Bard Q-TEC Q24A2 Installation Instructions Manual

Contents

Bard Q-TEC Q24A2 Installation Instructions Manual Manual pdf 28 page image

Manual 2100-600Page 28 of 38START UPDESCRIPTION OF STANDARDEQUIPMENTHigh Pressure SwitchProvides refrigerant circuit high pressure protection.Includes lockout circuit that is resettable from roomthermostat.Compressor Control ModuleProvides short cycle protection for the compressorwhich extends compressor life, as well as high and lowpressure switch monitoring and alarm functions.Service LightsOne service light indicates when service is required.• Check System – detects high or low pressureswitch operation for compressor protection.OPTIONAL CFM (Q36A2, Q42A2, Q48A2AND Q60A2 ONLY)These units are shipped from the factory set to operateat the optional CFM level shown in Table 7. Thisprovides lower operating sound levels for non-ducted,free discharge applications. This CFM level will reducethe system capacity performance by approximately 2%at the same energy efficiency.Rated CFM is required for ducted applications formaximum performance rating. To obtain full CFM onthese models, connect jumper wire as follows:1. Disconnect all power to the unit. Failure to do somay result in damage to the motor.2. Open return air service panel3. Open inner control panel cover4. Locate low voltage terminal strip. There is apink jumper wire with both ends attached toterminal marked “G2”. Move one end of thisjumper to terminal “Y”.5. Reverse steps to reassemble.IMPORTANT INSTALLER NOTEFor improved start-up performance, wash the indoorcoil with a dishwasher detergent.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 and thecompressor contactor is allowed to energize.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.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 sucha way 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 rotationis corrected at this time there will be no negative impacton the durability of the compressor. However, reverseoperation for even one hour may have a negativeimpact on the bearing due to oil pump out.CAUTIONDo not plug in or unplug blower motorconnectors while the power is on.Failure to do so may result in motor failure.