51
High Ground/Earth Current Alarm
The following summarizes some of the possible causes and solutions for heat tracing
high ground current alarm.
Cause
Possible Solutions
Heat tracing is damaged.
Disconnect heat tracing circuit and
determine if alarm clears. If so, repair heat
tracing.
Wiring to heat tracing had high leakage
current.
Disconnect heat tracing and sequentially
disconnect power wiring until the alarm
ceases. Check last section removed for
damage.
Improper wiring of current sense wires
through torroid.
The current sensing toroid must have the
outgoing heater current lead and the return
current heater lead run through the toroid for
a proper ground leakage measurement. Redo
wire routing if only one wire has been run
through the current sensing toroid.
Heat tracing power wires in a multiple circuit
system improperly paired.
If the return current wire in the toroid is
from a different circuit the two heater
currents will not cancel and leave only leakage
to be measured. Correct wiring.
Heat tracing circuit has higher than
expected leakage due to circuit length or
higher voltage.
Replace the EPD breaker with a higher
ground/earth current trip device if
available. Where a controller (with variable
leakage trip functions) is doing the
ground/earth leakage detection function,
increase ground/earth leakage alarm set point
(if approved by project engineer).
If issues remain after exercising all these possible causes and solutions for heat
tracing alarms and trips, contact your nearest Thermon engineering center for
assistance and/or for arranging for field service.
