b)The expansion PLC (Programmable Logic Controller) module has eight (8) inputs which are labeled #10 through #17 and an six (6) output relays labeled #210 through #215.
(1)Input Relays
A fan on or off signal (input #10) determines if the dryer is operating. If the dryer is operating, the door function and tilt function shut down. Input #11 "HEATER FAULT RESET" monitors the "HEATER FAULT" reset
Input #14 indicates that the drying cycle is done (air jet signal). Once the output relay of the Phase 5 microprocessor controller (computer) turns on contact relay #4, input #14 is turned on. This in turn signals the PLC to illuminate the "END OF CYCLE" (E.O.C.) L.E.D. (light emitting diode) until the dryer is attended to.
Front door closed (input #15) is a safety circuit used to lock out the Phase 5 microprocessor controller (computer) from a drying cycle unless the doors are closed.
The front down/rear down (dryer level) is another safety device used so that a drying cycle cannot be initiated unless the dryer is in the level position.
(2)Output Relays
Output relay #210 controls the air supply to the top of the pneumatic piston to tilt the front of the dryer down.
Output relay #211 controls the air supply to the bottom of the pneumatic pistons to tilt the front of the dryer up, provided that the rear of the dryer is in the level position.
Output relay #212 controls the fan for the "HEATER FAULT" cool down routine and is controlled by microprocessor (computer) Pin #5.
Output relay #213 controls the air supply to the top of the pneumatic pistons to tilt the rear of the dryer down.
Output relay #214 controls the air supply to the bottom of the pneumatic pistons to tilt the rear of the dryer. Rear up (output relay #214) applies power to the S6 rear up solenoid through the front down level switch (LS1B).
The dryer "CLEAR/STOP" output (relay #215) is used to lock out the Phase 5 microprocessor (computer) from running a drying cycle. If the PLC (Programmable Logic Controller) has in- put #4 (front door open) and input #10 (blower [squirrel cage fan] on, or input #16 (lint door closed), input #15 (front door closed), or input #17 (dryer level) are off, then the PLC will close output relay #215 (dryer "CLEAR/STOP") so that a drying cycle cannot be initiated.
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