Precision Control Systems 3629C - Manual (Page 24)

MODEL 3629C 20 04/10/2007
TROUBLESHOOTING
CAUTION:
High Voltage exists on controller, circuit board, and other equipment located near the
controller. Use extreme caution to avoid electrical shock. Except for voltage and current
measurements, remove power before attempting to service this equipment.
Electrical measurements should be made by qualified personnel only.
NOTES
Control Concepts has field service engineers who can
help to determine the cause of controller problems. Please
call (952) 474-6200 with any questions you may have.
Because of critical assembly requirements
on controllers rated 200 Amps or more, it is
recommended that the controller be sent to the
factory for SCR replacement.
When using average feedback you will get more accurate
results if you make your measurements with an average
responding meter. For accurate readings when using
RMS feedback, use only a true RMS responding meter.
The controller must have a load capable of drawing at
least 1 amp to operate properly. A circuit board with
the exact same specifications may be substituted for a
questionable circuit to help identify the location of the
problem.
When replacing circuit boards, do not remove wires
from the plug-in connector.
SYMPTOMS POSSIBLE CAUSES
ZERO LOAD POWER.
'LINE OK' LED IS NOT ON:
PHASE MISSING AT LINE INPUT.
Check for line voltage at the line terminals.
CIRCUIT FUSE CLEARED.
Any transformer fuses, when cleared, will cause a loss of
power to the firing circuit and will disable the controller.
THERMOSTAT OPEN.
The thermostat monitors heatsink temperature. When the
heatsink temperature rises above 87C, the thermostat will
disable the controller.
POOR CONNECTIONS.
Determine that the frame wiring connectors are plugged
fully onto the circuit board connectors.
ZERO LOAD POWER.
'LINE OK' LED IS ON:
Determine that a command (set point) signal is present
between the CCW and W terminals on the command
signal connector.
INCORRECT COMMAND WIRING.
On new installations, check all command wiring and
confirm that polarities are correct.
OVER CURRENT TRIP HAS OCCURRED.
If the O.C.T. LED is lighted, an over current trip has
caused the unit to shut down. Close the O.C.T. reset
switch or remove power temporarily to reset.
CLOSED O.C.T. RESET SWITCH.
If a remote over current trip reset switch is used, check
that the switch is open. If a remote switch is not used,
check that the voltage on terminal 9 is at least 10 Volts
with respect to terminal 10.