

Southern Region - (220 KV SS RAMAGIRI) 53/58

 Current Transformer Protection Audit - check list
Audited data
In case of a
protection CT, is the
CT ratio Connected to Knee
CT ID Accuracy Protection/ Ratio relay setting Date of CT Ratio Error
No Voltage level CT core (All available ratios for a which relays/ Point
Bay Name Class Metering Adopted calculation done Testing measured Calculated
multi-ratio CT) meters? Voltage
based on the CT
Ratio adopted at site
Main-1 Distance
Core-1 PS Protection 800-600-400/1 A 800/1 A Yes
protection
Main-2 Distance
Core-2 PS Protection 800-600-400/1 A 800/1 A Yes
1 220 KV ANANTAPUR 220 KV protection
Bus bar
Core-3 PS Protection 800-600-400/1 A 800/1 A Yes
protection
Core-4 PS Protection 800-600-400/1 A ~ Spare
Core-5 0.5 Metering 800-600-400/1 A 800/1 A Metering
Main-1 Distance
Core-1 PS Protection 800-600-400/1 A 800/1 A Yes
protection
Main-2 Distance
Core-2 PS Protection 800-600-400/1 A 800/1 A Yes
2 220 KV SHAPURAM 220 KV protection
Bus bar
Core-3 PS Protection 800-600-400/1 A 800/1 A Yes
protection
Core-4 PS Protection 800-600-400/1 A ~ Spare
Core-5 0.5 Metering 800-600-400/1 A 800/1 A Metering
Main-1 Distance
Core-1 PS Protection 800-400-200/1 A 800/1 A Yes
protection
Main-2 Distance
Core-2 PS Protection 800-400-200/1 A 800/1 A Yes
3 220 KV MUTTALA-1 220 KV protection
Bus bar
Core-3 PS Protection 800-400-200/1 A 800/1 A Yes
protection
Core-4 PS Protection 800-400-200/1 A ~ Spare
Core-5 0.2S Metering 800-400-200/1 A 800/1 A Metering
Main-1 Distance
Core-1 PS Protection 800-400-200/1 A 800/1 A Yes
protection
Main-2 Distance
Core-2 PS Protection 800-400-200/1 A 800/1 A Yes
4 220 KV MUTTALA-2 220 KV protection
Bus bar
Core-3 PS Protection 800-400-200/1 A 800/1 A Yes
protection
Core-4 PS Protection 800-400-200/1 A ~ Spare
Core-5 0.2S Metering 800-400-200/1 A 800/1 A Metering
Core-1 5P20 Protection 300/1 A O/L & E/L Yes
Differential
Core-2 PS Protection 300/1 A Yes
Protection
500,300/1-1,0.66-1,0.5,0.375-1,0.5,0.375- 300/0.375 Bus bar
9 31.5 MVA -1 220 KV Core-3 PS Protection 1A Yes
A protection
Core-4 PS Protection ~ Spare
Core-5 0.2S Metering 300/1 A Metering
Core-1 5P20 Protection 150/1 A O/L & E/L Yes
Differential
Core-2 PS Protection 150/1 A Yes
150/1-1,0.48-1,0.25,0.187-1,0.25,0.187-1 Protection
10 50 MVA-2 A 150/0.187 Bus bar
Core-3 PS Protection Yes
A protection
Core-4 PS Protection ~ Spare
Core-5 1 Metering 150/1 A Metering

Southern Region - (Station Name) 54/58

 Voltage Transformer Protection Audit - check list
Voltage Transformer details
Audited data
Is the relay setting
calculation and relay
configuration files based For Synchrocheck relays, is
CVT/VT Protection Date of
CVT/VT Accuracy Connected to which on the VT Ratio? the VT Input connected Ratio Error
No ID / Ratio VT
core Class relays? (Applicable for VTs Ph-Ph or Ph- Neutral measured Calculated
Bay Name Metering Testing
connected to distance (Which phases R/Y/B?)
protection/ synchro check
relays)
220 kV/110
Core - 1 Metering 0.5 Metering ~
V
Main-1 & Main-2
220 KV BUS PT 220 kV/110 Distance relays,
1 Core - 2 Protection 3P Yes
V Transformer Overflux
and HV Backup relays
Core - 3 ~ ~ ~ ~ ~
Core - 1 Metering 220 kV/110 V 0.2 Metering ~
Core - 2 Protection 220 kV/110 V 0.5 Spare ~
3 220 KV ANANTAPUR
Main-1 & 2 Distance
Core - 3 Protection 220 kV/110 V 3P Yes
Protection
Core - 1 Metering 220 kV/110 V 0.2 Metering ~
Core - 2 Protection 220 kV/110 V 0.5 Spare ~
4 220 KV SHAPURAM
Main-1 & 2 Distance
Core - 3 Protection 220 kV/110 V 3P Yes
Protection
Core - 1 Metering 220 kV/110 V 0.2 Metering ~
Main-1 & 2 Distance
5 220 KV MUTTALA-1 Core - 2 Protection 220 kV/110 V 3P Yes
Protection
Core - 3 Protection 220 kV/110 V 3P Spare ~
Core - 1 Metering 220 kV/110 V 0.2 Metering ~
Main-1 & 2 Distance
6 220 KV MUTTALA-2 Core - 2 Protection 220 kV/110 V 3P Yes
Protection
Core - 3 Protection 220 kV/110 V 3P Spare ~

Southern Region - (220 KV SS RAMAGIRI) 55/58

 HVDC Protection Audit - check list
Audited data
No HVDC configuration system Collected value
1 Configuration nework type Back to back/Bipolar/Monopolar NA
Double bus scheme with one and half breaker
2 Configuration type of bus switching scheme switching/Double bus scheme with two breaker NA
switching
3 Transmission distance NA
4 Type of plant Underground cable/Submarine cable/Overhead line NA
5 Type of semiconductors IGBT/GTO NA
6 Voltage AC level NA
7 Voltage DC level NA
8 Power of HVDC transmission NA
9 Convertors type NA
10 Firing angle(α) 0⁰/45⁰/60⁰/90⁰/150⁰ NA
Main Back up
Details for converter transformer protection Other Protections
A B A B

Relay make and model NA

Whether the relay is functional? Yes /No NA

Date of testing NA
Mention all the active protection 87/67/67N/51/51N… NA
- differential protection NA
- REF protection NA
11 - Back-up directional O/C +E/F protection NA
- Overfluxing protection NA
Connected to Trip Coil 1/Trip Coil2/Both NA
Feed from DC supply 1/DC supply2 NA
Breaker failure active Yes /No NA
Disturbance Report active Yes /No NA
Connected to dedicated CT core?
Yes /No NA
Define CT core no.to which the relay is connected
CT ratio selected NA
Is CT supervision enabled or not in case of Converter Transformer
Yes /No NA
differential protection ?
Are all the Lock out relays (86) considered for Converter Transformer
12 Yes/No NA
protection provided with supervision relays (74/ 86) ?
Do the Converter Transformer protection panels have supervision relays
13 Yes/No NA
for DC supply-1 & DC supply-2 (74/DC-1 & 74/DC-2)?
OTI/WTI indications working Yes /No NA
14
Bucholtz/PRD working Yes/No NA

Southern Region - (220 KV SS RAMAGIRI) 56/58

 HVDC Protection Audit - check list
Audited data
No HVDC configuration system Collected value
Main Back up
Details of filter bank protections Other Protections
A B A B
Relay make and model
Whether the relay is functional? Yes /No
Date of testing
Mention all the active protection
- differential protection
- Overcurrent protection
- Unbalance protection
15
Used like Main or Back-up protection -
Connected to Trip Coil 1/Trip Coil2/Both
Feed from DC supply 1/DC supply2
Breaker failure active Yes /No
Disturbance Report active Yes /No
Connected to dedicated CT core?
Yes /No
Define CT core no.to which the relay is connected
CT ratio selected
Is CT supervision enabled or not in case of differential protection ? Yes /No
Are all the Lock out relays (86) considered for Filter Bank protection
16 Yes/No
provided with supervision relays (74/ 86) ?
Do the Filter Bank protection panels have supervision relays for DC
17 Yes/No
supply-1 & DC supply-2 (74/DC-1 & 74/DC-2)?

Southern Region - (220 KV SS RAMAGIRI) 57/58

 General Remarks

Sl. No. Deficiences/ Non-conformities observed

10

11

12

13

Southern Region - (Station Name) 58/58