SECTION
6-
Testing and Troubleshooting
6.1-General lnformation
Once the breaker has been converted and before it is ener
gized, it must be tested as described in Section 6.2 . If any
problems develop with the trip device system, refer to Sec
tion 6.3 and Section 6.4 for troubleshooting details.
6.2-Testing
Before installing a converted breaker back into service,
perform the following steps:
1. Verify that the programmer is securely installed. The
phase sensors MUST NOT be energized if they are open
circuited.
2 . Megger breaker primary circuit using a 1 ,000-Volt
Megger.
3. Check the trip device system by either of two
methods:
2 4
A. Conduct high-current, single-phase tests on the
breaker using a high current-low voltage test set.
NOTE:
For these single-phase tests, special con
nections must be employed for MicroVersaTriprM
breakers equipped with Ground Fault. Any single
phase input to the programmer circuit will gener
ate an unwanted "ground fault" output signal
which will trip the breaker. This can be nullified
either by
1. Testing two poles of the breaker in series,
or
2 . Using the Ground Fault Defeat Cable as
shown in Fig. 6-5. This special test cable ener
gizes the programmer circuit in a self-cancelling,
series-parallel connection so that its output is
always zero.
Compare results with the applicable time-current
characteristic curves given in Fig. 6-9 and
Fig. 6-10.
B. Test the components of the MicroVersaTrip™
system using portable Test Set Type TVTS1.
The applicable test procedures are detailed in
Instruction Book GEK-64464.
6.3-Troubleshooting
When malfunctioning is suspected, the first step in trouble
shooting is to examine the circuit breaker and its power
system for abnormal conditions such as:
1. Breaker tripping in proper response to overcurrents
or incipient ground faults.
2. Breaker remaining in a trip-free state due to mechani
cal interference along its trip shaft.
3. Inadvertent shunt trip activations.
WARNING:
DO NOT CHANGE TAPS ON THE
CURRENT SENSORS OR ADJUST THE PRO
GRAMMER UNIT SET KNOBS WHILE THE
BREAKER IS CARRYING CURRENT.
Once it has been established that the circuit breaker can be
opened and closed normally from the test position, attention
can be directed to the trip device proper. Testing is per
formed as described in Section 6.1, Step 2.
6.3.1-Resistance Values
For use in troubleshooting the MicroVersaTrip™ current
sensors, the resistance of the windings is given in Table 6-1.
Table 6-1-Current Sensor
Resistance
Breaker
Ampere
Resistance in Ohms
Frame
Between Common
Size
Tap
and Tap Terminals
300
20-24
400
27-32
600
42-50
AK-50
800
58-68
AKS-50
600
42-50
800
58-68
1200
93-109
1600
130-154
800
74-88
AKT-50
1200
116-136
AKST-50
1600
162-190
2000
210-246
1200
20-24
AK-75
1600
28-34
AKR-75
2000
37-44
3000
61-72
1600
36-43
AK-100
2000
47-55
AKR-100
3000
75-88
4000
108-127
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