PMC MN-06001, Manual

Page: 26 / 66

PMCA-20
Manual
26
PROBLEM
Primary heater does not heat and the display on the controller shows ambient temperature.
SOLUTIONS
1. Check that the light on the OFF/ON switch is lit when the heater is turned on, if not
replace the switch.
If the light is on move to the next step.
1. Check the heater breaker in the main console, reset the breaker, if it continues to
trip, wrap an amp clamp around one of the wires coming off the breaker if it does
not exceed the rating of the breaker, the breaker needs to be replaced. If the
breaker draws more than its rating the most likely cause is that one or more of the
1250 watt fire rods is shorted. Remove the heater cover, disconnect the wires and
check each rod for resistance.
If the breaker is not tripped move on to the next step.
2. Open the console top and locate the solid state relay for the heater, looking over
the console top from the front of the machine, it is the relay to the left. With the
heater on and there is a LED light lit on the relay take a volt meter that is set on AC
volts and measure across position L1 and L2 (heavy wires). With the relay
functioning properly you should have a 1 volt reading, if you have a 208-230 volt
reading, the relay has malfunctioned and needs to be replaced. If the AC voltage
reads zero remove the pre-heater cover and look for loose or broken wires.
If there is no LED light on the solid state relay move to the next step.
3. With a DC volt meter read across position A1 and A2 on the solid state relay
(smaller wires) if you have a reading of 4-6 volts DC replace the solid state relay.
If there is no DC voltage to the relay move to the next step.
4. Using a DC volt meter measure across position 9 and 10 on the back of the heater
controller this is the output of the controller and sends power to the solid state
relay, your reading will be 4-6 volts DC if there is no reading check to make sure
that the set temperature of the controller is above the actual temperature reading
on the controller. Before replacing the controller read across position 1 and 2 to
make sure that the controller is powered up, your reading will be 208 to 230 volts
AC. If no voltage is present check for loose wires or a malfunction of the heater
circuit breaker.
If there is power in and out of the controller move to the next step.
5. Remove the heater top and check the over temperature limit switch for loose wires,
if the wires are secure take a continuity reading across the switch.
If the switch is open or has no continuity replace the switch.