LT SWITCHBOARD CHECKLIST
EPCC: S/S: Date:
SWITCHBOARD:
S. Activities Done / Remarks
N. Not
done
A. CT check:
1. CT ratio, VA, CL, Rct, Error check
2. Metering CT class & VA (e.g. CL-0.5, VA-
15)
3. Protection class (e.g. CL- 5P10, VA-15)
B. Primary Injection test:
1. Over Current operation
2. Earth fault- operation
3. Earth fault- stability
4. PCC: REF CT test- Operation
5. PCC: REF CT test- Stability
6. CBCT & SEF CT -operation
7. MCC: Protection relay check- O/C,E/F,
U/B, NPS, Relay output contact
checking,
C. Metering circuit check through PI
1. Energy meter current check
2. Panel Ammeter current check for all
phases
3. Field Ammeter current check
D. Secondary Injection test
1. Numerical relay feeder protection-
O/C, E/F, U/V, Under frequency, NC/NO
Check
2. Numerical relay motor protection-
Thermal O/L, S/C, E/F, U/V, U/F.
3. Auxiliary Relay- Pick up and drop off
voltage, NC/NO contact checking
E. Control scheme checking-Outgoing
feeders
1. Scheme checking as per attached
annexure-A
2. PCC: Inter-trip checking with upstream
breaker
(If downstream MCC commissioned)
3. Separate tripping command from relay
for-86 & Breaker trip coil
F. Control scheme checking-Motor feeders
1. Scheme checking as per attached
annexure-A
2. PCC: U/V tripping of motor
3. PCC: Blocking logic check of U/V trip
command
4. IR and continuity checking of control
cables (Incl. LCS)
5. PCC: Separate tripping command from
relay for-86 & Breaker trip coil
6. Tripping of motor feeder directly through
Emergency push button (without any
multiplier/relay DI DO)
7. PCC: Direct breaker tripping of motor on
under voltage protection without master
relay (86)
8. PCC: Undervoltage of motor tripping
through self-reset relay. (In case of MCC:
no latched contact should be used in the
under-voltage tripping scheme.
9. CBCT and ELR relay checking through
primary injection
S. Activities Done / Remarks
N. Not
done
G. Control scheme checking-Incomer
1. Scheme checking as per attached
annexure-A
2. U/V tripping of Incomer
3. Blocking logic check of U/V trip command
4. U/V trip blocking if another Incomer also
sensing U/V
5. U/V trip blocking if another incomer is in
off condition
6. Inter-trip checking with upstream breaker
(If upstream commissioned)
7. IR and continuity checking of control cable
of inter-trip
8. Separate tripping command from relay for-
86 & Breaker trip coil
9. In case of REF protection used (incomer
fed by Transformer), REF should directly
trip breaker instead of 86 master relay
H. Control scheme checking-Bus coupler
1. Scheme checking as per attached
annexure-A
2. Interlock checking of all the BI coming
from Incomer panel and bus PT as per A/C
scheme logic
a. Incomer ON/OFF status
b. Incomer Test/ Service position
c. Incomer voltage status
d. Bus PT Voltage status
e. Incomers 86 blocking in A/C scheme
3. Auto changeover logic checks in Auto
4. Changeover scheme in Manual (check
synch contact should be used in the
scheme)
5. Bus coupler on logic checks in dead bus
6. Blocking of Auto changeover after time
delay
7. Blocking of bus coupler closing in case of
86 operation
I. DC system
1. DC auto changeover scheme checking
2. Marking of all fuse ratings on inside panel
with application details
3. Check fuse coordination and fuse rating as
per drawing of each panel
4. Control supply of relay shall be different
from breaker control supply
5. Check DC control supply supervision
6. Check no breaker tripping in case of DC off
J. Other points
1. Type test report: Match panel type, fault
rating (short circuit capacity)
2. IR and CRM test report
3. Breaker service position should not be in
tripping scheme
4. Watchdog contact used for alarm purpose
5. Bus bar marking at the back side
6. MCCB dip switch setting either disabled or
set at higher than relay setting (if relay
used in the scheme).
7. Component rating check:
Fuse/Contactor/SFU/MCB
8. Breaker sliding contact checking (NC/NO)
9. Wherever release provided in breaker,
defeat it.
K. Reacceleration scheme checking
1. Simulation checking
2. Timer set values
L. Alarm checking-
Shall be separately checked depending on the
annunciator panel installation
Annexure-A Checklist for scheme checking of LT Panel
Remar
SN Description (Yes/No) Result
ks
Auxiliary supply (AC/DC) distribution
1 checking of all equipment
Stabilizing resistor range checking (if
2 used)
3 Numerical relay grounding status
Circuit breaker test and service position
4
indication and contact checking
Bus PT in service position with MCB BI
5
checking at relay
Local/Remote switch status BI checking
6 at relay
7 86 Not operated BI checking at relay
8 Ethernet cable availability
9 CB Anti pumping relay checking
CB operation (ON & OFF) through ECS
10 and Remote contact shorting
Interlock checking- Load shedding
inhibits from ECS, Close permissive from
11
DS, Main relay healthy, EMG PB and all
future interlocks
Breaker trip checking- by relay, TNC,
ECS, 86 Trip from D/S or U/S, All future
12 trips, df/dt stage, U/V, from field EMG
STOP PB, Load shedding Trip, Master
relay
Breaker closing inhibit by Load shedding
13 contact
CB Trip Circuit supervision checking in
14 both BKR ON & OFF condition
VAJH23 trip checking- through relay,
15 64R, 51G trip and all future trip through
TB shorting
16 Indication circuit checking
i Breaker spring charged
ii BKR ON
iii BKR OFF
vi AUTO TRIP
vii AC SUPPLY FAIL
viii TRIP CIRCUIT HEALTHY
ix BKR IN SERVICE
x BKR IN TEST
xi LINE EARTH TRUCK IN SERVICE
17 4-20mA signal check by secondary
injection
18 Cable cover MIL Coil function checking
AC circuit checking as per drawing
19 scheme
20 Breaker spare contacts checking
ECS Signals through marshalling panel
21 contacts checking
CB ON & OFF operation checking
22 through TNC
