ALAI KHWAR POWER HOUSE SWITCHYARD
TSG North NTDC DISTANCE, AUTO RECLOSER & EARTH FAULT TEST REPORT

Auto Recloser Relay Set-1 (Internal Feature of SEL 421 Distance Relay) installed on 220kV Alai – Mansehra
Circuit 1
 Bus CB AR Dead time = 1.3 sec (Live Line / Live Bus reclosing condition)
 Middle CB AR Dead time = 10 Sec (Live Line /Live Bus reclosing condition)
 Reclaim Time = 180 sec or Maximum available
Auto Recloser Set-I (Internal Feature of SEL 421) tested and following conditions applied from
Distance Set-I (SEL 421).
Sr. Conditions of CB before
No. Fault Injection
1
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
Fault Injected
2
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
Aided Trip Phase to Ground
3
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
Aided Trip Phase to Phase
Fault
4
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
Aided Trip three Phase Fault
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
D1Q1 C.B Closed (Dead
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus)
Z1 three Phase Fault
5
6
7
8
9
Z1 Phase to Ground
Condition of C.B after
fault injection
D1Q1 C.B tripped and
reclosed after 1.3 sec,
D1Q3 tripped and
reclosed after 10
seconds.
D1Q1 C.B tripped and
reclosed after 1.3 sec,
D1Q3 tripped and
reclosed after 10
seconds.
D1Q1 C.B tripped and
reclosed after 1.3 sec,
D1Q3 tripped and
reclosed after 10
seconds.
D1Q1 & D1Q3 CB
Tripped only.
Z1 Phase to Ground fault
injected in Reclaim time
D1Q1 & D1Q3 CB
Tripped only.
Z1 Phase to Phase Fault
D1Q1 C.B tripped and
reclosed after 1.3 sec,
D1Q3 tripped and
reclosed after 10
seconds.
D1Q1 & D1Q3 CB
Tripped only.
Z2 Phase to Ground + Z2
Phase to Phase +Z3 Phase to
Ground + Z3 Phase to Phase+
SOTF Faults injected
Z1 Phase to Ground
D1Q1 & D1Q3 CB
Tripped only.
D1Q1 CB Tripped and
not reclosed. While
D1Q3 reclosed
immediately after the
10
11
D1Q1 C.B Open(Live Line
and Live Bus), D1Q3 C.B
Closed (Live Line and
Live Bus) (Priority
Reversal)
D1Q1 C.B Closed (Live
Line and Live Bus), D1Q3
C.B Closed (Live Line
and Live Bus), AR Out of
Service
Z1 Phase to Ground
Z1 Phase to Ground Fault
sync supervision time of
Q1 i.e 5 seconds and
did not wait for 10
seconds to reclose due
to dynamic selection of
Leader and Follower
breaker by the relay.
D1Q3 CB reclosed after
1.3 seconds as the
Leader breaker.
D1Q1 & D1Q3 CB
Tripped only.
Remarks / Observations:
1. Distance Set 1 (SEL 421) relay is initiating and blocking Auto Recloser Set I (Internal
Feature of SEL 421) as per Protection and Control Department Setting. PUTT scheme
of the relay is also tested and found satisfactory.
2. End to End Tele protection scheme (PUTT & DTT) testing have been done.
3. Distance Zone reach and timing report & Earth Fault relay (SEL 351) testing report is
attached separately with this report.
Tested By: Mr. Sumair Memon Sb
Designation: D.M (P&M) TSG NTDC
Tested By: Mr. Fahimuddin Qureshi
Designation: A.M (P&M) TSG NTDC
Witnessed By: Mr. Hidaya ul Allah
Designation: Senior Engineer (EME)
Alai Khwar Power House Switchyard