Bard WA4822 Installation Instructions Manual

Contents

Bard WA4822 Installation Instructions Manual Manual pdf 17 page image

Manual 2100-348Page 15START 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 with singlephase compressors since they will always start and run inthe 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 the timethe equipment is put into service. If improper rotation iscorrected at this time there will be no negative impact onthe 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 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.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. 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 pulling incompressor contactor, starting the compressor andoutdoor motor. The G (indoor motor) circuit isautomatically completed on any call for cooling operationor can be energized by manual fan switch on subbase ofconstant air circulation. On all 230 volt units there is aone minute off delay on the blower motor. 460 voltmodels do not have an off delay.COMPRESSOR CONTROL MODULEThe compressor control module is standard on the modelscovered by this manual. The compressor control is ananti-short cycle/lockout timer with high and low pressureswitch monitoring and alarm relay output.Adjustable Delay On Make And Break TimerOn initial power up or any time power is interrupted tothe unit the delay on make period begins which will be 2minutes plus 10% of the delay on break setting. Whenthe delay on make is complete and the high pressureswitch (and low pressure switch if employed) is closed,the compressor contactor is energized. Upon shutdownthe delay or break timer starts and prevents restart untilthe delay on break and delay on make periods haveexpired.During routine operation of the unit with no powerinterruptions the compressor will operate on demand withno delay.