Troubleshooting
18
3A1937C
Troubleshooting
Before performing any troubleshooting procedure:
1. Perform
Pressure Relief Procedure
found in vpm
Instructions manuals.
2. Turn main power OFF.
3. Allow equipment to cool.
Try the recommended solutions in the order given for
each problem, to avoid unnecessary repairs. Also,
determine that all circuit breakers, switches, and con-
trols are properly set and wiring is correct before assum-
ing there is a problem.
Common Problems
Problem
Cause
Verification
Solution
Heating is slow.
Heater defective.
Measure resistance of
heater.
Follow
Low power.
Measure voltage across cir-
cuit breakers. Voltage
should measure between
190 and 275 Vac.
1. If voltage is lower than
expected, use electrical
schematic to locate
faulty wiring or connec-
tion.
2. Have a qualified electri-
cian service electrical
components.
Heating over shoots.
Shorted module.
Verify for given zone that
temperature does not
increase when zone is dis-
abled.
Verify RTD wire or heater
power cord is attached to
correct heat module.
Replace module.