Carrier 50PG20-28 Controls, Start-up, Operation, Service And Troubleshooting Instructions

Also see for 48PG20---28: User's information manual User's information manual Installation and service instructions

Carrier 50PG20-28 Controls, Start-up, Operation, Service And Troubleshooting Instructions Manual pdf 88 page image

Evaporator Fan Belt Tension Adjustment -- Toadjust belt tension:1. Turn offunit power.2. Slide out fan deck to service position as shown in Evapo-rator Fan Service and Replacement section above.3. Loosen tan motor bolts.4. Move motor mounting plate to adjust to proper belt ten-sion. See Table 57. Motor adjuster bolts may be used totighten belts. See Fig. 38.5. Check for proper belt aligmnent. Adjust if necessary.6. Tighten motor mounting plate bolts to lock motor inproper position.7. Return tan deck back into operating position.8. Restore power to unit.Condenser-Fan Adjustment (Fig. 40)1. Shut off unit power supply.2. Relnove coMenser-fan assembly (gille, motor, motorcover, and tan) and loosen tan hub setscrews.3. Adjust tan height as sho,an in Fig. 40.4. Tighten setscrews and replace condenser4hn asselnbly.5. Turn on power to unit.Fig. 40 -- Condenser-Fan AdjustmentVerify Sensor Performance -- Verit) that thermistor,transducer, and switch inputs (see Tables 50-52) are readingcorrectly. These values can be accessed through the ScrollingMarquee display in the Temperatures, Pressures, and Inputsmenus. Some values will depend on configuration choices.Refer to the Control Set Up Checklist completed for thespecific unit installation and to the configuration tables inAppendix A.Economizer Operation During Power Fail-ure -- Dampers have a spring return. In event of power fail-ure, dalnpers will return to fully closed position until power isrestored. Do not mamtally operate damper motol:Evacuation -- Proper evacuation of the system will re-move noncondensables and ensure a tight, dry system beforecharging. Evacuate fiom both high and low side ports. Neveruse the system compressor as a vacuum pump. Refiigeranttubes and indoor coil should be evacuated to 500 microns.Always break a vacuum with dry nitrogen. The _vo possiblemethods are the deep vacuum method and the triple evacuationmethod.DEEP VACI__YMMETHOD The deep vacuum methodrequires a vacumn pump capable of pulling a minilnum vacu-um of 500 microns and a vacuum gage capable of accuratelymeasuring this vacuum depth. The deep vacuum method is themost positive way of assuring a system is fiee of air and liquidwater. (See Fig. 41 .)Table 57 -- Belt Tension AdjustmentBELT TENSION (Ib)48PG VOLTAGE Unit Model Number Position 10A,J B,K C,L D,M E,N F,P G,Q H,R230 4.8 5.1 5.6 4.5 NA 4.7 5.0 5.520 460 4.8 5.1 5.6 4.5 NA 4.7 5.0 5.5575 5.3 5.1 5.6 4.5 NA 5.2 5.0 5.5230 4.8 5.1 5.6 4.5 NA 4.7 5.0 5.524 460 4.8 5.1 5.6 4.5 NA 4.7 5.0 5.5575 5.3 5.1 5.6 4.5 NA 5.2 5.0 5.5230 4.5 5.4 5.9 4.5 4.5 5.4 5.9 4.528 460 4.5 5.4 5.9 4.5 4.5 5.4 5.9 4.5575 4.5 5.4 5.9 4.5 4.5 5.4 5.9 4.5BELT TENSION (Ib)50PG VOLTAGE Unit Model Number Position 10A,J B,K C,L D,M E,N F,P G,Q H,R230 4.8 5.1 5.6 4.5 4.8 5.1 5.6 4.520 460 4.8 5.1 5.6 4.5 4.8 5.1 5.6 4.5575 5.3 5.1 5.6 4.5 5.3 5.1 5.6 4.5230 4.8 5.1 5.6 4.5 4.8 5.1 5.6 4.524 460 4.8 5.1 5.6 4.5 4.8 5.1 5.6 4.5575 5.3 5.1 5.6 4.5 5.3 5.1 5.6 4.5230 4.5 5.4 5.9 4.5 4.5 5.4 5.9 4.528 460 4.5 5.4 5.9 4.5 4.5 5.4 5.9 4.5575 4.5 5.4 5.9 4.5 4.5 5.4 5.9 4.588