Bard WH381 Installation Instructions Manual

Manual 2100-342IPage 17 of 24START UPIMPORTANT INSTALLER NOTEFor improved start up performance wash the indoor coilwith a dish washing detergent.CRANKCASE HEATERSWH491-B and -C are provided with compressorcrankcase heat. All other models are not provided withcrankcase heat. They are either single phase or thesystem refrigerant charge is not of sufficient quantity torequire crankcase heat.The WH491-B and -C models have a wrap around typeheater located on the lower section of the compressorhousing. This is an on/off heater that is controlled bythe compressor contactor.The label in Figure 13 is affixed to all WH491-B and -Cunits detailing start up procedure. This is veryimportant. Please read carefully.HIGH PRESSURE SWITCHAll 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.TWO SPEED OUTDOOR FAN MOTORSAll units have two speed outdoor fan motors.The two speed outdoor fan motor is controlled with anoutdoor thermostat and operates on low speed below80° F outdoor temperature in cooling mode. In heatingmode it operates on high speed only.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 units incorporate a phase monitor to ensure properfield wiring. See the “Phase Monitor” section later inthis manual.Verification of proper rotation must be made any time acompressor is changed or rewired. If improper rotationis corrected at this time there will be no negative impacton the durability of the compressor.FIGURE 13START UP LABELHowever, reverse operation for over one hour may havea negative impact on the bearing due to oil pump out.NOTE: If compressor is allowed to run in reverserotation for several minutes, the compressor’sinternal protector will trip.All three phase ZR3 compressors are wired identicallyinternally. 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 tabulate values.The direction of rotation of the compressor may bechanged by reversing any two line connections to theunit.7961-411IMPORTANTTHESE PROCEDURES MUST BEFOLLOWED AT INITIAL START UPAND AT ANY TIME POWER HASBEEN REMOVED FOR 12 HOURSOR LONGER.To prevent compressor damage whichmay result from the presence of liquidrefrigerant in the compressor crankcase:1. Make certain the room thermostat is inthe “off” position. (The compressor isnot to operate.)2. Apply power by closing the systemdisconnect switch. This energizes thecompressor heater which evaporatesthe liquid refrigerant in the crankcase.3. Allow 4 hours or 60 minutes per poundof refrigerant in the system as notedon the unit rating plate, whichever isgreater.4. After proper elapsed time thethermostat may be set to operate thecompressor.5. Except as required for safety whileservicing, do not open systemdisconnect switch.