Troubleshooting I 6-25
6
Troubleshooting
Unit Faults
The Thermolator has detected a problem with the internal components, wiring, electrical power, or operat-
ing environment. Without correction, the fault could lead to equipment damage or personal injury if it is
not corrected.
• The controller displays an error code indicating the cause of the problem.
• The TCU may take automatic control actions, based on the nature of the fault, to best protect the op-
erator and the TCU until the fault is corrected.
• If the optional alarm package is installed, the fault strobe will illuminate and the audible alarm will
activate.
• Some faults require a power cycle to reset.
Fault Possible Cause Solution
Prr
E
Return Probe Fault Low
The “To Process” RTD is mal-
functioning or has a short circuit.
WARNING: Only qualified elec-
trical service personnel should
examine and correct problems
that require opening the unit’s
electrical enclosure or checking
electrical current.
u ALARM LED flashes in
conjunction with RETURN
LED.
u Optional strobe, sounder,
dry contacts actuated.
u Pump turns off.
u Heater turns off.
u Cooling valve closes.
This fault will automatically
reset when the problem is cor-
rected.
Do you have a break in your RTD
wiring?
Check the RTD loop wiring with a
VOM. See Checking the RTD.
Has the RTD itself failed or sus-
tained physical damage?
Test the RTD with a VOM. See
Checking the RTD.
If damaged, replace the RTD.
(Continued)