GE Industrial Solutions EntelliGuard TU Trip Units - Manual (Page 70)

EntelliGuard TU Trip Units: UL/ANSI Models DEH-4567B
Maintenance and Troubleshooting
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TROUBLESHOOTING GUIDE
Table 11-1: Troubleshooting Guide
Error Potential Cause of Error Possible Solution
The trip unit display is blank or
backlight is intermittent. External +24 VDC is absent or
dipping below 22 VDC.
The load current fluctuates near
20% of the breaker sensor rating.
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.
The battery power supply is disabled when any
current is sensed through the current sensors.
Check that the control power supply is present and
operational.
The trip unit displays E02. BIM error. No communication with the BIM
Check the BIM harness.
Mismatch trip unit / BIM option.
The trip unit displays E03. Memory failure. Return the unit to GE.
The trip unit displays E06. Internal failure. Return the unit to GE.
The trip unit displays E08. Invalid rating plug. Check the rating plug. The rating plug value shall
not exceed and be below 40% of the breaker
sensor.
Ensure the rating plug is properly sited.
Unit does not communicate
with the Master. The communication wires are
shorted or improperly connected.
Incorrect baud rate.
Incorrect address.
Locate and repair the short or the incorrect
connection.
Check that the baud rate assigned to the trip unit,
agrees with the baud rate at the host.
Check that the address assigned to the trip unit,
agrees with the address at the host.
Current readings are incorrect. Incorrect rating plug value. Check the rating plug label.
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 set trip unit PT to this value.
Set the trip unit phase to phase PH-PH or phase to
neutral PH-N according to the system.
The display is blank or the Low
Battery symbol appears when
the BATTERY key is pressed.
Line current is below 20% of the
breaker sensor rating.
The battery is discharged.
The battery was stored too long with
no power applied to the trip unit.
Replace the battery.
Power the trip unit with external power or by
energizing the breaker for several days to freshen
the battery.
Modbus communication is
intermittent or frequent
timeouts If trip unit is on the metering screen,
the metering calculations take
precedence over Modbus
communications and can create a
conflict Ensure trip unit is not displaying metering screen.