Troubleshooting; Disconnects - GE AK-2A-15 User Maintenance Manual

GEI-50299 Power Circuit Breakers Types
ALL E XCESS LUBRICANT S HOULD BE REMOVED
WITH A CLEAN CLOT H
ANY ACCUMULATION OF DIRT OR DUST.
At each maintenance period, all s ilver to
s ilver friction points, such as p r imar ydisconnects,
should be cleaned and g iven a fresh coat of G. E .
Spec. No. D50H4 7 lubr icant.
TROUBLE
Overheating
AK-2/3 Breakers
Failure to trip
AK-2 Breakers
False Tripping
AK-2 Breakers
Failure to Close and Latch
AK-2/3 BreaKers
False Tripping
AK-3 Breakers
Failure to Trip
AK-3 Breakers
6
AK-2-15 and AK-2/3-25
IN ORDER TO A V OID
CAUSE
Contacts not aligned
Contacts dirty, greasy or coated with dark
film
Contacts badly burned or pitted
Current carrying surfaces dirty
Corrosive atmosphere
Insuff i cient bus or cable capacity
Bolts and nuts at terminal connections
not tight
of
Current in excess breaker rating
Excessive ambient temperature
Travel of tripping device does not provide
of
positive release tripping latch
Worn or damaged trip unit parts
Bind in overcurrent trip device
Overcurrent trip device pick up too low
Overcurrent trip device time setting too short Check application
Bind in overcurrent trip device
�
Bin in attachments preventing resetting
of
late
of
Latch out adjustment
Latch return spring too weak or broken
Hardened or gummy lubricant
Closing solenoid burned out
Solenoid control device not functioning
properly
Captive Thump screw on Power Sensor
loose fail-safe circuitry reverts
to
characteristic minimum setting and
maximum time delay
Tap setting dial on Power Supply incorrectly
set
External Ground Sensor Coil improperly
connected
Loose or disconnected power sensor dis-
connect plugs
Loose or broken power sensor coil tap
connections
TROUBLES HOOTING
The following table l ists several typ ical s ymp­
toms of breaker malfunct ion, together with the ir
causes and remedies.
s ymptoms are observed, the ir cause should be
determined and the necessar y corrective action
should be taken.
REMEDY
Adjust contacts.
Clean contacts
Replace contacts
of
Clean surfaces current carrying parts
Relocate or provide adequate enclosure
of bus
Increase capacity
Tighten, but do not exceed elastic limit
bolts or fittings.
Check breaker application or modify circuit
by decreasing load
Provide adequate ventilation
Re-adjust or replace tripping device and
check mechanism latch adjustment
Replace trip unit
Replace overcurrent trip device
of
Check application
of
Replace overcurrent trip device
Re-align and adjust attachments
Adjust latch
Replace spring
Clean bearing and latch surfaces
Replace solenoid coil
Re-adjust or replace device
Tighten thumb screw on desired setting
dial to
Set correspond with Power Sensor coil
tap
to
Refer Figure 22, page 29 for polarity and
connections. Check continuity of shield and
conductors connecting the external Ground
Sensor coil.
Tighten or reconnect disconnect plugs
Tighten or reconnect tap connections
If, at any tim e, these
or cable
of
overcurrent trip device
overcurrent trip device