7. TESTING ADDITIONAL FUNCTIONAL TESTING
7-13
7.3.5
SHORT CIRCUIT TEST
The SR469 specification for short circuit timing is +40ms or ±0.5% of total time. The pickup accuracy is as per the phase current inputs. Per-
form the steps below to verify the performance of the short circuit element.
1. Alter the following setpoints:
SETPOINT S2:SYSTEM SETUP\CURRENT SENSING\PHASE CT PRIMARY: 1000
SETPOINT S6:CURRENT ELEMENTS\SHORT CIRCUIT TRIP\SHORT CIRCUIT TRIP: On
SETPOINT S6:CURRENT ELEMENTS\SHORT CIRCUIT TRIP\ASSIGN TRIP RELAYS: Trip
SETPOINT S6:CURRENT ELEMENTS\SHORT CIRCUIT TRIP\SHORT CIRCUIT TRIP PICKUP: 5.0 x CT
SETPOINT S6:CURRENT ELEMENTS\SHORT CIRCUIT TRIP\INTENTIONAL S/C DELAY: 0
2. Inject current as per the table below, resetting the unit after each trip by pressing the [RESET] key, and verify timing accuracy. Pre-trip
values may be viewed by pressing the [NEXT] after each trip.
Table 7-18 SHORT CIRCUIT TIMING
INJECTED
CURRENT
5A UNIT
(A)
INJECTED
CURRENT
1A UNIT
(A)
EXPECTED
TIME TO TRIP
(ms)
MEASURED
TIME TO TRIP
(ms)
30 6 <40
40 8 <40
50 10 <40
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