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Hersteller: Carrier Dateigröße: 1.76 mb Dateiname: Unterrichtssprache:

SWITCH —o- SAFETY DEVICE CONTACTS,N.C Ï_1 "m'Iaux ■* TCONTACTS,NOJ •—#—J PUMPOUT RELAY p POR CONTACTS.NO. TR TR CONTACTS,N.O. -#- a2 LIQ SOL VALVE A|o_ a a a ■o —I I HIGH PRESS SWITCH TIMER RELAY B2 ! COND AUX AUX CONTACTS,N.O. —°—s|f—Ç) COMPRESSOR CONTACTS.N.O. 1. Starting Sequence (Assuming evaporator interlocks and all operating safety controls are in closed position) Time: 0 Min 0 Sec - Timer switch plunger is up at beginning edge of cam node and contacts are in positions A-A2 and B-B2, as shown.* Control thermostat closes, energizing liquid line solenoid valve (SV) and pump-out relay (POR). POR N.O. contacts close. Re- B| (Ô TIMER MOTOR CAM 1/5 RPM, 15 SEC CAM NODE o TIMER MOTOR frigerant pressure rises and low-pressure switch closes. Condenser auxiliaries, such as condenser water pump, tower fan, etc., start and their auxiliary starter contacts close. Timer relay (TR) is energized thru timer switch contacts A-A2, closing TR N.O. contacts and opening TR N.C. contacts. Timer motor (TM) is energized thru timer switch contacts B-B2 and starts running. * This is the position always reached by the cam each time after the compressor has stopped and the timer motor has completed its 4 min and 45 sec timing run. Starting Sequence of Time Guard Control (Single Pump-Out Arrangement Shown) 21 06D,07D INSTALLATION Carrier ■L| EVAPORATOR INTERLOCK CONTACTS,N.O. - OFF - LOW PRESS. SWITCH CONTROL THERMOSTAT -- SAFETY DEVICE CONTACTS,N.C. -4f- M" AUX ]/__ CONTACTS,N.O; POR CONTACTS.N.O. TR COND AUX PUMPOUT RELAY TR CONTACTS.N.O. - LIQ SOL VALVE CONTACTS,N.C. 2. Operating Condition Time: 0 Min 15 Sec Timer switch plunger has dropped off the cam node and the contacts have switched to positions A-Ai and B-Bi. Timer motor stops running since TR N.C. contacts are open. O- o- o ■o —ÏTJ-O—I» HIGH PRESS,. SWITCH TIMER RELAY COND AUX AUX CONTACTS.NO. *—4/h— COMPRESSOR TIMER MOTOR CAM 1/5 RPM, 15 SEC CAM NODE O TIMER MOTOR Timer relay (TR) remains energized thru TR N.O. contacts, which are now closed. Compressor motor starter is energized thru timer switch contacts A-A\ and compressor starts. Compressor continues to run unless circuit is broken by action of control thermostat or safety devices. Operating Condition of Time Guard Control (Single Pump-Out Arrangement Shown) CONTACTS, N.C. TIMER MOTOR CAM 1/5 RPM, 15 SEC CAM NODE 3. Stopping Sequence Time: Any time after 15 seconds Timer switch plunger is still in position of having just dropped off the cam node, since timer motor has not been running, and switch contacts are in position A-Ai and B-Bi. Thermostat opens when cooling load is satisfied. Liquid solenoid valve (SV) is deenergized and closes. Pumpout relay (POR) is de-energized, and its contacts open. The timer relay (TR) and compressor continue to operate thru compressor starter auxiliary contacts "M" until system pumps down and low-pressure switch opens. Then compres- sor and condenser auxiliaries stop and relay TR is de-energized. TR N.C. contacts close and timer motor (TM) is energized thru switch contacts B-Bi and starts to run. The TM timer will switch again to position A-A2 and B-B2 after 4 min 45 sec elapse. Thus, at least 4 min 45 sec must elapse after a shutdown before the compressor can begin its restart sequence, if the cooling thermostat is closed. A total of 5 min will elapse before the compressor can restart. Each compressor restart is preceded by 15 sec operation of the condensing equipment. This reverts to conditions at time 0 min 0 sec. Stopping Sequence of Time Guard Control (Single Pump-Out Arrangement Shown) 22 (Carrier) INSTALLATION 06D,07D Shut-Off Valves The suction and discharge shut-off valves are of the backseating type and have gage ports. Frontseating the valve closes the refrigerant line and opens the gage port to the pressure in the compressor. Backseating the valve shuts off pressure to the gage port. To attach a gage or charging line to the gage port, backseat the valve to prevent escape of refrigerant. U se a square ratchet or box-end wrench to open or close a valve. Do not use pliers or an adjustable wrench. They are likely to round the valve stem. Do not use excessive force to turn the stem. If it turns hard, loosen the packing gland nut. If the valve sticks on its seat, a sharp rap on the wrench will usually break it loose. Crankcase Heater The crankcase heater is an internal cartridge-type heater that is inserted in a blind hole in the compressor bottom cover. It does not come in direct contact with the oil. The heater draws 75 watts and is held in the hole by a clip. Insure that the crankcase is held tightly in place by the clip. The heater is approved for wet locations. The crankcase heater should be energized at least 12 hours before start-up to insure that the refrigerant is out of the oil. Liquid Line Solenoid Valve (Field Supplied) The purpose of this valve is to prevent...

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