Alfa Laval Heatpac EHS-71, System Instructions

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6 Alarms and Fault Finding
6.1 Alarm Indication
A fault in the Heatpac
®
EHS-71 heating system
is normally indicated by an activated alarm in
the control unit. Below is a list of possible alarm
causes and remedies.
Causes Corrective action
High temperature
Alarm limit for high temp. too low. Adjust parameter for high temperature limit.
Flow irregularities or abnormal input conditions. Check oil flow and inlet temperature. Adjust
process condition.
Faulty triac module(s) in the power unit.
Check the Triacs. Replace if necessary.
Broken wiring or defective heater resistance. Check wiring and heater resistance of each block
or heater element. See EHM heater component
booklet.
Low temperature
Alarm limit for low temp. too high. Adjust parameter for low temperature limit.
Flow irregularities or abnormal input conditions. Check oil flow and inlet temperature. Adjust
process condition.
Broken fuses or burned contactors. Find the cause of the broken fuse and remedy.
Renew broken fuses.
Check wiring and contactor coils.
Faulty controller in the control unit. Check the control unit and the electric heater kit.
Clogged heater element.
Dismantle the heater and check for clogged
element. Clean the heater elements in suitable
solvents.
Broken wiring or defective heater resistance. Check wiring and heater resistance of each block
or heater element. See EHM heater component
booklet.
Safety function released
Temperature switch tripped Check temperature setpoint in the control unit.
Reset temperature switch and restart heater.
Oil pump stopped Check piping and restart the oil pump and heater.
Broken temperature switch Check the temperature switch for broken circuit,
Replace if broken. Readjust. See Temperature
switch component booklet.
Broken wiring or faulty controller in the control
unit. Check wiring in the power unit and temperature
switch circuits.
If wiring OK:
Replace the control module in the control unit.
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