48049-251-01 M-frame Circuit Breakers
02/2006
© 2003–2006 Schneider Electric All Rights Reserved
9
ENGLISH
TESTING Circuit breaker trip unit operation can be tested using primary injection
testing or the full-function test kit.
NOTE: Older ET1.0 trip units have test port covered. Cut label as described
in full-function test kit instructions to access the trip unit port.
TROUBLESHOOTING If problems occur during installation, refer to information below. If trouble
persists, contact the field office.
OPERATION
Figure 16: Press Push-to-trip Button
Press push-to-trip button (A) at installation to
check operation. Repeat once a year to exercise
circuit breaker.
NOTE: Push-to-trip button will not trip circuit
breaker if it is in the off (O) position.
TRIP UNIT ADJUSTMENT
Adjust instantaneous trip (Ii) by adjusting switch
(A).
Figure 17: Adjust Instantaneous Trip Switch
06123226
A
setting
x In
4
5
6
7
10
3
2
Ii
Instantaneous
8
ET 1.0
06123231
06123091
A
DANGER
HAZARD OF ELECTRIC SHOCK,
EXPLOSION OR ARC FLASH
• Apply appropriate personal protective
equipment (PPE) and follow safe electrical
work practices. See NFPA 70E.
• This equipment must be installed and
serviced only by qualified electrical
personnel.
• Troubleshooting may require energizing
auxiliary devices with a test power supply.
Make sure that the power supply is off before
connecting or disconnecting it to the auxiliary
device.
• Do not touch the terminals of the device
during the test.
Failure to follow this instruction will result
in death or serious injury.
Condition Possible Causes Solution
Circuit breaker fails to stay
closed.
1. Trip adjustment set too low.
2. Undervoltage trip not
energized.
3. Shunt trip energized.
4. Short circuit or overload on
system.
1. Adjust trip setting.
2. Energize undervoltage trip.
3. De-energize shunt trip.
4. Check system for short
circuit or overload.
Circuit breaker trips, but no
short circuit or overload is
evident.
1. Trip adjustment set too low.
2. Voltage is below undervoltage
trip setting.
1. Adjust trip setting.
2. Check system for low
voltage.
Push-to-trip button will not
trip circuit breaker.
Circuit breaker already tripped or
off (O).
Move circuit breaker handle to
reset, then to on (I).
Circuit breaker cannot be
opened manually.
Damage to current path. Contact local field office.
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