GE Industrial Solutions WavePro Low-Voltage Power Circuit Breakers - Manual (Page 38)

MicroVersaTrip Plus™ and MicroVersaTrip PM™ Trip Units
Chapter 5. Maintenance and Trouble-Shooting
30
5-3 Trouble-Shooting Guide
The following guide is provided for trouble-shooting and
isolating common problems. It does not cover every possi-
ble condition. Contact the Customer Support Center at
800-843-3742 if the problem is not resolved by these pro-
cedures.
Symptom Possible Cause Corrective Action
1. The Trip Unit display is
blank.
Line current is below 20% of the
breaker sensor rating
(MicroVersaTrip Plus).
External +24 Vdc is absent
(MicroVersaTrip PM).
At least 20% of the current sensor rating, xCT, must be flowing
through the breaker to activate the display. If not, power the Trip
Unit with the internal battery or the Portable Power Pack. The
battery power supply is disabled when any current is sensed
through the current sensors.
Check that the auxiliary power supply is present and operational.
2. The Trip Unit display
flashes.
Can occur on Plus-style Trip Units
when the load current fluctuates near
20% of the breaker sensor rating.
Power the Trip Unit with the internal battery or the Portable
Power Pack.
3. The Trip Unit display flashes
ERR.
The built-in self test has detected an
error.
Replace the Trip Unit.
4. The trip indication target will
not clear.
Trip Unit is not in Status mode. Press FUNCTION until STATUS is displayed. Hold down the
VALUE key and press the SELECT key to clear the target.
5. Unit does not communicate
with the Modbus Monitor or
the Power Management
Control System
The communication wires are shorted
or improperly connected.
The Trip Unit address is incorrect.
Locate and repair the short or the incorrect connection.
Check that the address assigned to the Trip Unit, as in Chapter 2,
agrees with the address at the host.
6. Current readings are
incorrect.
The rating plug value was defined
incorrectly.
Read the X value from the rating plug name plate and enter this
as the xIn value with the rating plug current set point procedure
in Chapter 2. Do not enter the sensor rating, S.
7. Voltage readings are
incorrect.
The potential transformer (PT)
primary voltage was defined
incorrectly.
The PT connection was defined
incorrectly.
Read the PT primary rating from the PT name plate and enter this
value with the PT primary voltage procedure in Chapter 2.
Follow the PT connection procedure in Chapter 2 to enter Ph-N
for a wye-connected PT primary or Ph-Ph for a delta-connected
PT.
8. The display is blank or the
Low Battery symbol appears
when the BATTERY key is
pressed.
The battery is discharged. Replace the battery.