BGK AutoCure 5000, Assembly And Operating Manual

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13
Trouble Shooting Guide
Heater Power Problems
Problem
Heater lamps come on immediately when disconnect is closed.
Possible Cause and Corrective Action

With power OFF, measure the resistance from the lamp wires to ground. The measurement should be
more than 100 K ohms. If it is less than 100 K, check the lamp wiring and heater head for shorts to ground.
Check for a bad firing circuit board or a shorted SCR by: exchanging the firing circuit board with one from
a known good control. Does the problem follow the firing circuit board or does it stay with the SCR – replace
the defective component.

Contactor held closed – failed ON. Replace the contactor.
Problem
Heater lamps do not come on.
Possible Cause and Corrective Action

Is the Power On/Off button illuminated, is the temperature controller on? – Check that
incoming line power is present; transformer fuses, primary and secondary are good.

Do the contactors energize when the Cycle Start button is pressed? – Check for loose wires
associated with the contactors, change the temperature controller.

Check that the set point (bottom display) is higher than the process temperature (top
display).

Are the line fuses (FU 101 & 104) in front of the contactors good – check voltage on the load side of the
fuses or remove the fuses and check with an ohmmeter.

Is the green LED on the firing circuit lit? – Check that the firing circuit has 24 vac, with an ammeter
check that the 4-20ma input signal is present from the temperature controller. If the 4-20ma
signal is not present, see the section “No Output Signal from Temperature Controller”.

Do any of the zones function? – If the above points have been checked, confirm that there is a
complete circuit through the lamps and all wiring is tight – change the SCR.

Are all 3 zones dead? – Zone A should function regardless of the zone switch setting, there is only one firing
circuit for all zones - change the firing circuit
Temperature Controller Problems
Problem
Temperature controller has no display.
Possible Cause and Corrective Action
Check the supply voltage (24 VAC) to the unit at terminals 11 and 12. If voltage is present, replace the controller. If
voltage is not present, check source of power (fuses, transformers, wiring, etc.)