Bard WA4842 Installation Instructions Manual

Contents

Bard WA4842 Installation Instructions Manual Manual pdf 17 page image

Manual 2100-401APage 17 of 21START UPIMPORTANT INSTALLER NOTEFor improved start up performance wash the indoor coilwith a dish washing detergent.CRANKCASE HEATERSThese units are not provided with crankcase heat. Theseunits utilize scroll compressors which do not requirecrankcase heat in this application.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.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 rotation, as well as, substantiallyreduced current draw compared to tabulated values.Verification of proper rotation must be made at thetime the equipment is put into service. If improperrotation is corrected at this time, there will be nonegative impact on the durability of the compressor.However, 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 rotation direction.The direction of rotation of the compressor may bechanged by reversing any two line connections to theunit.PHASE MONITORAll units with three phase scroll compressors areequipped with a 3 phase line monitor to preventcompressor damage 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 atall times. Also, not to needlessly close off supplyand return air registers. This reduces airflow throughthe system, which shortens equipment service life aswell as increasing operating costs.2. Switching to heating cycle at 75° F or higher outsidetemperature may cause a nuisance trip of the remotereset high pressure switch. Turn thermostat off, thenon to reset the high pressure switch.3. Check all power fuses or circuit breakers to be surethey are the correct rating.4. Periodic cleaning of the outdoor coil to permit fulland unrestricted airflow circulation is essential.SEQUENCE OF OPERATIONCOOLING – Circuit R-Y makes at thermostat pullingin compressor 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 of constant air circulation. On all 230 volt unitsthere is a one minute off delay on the blower motor. 460volt models do not have an off delay.COMPRESSOR CONTROL MODULEThe compressor control module is standard on themodels covered by this manual. The compressor controlis an anti-short cycle/lockout timer with high and lowpressure switch monitoring and alarm relay output.