1
66ELECTRICITY DISTRIBUTION DEPARTMENT
MAINTENANCE SECTION
(Distribution Protection)
PRE COMMISSIONING TEST REPORT FOR
RESTRICTED EARTHFAULT
PROTECTION, MV CONSUMER PANEL
Project
Name
Name of substation: Planning Number ..
MV Panel make :..Serial no. ..
.
Panel supplier Name . Tele.
no..
Name of Contractor' Tele.
no..
Name of Consultant... Tele. no
Name of CS Engineer ............................Tele .no
Date of Testing ..
Relay Details:
Name of Relay
Relay Make:
Serial No.
Type
Current
rating
Voltage rating
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Make:
Ratio
Class
Knee point V (Vkp)
In at Vkp
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Current Transformer Details:
Serial Numbers
Red CT
Yellow CT
Blue CT
Neutral CT
-----------------------------------------------------------------------------------------
Details of Power Transformer:
Transformer No.
Capacity
Voltage
% Impedance (Z%)
Make
-----------------------------------KVA
11KV/ ---------------------- %
---------------------
(Telephone: 4845623-5622 Fax 4845707)
EDM/PR /MV-01
Vector Group
--------------------Year of Manufacture ---------------------Resistance of CT
R Phase
Y Phase
B - Phase
Neutral
----------------------------------------------------------------------------------
Lead resistance
Red
Yellow
Blue
Neutral
-------------------------------------------------------------------------------------------
Resistance of relays:
Current Setting
0.5A
1.0 A
2A
Resistance
Ohm
------------Ohm
------------Ohm
Relay current setting (Iop)
Value of Stabilizing resistance
Amp
Ohm
For Stable Operation of the REF relay the following condition should be
satisfied
I op (Rst + Rr)
>
Ifs (Rct + 2 Rl)
Where
Iop
Rst
Rr
IFs
IF
Ifs
Rl
Relay Setting Current
Value of Stabilizing Resistance
Resistance of Relay at Current Setting
Maximum Secondary Current during the fault
Maximum Fault Current
IF/ CT ratio
Resistance of CT loads
IF = TX capacity / 3 V x pu Impedance
CT knee point requirement calculation
Vkp = 2 x Iop (Rst+Rr+2RL)
Minimum VKp should be as above equation
Where Vkp
= Minimum knee joint voltage
Iop
= Relay setting current
Rst
= Stabilizing resistor
(Telephone: 4845623-5622 Fax 4845707)
EDM/PR /MV-01
Rr
2RL
= Relay resistance
= Loop resistance
1. MAGNETISATION TESTS OF CTS
R Phase
Voltag Curren
e
t
In
In Milli
volts
Amps
Y-Phase
Voltag Current
e
in Milli
in
Amps
Volts
B Phase
Voltage
Current
In volts
In Milli
Amps
Neutral
Voltag
Current
e
In Milli
In
Amps
volts
Note :-To prove the knee point, graph should be Plotted and attached
2. SECONDARY INJECTION OF THE RELAY
Setting
0.5
075
1.0
1.25
1.50
1.75
2.00
Pickup
(Telephone: 4845623-5622 Fax 4845707)
EDM/PR /MV-01
3. RELAY STABILITY TEST
Primary
current
(Refer Fig a)
Relay
Current
Red
CT Current (Clip-on Measurement)
Yellow
Blue
Neutral
Injected
R-N
Y-N
B-N
4. RELAY UNSTABLE TEST (Refer fig b)
Primary
current
Injected
Relay
Curre
nt
Red
CT Current (Clip-on Measurement)
Yellow
Blue
Neutral
R-N
Y-N
B-N
1. Confirm the S1 -S2 of CTs are connected as shown in the drawing.
2. Confirm neutral CT connected between the TX neutral Point and
earthing connection of Neutral as shown in the diagram.
R
Y
B
N
S1
S2
S1
S2
S1
S2
S1
S2
Fig (a)
Inject current through R-N ,Y-N & B-N and record the values in table 3
(Telephone: 4845623-5622 Fax 4845707)
EDM/PR /MV-01
S1
S2
S1
S2
S1
S2
S1
S2
Fig (b)
Inject current through R-N, Y-N & B-N and record the values in table 4
Battery and Battery charger Make..
Confirm the Battery charger and Battery voltage Volts
Name & Signature of Testing Engineer: .
Details of Test used for the Stability check
1. Primary Injection Test Serial Number.Rated Current..
2. Ammeter/voltmeterSerial Numbers..
3. Secondary Injection test Kit Serial Number..
We the undersigned undertake herein
1. The Reliability of MV Panel REF Protection scheme stability and test
results is in compliance with the approved specification and the test results
achieved by testing as per the KM guidelines
2. In violation of the above mentioned commitment, KM has the right to
initiate all legal proceedings liable under such violation.
3. This acknowledgment is subjected to and interrupted in accordance with
Qatari law.
Panel Manufacturer
.
CR. Number.
Name& Signature,..
Date
Stamp
(Telephone: 4845623-5622 Fax 4845707)
EDM/PR /MV-01
Contractor
CR
.Number.
Name &Signature
Date.
Stamp
Consultant..
License Number
Name &Signature
Date
Stamp
Approval from Protection
Remarks
..
.
Name & Signature of Protection Engineer
Senior protection Engineer.Tele
4628682/4628623
Kbs/nkk
(Telephone: 4845623-5622 Fax 4845707)
EDM/PR /MV-01
