Bard WA302 Installation Instructions Manual

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Bard WA302 Installation Instructions Manual Manual pdf 15 page image

Manual 2100-404Page 13IMPORTANT INSTALLER NOTEFor improved start-up performance, wash the indoorcoil with a dishwasher detergent.HIGH PRESSURE SWITCHThe WA372 models are supplied with a remote resethigh pressure switch. If tripped, this pressure switchmay be reset by turning the thermostat off then back onagain.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 in thismanual.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.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 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.START UPPHASE MONITORAll units with three phase compressors are equippedwith a 3 phase line monitor to prevent compressordamage due to phase reversal.The phase monitor in this unit is equipped with twoLEDs. If the Y signal is present at the phase monitorand phases are correct the green LED will light.If phases are reversed, the red fault LED will be lit andcompressor operation is inhibited.If a fault condition occurs, reverse two of the supplyleads to the unit. Do not reverse any of the unit factorywires as damage may occur.SERVICE HINTS1. Caution homeowner to maintain clean air filters at alltimes. Also, not to needlessly close off supply andreturn air registers. This reduces air flow through thesystem, which shortens equipment service life as wellas increasing operating costs.2. Check all power fuses or circuit breakers to be surethey are the correct rating.3. Periodic cleaning of the outdoor coil to permit fulland unrestricted airflow circulation is essential.SEQUENCE OF OPERATIONCooling—Circuit R-Y makes at thermostat pulling incompressor contactor, starting the compressor andoutdoor motor. The G (indoor motor) circuit isautomatically completed on any call for coolingoperation or can be energized by manual fan switch onsubbase for constant air circulation. On all 230 voltunits there is a one minute off delay on the blowermotor. 460 volt models do not have an off delay. On acall for heating, circuit R-W1 make at the thermostatpulling in heat contact for the strip heat and bloweroperation. On a call for second stage heat, R-W2 makesbringing on second heat contactor, if so equipped.The direction of rotation of the compressor may bechanged by reversing any two line connections to theunit.