4
Testing the tripping function
Long-time delayed tripping test
The long-time delay tripping function and the trip unit
circuitry can be tested using the test device.
1. Charge the circuit breaker
2. Close the circuit breaker
3. Press the [L] button
The circuit breaker will trip after the set long-time delay time,
plus approximately two seconds processing time, has elapsed.
When the test device successfully completes the test, the
"ETU STATUS" LED will light up continuously green. If the test
is not successful, the tester will indicate that by flashing the
LED. Flashing codes are listed in Table 1.
Short-time delayed tripping test
The short-time delay tripping function and the trip unit
circuitry can be tested using the test device.
1. Charge the circuit breaker
2. Close the circuit breaker
3. Press the [S] button
The circuit breaker will trip after the set short-time delay
time, plus approximately two seconds processing time, has
elapsed. When the test device successfully completes the test,
the "ETU STATUS" LED will light up continuously green. If the
test is not successful, the tester will indicate that by flashing
the LED. Flashing codes are listed in Table 1.
Instantaneous tripping test
The instantaneous tripping function and the trip unit circuitry
can be tested using the test device.
1. Charge the circuit breaker
2. Close the circuit breaker
3. Press the [I] button
The circuit breaker will trip after approximately two seconds
processing has elapsed. When the test device successfully
completes the test, the "ETU STATUS" LED will light up
continuously green. If the test is not successful, the tester will
indicate that by flashing the LED. Flashing codes are listed in
Table 1.
Neutral conductor tripping test
The long-time delay tripping function for the neutral
conductor and the trip unit circuitry for ETU types 727-776
can be tested using the test device. The current sensor for the
neutral conductor must be attached
and the "Neutral
conductor protection" function must be switched on.
1. Charge the circuit breaker
2. Close the circuit breaker
3. Press the [N] button
The circuit breaker will trip after the set long-time delay time
plus approximately two seconds processing time, has elapsed.
When the test device successfully completes the test, the "ETU
STATUS" LED will light up continuously green. If the test is not
successful, the tester will indicate that by flashing the LED.
Flashing codes are listed in Table 1.
Ground-fault tripping test
The ground-fault tripping function and the trip unit circuitry
of ETU types 745-746 with an installed ground-fault
protection module (with tripping function WLGFM48 or
WLGFM76) can be tested using the test device. The current
sensor for the neutral conductor and/or the iron-core ground-
fault sensor must be attached.
1. Charge the circuit breaker
2. Close the circuit breaker
3. Press the [G] button
The circuit breaker will trip after the set ground-fault tripping
delay time, plus approximately two seconds processing time,
has elapsed. When the test device successfully completes the
test, the "ETU STATUS" LED will light up continuously green. If
the test is not successful, the tester will indicate that by
flashing the LED. Flashing codes are listed in Table 1.
DANGER
!
Hazardous Voltage.
Will cause death or serious injury.
Qualified personnel only.
Disconnect and lock off all power before
working on this equipment.
• Always work on de-energized
equipment.
• Always de-energize before
performing any tests, maintenance,
or repair.
• Follow safety related work practices,
as described in NFPA 70E, at all times.
NOTICE
Erroneous test results may occur when the trip
unit is powered by either:
• Load current
• External 24 vdc control power
All testing should be conducted with the primary
bus de-energized, and external 24 vdc control
power disconnected or turned off.
DANGER
!
Hazardous Voltage.
Will cause death or serious injury.
Qualified personnel only.
Disconnect and lock off all power before
working on this equipment.
• Always work on de-energized
equipment.
• Always de-energize before
performing any tests, maintenance,
or repair.
• Follow safety related work practices,
as described in NFPA 70E, at all times.
NOTICE
Erroneous test results may occur when the trip
unit is powered by either:
• Load current
• External 24 vdc control power
All testing should be conducted with the primary
bus de-energized, and external 24 vdc control
power disconnected or turned off.
Summary of Contents for WLTS
Page 7: ...7 Notes ...
