Bard WH422D Installation Instructions Manual

Manual 2100-443Page 15START UPIMPORTANT INSTALLER NOTEFor improved start-up performance, wash the indoorcoil with a dishwashing detergent.CRANKCASE HEATERSWH422 units are provided with compressor crankcaseheat. WH484 and WH603 units are not provided withcrankcase heat. These units utilize scroll compressorswhich do not require crankcase heat in this application.The WH422 models have an insertion well-type heaterlocated in the lower section of the compressor housingthis is a self-regulating type heater that draws onlyenough power to maintain the compressor at a safetemperature on these units.Some form of crankcase heat is essential to preventliquid refrigerant from migrating to the compressor,causing oil pump out on compressor start-up andpossible valve failure due to compressing a liquid.The decal in Figure 10 is affixed to all WH422 unitsdetailing start-up procedure. This is very important.Please read carefully.HIGH PRESSURE SWITCHThe models are supplied with a remote reset highpressure switch. If tripped, this pressure switch may bereset by turning the thermostat off then back on again.THREE PHASE SCROLL COMPRESSORSTART UP INFORMATIONScroll compressors, like several other types ofcompressors, will only compress in one rotationaldirection. Direction of rotation is not an issue withsingle phase compressors since they will always startand run in the proper direction.However, three phase compressors will rotate in eitherdirection depending upon phasing of the power. Sincethere is a 50-50 chance of connecting power in such away as to cause rotation in the reverse direction,verification of proper rotation must be made. All threephase scroll units incorporate a phase monitor to ensureproper field wiring. See the Phase Monitor" on page 15of this manual.Verification of proper rotation must be made any timea compressor is change or rewired. If improper rotationis corrected at this time there will be no negative impacton the durability of the compressor. However, reverseoperation for over one hour may have a negative impacton the bearing due to oil pump out.FIGURE 10START UP LABELIMPORTANTTHESE PROCEDURES MUST BE FOL-LOWED AT INITIAL START UP AND ATANY TIME POWER HAS BEEN REMOVEDFOR 12 HOURS OR LONGER.TO PREVENT COMPRESSOR DAMAGE WHICHMAY RESULT FROM THE PRESENCE OF LIQ-UID REFRIGERANT IN THE COMPRESSORCRANKCASE:1. MAKE CERTAIN THE ROOM THERMOSTAT ISIN THE “OFF“ POSITION. (THE COMPRESSORIS NOT TO OPERATE.)2. APPLY POWER BY CLOSING THE SYSTEMDISCONNECT SWITCH. THIS ENERGIZES THECOMPRESSOR HEATER WHICH EVAPO-RATES THE LIQUID REFRIGERANT IN THECRANKCASE.3. ALLOW 4 HOURS OR 60 MINUTES PERPOUND OF REFRIGERANT IN THE SYSTEM ASNOTED ON THE UNIT RATING PLATE, WHICH-EVER IS GREATER.4. AFTER PROPER ELAPSED TIME THE THER-MOSTAT MAY BE SET TO OPERATE THE COM-PRESSOR.5. EXCEPT AS REQUIRED FOR SAFETY WHILESERVICING, DO NOT OPEN SYSTEM DISCON-NECT SWITCH. 7961-411NOTE: If compressor is allowed to run in reverserotation for several minutes, the compressor'sinternal protector will trip.All three phase ZR3 compressors are wired identicalinternally. As a result, once the correct phasing isdetermined for a specific system or installation,connecting properly phased power leads to the sameFusite terminal should maintain proper rotationdirection.Verification of proper rotation direction is made byobserving that suction pressure drops and dischargepressure rises when the compressor is energized.Reverse rotation also results in an elevated sound levelover that with correct rotations, as well as, substantiallyreduced current draw compared to tabulated values.The direction of rotation of the compressor may bechanged by reversing any two line connections to theunit.