SECTION 1 2- MicroVersaTrip™ Trip Device (Cont.}
1 2.3
FLUX SHIFTER TRIP DEVICE
The only difference between the MicroVersaTrip and
SST flux shifter trip devices is the solenoid winding. Refer
to Section 1 0.3 for details.
When replacing a M icroVersaTrip flux shifter, AM P ex
traction tool Cat. No. 455822-2 is required to remove the
socket leads from the AM P connector.
1 2.4 TROUBLESHOOTING
When malfunctionion is suspected, the first step in
troubleshooting is to examine the circuit breaker and its
power system for abnormal conditions such as:
a) Breaker tripping in proper response to overcurrents or
incipient ground faults.
b) Breaker remaining in a trip-free state due to
mechanical maintenance along its trip shaft.
c) Inadvertent shunt trip activations.
WARNING:
DO NOT CHANGE TAPS ON THE CUR
RENT SENSORS OR ADJUST THE PROGRAMMER
UNIT SET KNOBS WHILE THE BREAKER IS CAR
RYING CURRENT.
64
FIG. 87A - MICROVERSATRIP®
COMPONENT WITH TAPPED SENSORS
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 performed by either of two methods:
1 . Conduct high-current, single-phase tests on the
breaker using a high current-low voltage test set.
NOTE:
For these single-phase tests, special connec
tions must be employed for Micro Versa Trip breakers
equipped with Ground Fault. Any single-phase input
to the programmer circuit will generate an unwanted
"ground fault" output signal which will trip the
breaker. This can be nullified either
by
a) Using the Ground Fault Defeat Cable as shown in
Fig.
93.
This special test cable energizes the pro
grammer circuit in a self-cancelling, series-parallel
connection so that its output is always zero.
2. Test the components of the MicroVersaTrip system
using portable Test Set Type TVTS1 (Fig.
88).
The ap
plicable test procedures are detailed in instruction Book
G EK-64464.
The time-current characteristics for the M icroVersaTrip
Trip Device are given in curves G ES-6195 and G ES-6199.
FIG. 878 - RMS-9, EPIC MICROVERSATRIP®
AND MVT -PLUS OR MVT -PM COMPONENTS
WITH FIXED SENSORS
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