GE Industrial Solutions MicroVersaTrip Plus and MicroVersaTrip PM AK-25 and AKU-25 - Manual (Page 6)

6
SECTION 3 TESTING AND
TROUBLESHOOTING
Once the breaker has been converted, but before it
is energized, it must be tested. See below for
testing and troubleshooting details.
Testing
Before installing a converted breaker back into
service, perform the following steps:
Step 1.
Verify that the programmable trip unit is securely
installed by performing a continuity test on the CT
wiring and programmer. Disconnect the black CT
wires at each phase sensor. Then using a
continuity tester or V.O.M., check for continuity
from the white CT wire lead of the phase “A” CT
to the white CT wire lead of the phase “B” CT.
Repeat this continuity test for the white CT wire
leads of phase “A” and phase “C”. Next, measure
the resistance across each phase sensor and
compare the values measured to the values listed
in table 3-1. Be sure to reconnect the black CT
wire leads to all of the phase sensors prior to
performance testing the breaker.
CAUTION: In addition to the continuity test
described above and prior to performance test-
ing the converted breaker, each phase of the
breaker should be primary injected with a current
level of about 10% but no more than 20% of the
CT rating. During the application of test current,
the programmer’s screen should be activated by
depressing the battery button on its face and
check that the test current is displayed on the
screen for each phase tested. This test along
with the continuity test will confirm that no open
circuits exists in the CT harness and that the trip
unit is mounted properly. If the programmer
fails to display the test current, the test should be
stopped immediately and the programmer/wire
harness installation should be verified prior to
proceeding with any additional testing.
WARNING: IF THE CONVERTED BREAKER IS
ENERGIZED OR PRIMARY INJECTED USING A
SUFFICIENT LEVEL OF TEST CURRENT WITH A
LOOSE OR OPEN CIRCUIT BETWEEN THE CT’S
AND THE PROGRAMMER, DAMAGE WILL
OCCUR TO THE PROGRAMMER UNIT, WIRE
HARNESS, 36-PIN PROGRAMMER CONNECTOR
AND CT’S. FAILURE TO ADHERE TO THESE
INSTRUCTIONS WILL VOID ALL WARRANTIES.
Step 2.
Meggar the breaker primary circuit using a
1,000-Volt Meggar.
Step 3.
Measure the resistance across the line and load
terminals for each phase using a Micro-Ohmmeter
or Milli-Volt tester. If the resistance differs
considerably from phase to phase, the electrical
points may not be properly tightened. Also, it may
indicate improper contact wipe.
Step 4.
To verify that the breaker has been properly
retrofitted, a primary injection test should be
performed on each phase. This test will check the
CT’s, bus, wiring harness, flux shifter, and trip unit
as a complete system. A high current, low voltage
power supply should be connected across each
line and load terminal to simulate an overcurrent
fault. The long-time may be set at 0.5 to minimize
the breaker stress. When ground fault is installed,
the test can be performed by wiring two adjacent
poles in series or by using the GE test kit Cat. No.
TVRMS2. This will prevent the breaker from
tripping due to an unbalanced current flow.
Do not attempt to use GE test kit Cat. No.
TVTS1 or TVRMS on this programmer.
Troubleshooting
When malfunctioning is suspected, first 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
mechanical interference along its trip shaft.
3. Inadvertent shunt trip activation’s.
WARNING: DO NOT CHANGE TAPS ON THE
CURRENT SENSORS OR ADJUST THE
PROGRAMMER TRIP UNIT SETTINGS OR
REMOVE THE PROGRAMMER TRIP UNIT WHILE
THE BREAKER IS CARRYING CURRENT.
FAILURE TO ADHERE TO THESE INSTRUCTIONS
WILL VOID ALL WARRANTIES.