Operating instructions

5
OPERATION
1) TURN ON THE MAIN DISCONNECT SWITCH.
2) PUSH THE RED HIGH LIMIT RESET PUSHBUTTON TO PULL IN THE
CONTACTOR AND PROVIDE LOAD POWER.
3) THE INDICATING TEMPERATURE CONTROL (IN ENCLOSURE DOOR)
SHOULD BE SET TO DESIRED PROCESS TEMPERATURE BY PRESSING
UP/DOWN ARROWS AND THEN PRESSING ENTER (HALF CIRCLE) KEY
(FACTORY SET TO 125°F).
4) THE HIGH LIMIT CONTROL (PROCESS TEMPERATURE SENSING) IN
THE PANEL, MOUNTED ON THE BACK PANEL UNDER THE MAIN
CONTROLLER TO THE LEFT SIDE, SENSES PROCESS TEMPERATURE
AND WILL DISCONNECT POWER TO THE HEATERS IF OVER
TEMPERATURE OCCURS. SETPOINT SHOULD BE APROXIMATELY 20°
TO 25°F ABOVE PROCESS TEMPERATURE. WHEN THE TEMPERATURE
RETURNS TO BELOW THE HIGH LIMIT SETPOINT THE POWER WILL
RETURNED TO THE HEATING CIRCUIT ALLOWING THE HEATERS TO
COME ON BUT THE RED HIGH LIMIT RESET PUSHBUTTON WILL BE
ILLUMINATED UNTIL MANUALLY RESET (INDICATING THAT THERE WAS
A HIGH LIMIT OCCURANCE). THE CAUSE OF THE MALFUNCTION
SHOULD BE INVESTIGATED AT ONCE. POSSIBLE REASONS ARE:
• Thermocouple failure on the main temperature controller (indicated by “no”
in the upper display of the controller).
• “Over Ranging” of the main temperature controller (indicated by “over” in
upper display).
• Temperature controller setting higher then Hi-Limit controller setting.
• Main temperature controller out of calibration.
• Hi-Limit controller out of calibration.
• Heater magnetic contactor locked in closed position because of “welded”
contacts or mechanical binding.