ADC AD-464 Service Manual

ADC AD-464 Service Manual Manual pdf 48 page image

44SECTION VIPLC (PROGRAMMABLE LOGIC CONTROLLER) SYSTEMA. PLC (Programmable Logic Controller) DESCRIPTIONThe heart of the dryer is a TSX17 PLC (Programmable Logic Controller) with twenty-one (21) inputs and twelve(12) outputs. The TSX17 PLC also uses two (2) expansion modules, a relay output module with six (6) outputs,and a 4 mA - 20 mA (milliamphere) analog input module with four (4) inputs. The operator interface for theTSX17 PLC is the XBT digital display unit.The TSX17 PLC's (Programmable Logic Controller's) main module zero ("0") inputs are as follows:• The "0" is used to sense that the 110 VAC control voltage has been turned on via the master control relay. Ifthe master control failed to be turned on, the XBT unit will display "CNTRL VOLT OFF" (control voltageoff).• Input 1 monitors the overloads (OL) for motors OL1, OL2, OL3, OL4, and on gas dryers OL8. The over-loads have auxiliary contacts in them that are tied in series from the control voltage to Input 0,1. In acase that an overload trips, the XBT unit will display a "motor fault."• Input 0,2 is used to monitor that the burner fan is on during a heat cycle. (This is not used on steam dryersand is tied to Input 0,10 on steam dryers.) In a case were there is a call for heat and the burner fandoes not turn on, the dryer will display a "heater fault."• Input 0,3 main function is to sense if one (1) of the high limits have tripped due to excessively hightemperature in the dryer. If the high limit trips, the XBT unit will display "HI-TEMP FAULT."• Input 0,4 monitors the gas pressure. If a high gas pressure or a low gas pressure situation arises, voltage isremoved from Input 0,4 causing a heat cycle to be discontinued and a "GAS SUPPLY FAULT" tobe displayed. On steam models, this input is tied to the PLC's (Programmable Logic Controller's)110 VAC power source.• Input 0,5 is used to sense a clogged lint screen or obstruction in the exhaust via an air switch that is located inthe lint collection area. A fault in the air flow produces an "AIR FLOW FAULT" message.• Input 0,6 is used to monitor the front load door if this load door is closed by means of DS1, A (Door Switch 1,A contacts). A drying cycle will not begin until Input 0,6 is on. If a cycle is started and the door isopen, the XBT unit will display "DOOR OPEN."• Input 0,7 monitors the rear door via the DS2, A (Door Switch 2, A) contacts. A cycle cannot be begin untilthe doors are closed. If a cycle is started with the rear door open, the XBT unit will display "DOOROPEN." in the case of one (1) door dryer, Input 0,7 is tied to 110 VAC.• Input 0,8 is used to monitor the two (2) lint drawers. This is achieved through two (2) proximity switches, onefor each lint drawer. There is a magnet on each of the lint drawers, which when aligned with theproximity switch causes a contact closure which brings 110 VAC to Input 0,8. When a cycle isstarted and a lint drawer is not closed, the XBT unit will display "CHK. LINT DRAWER" (checklint drawer).