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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:
A. Conduct high-current, single-phase tests on the
breaker using a high current-low voltage test set.
For these single-phase tests, special con
NOTE:
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.
2 4
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.
DO NOT CHANGE TAPS ON THE
WARNING:
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
Frame
Tap
Size
300
400
600
800
AK-50
AKS-50
600
800
1200
1600
800
AKT-50
1200
AKST-50
1600
2000
1200
AK-75
1600
2000
AKR-75
3000
1600
2000
AK-100
AKR-100
3000
4000
Resistance in Ohms
Between Common
and Tap Terminals
20-24
27-32
42-50
58-68
42-50
58-68
93-109
130-154
74-88
116-136
162-190
210-246
20-24
28-34
37-44
61-72
36-43
47-5 5
75-88
108-127
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