Bard QA241D Installation Instructions Manual

Bard QA241D Installation Instructions Manual Manual pdf 22 page image

Manual 2100-438Page 20START 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. High and low pressureswitch monitoring and alarm functions.Service LightsOne service light indicates when service is required.ï Check System ñ detects high or low pressureswitch operation for compressor protection.OPTIONAL CFM (QA361, QA421, QA481AND QA601 ONLY)These units are shipped from the factory set to operate atthe optional CFM level shown in Table 8. This provideslower operating sound levels for non-ducted, freedischarge applications. This CFM level will reduce thesystem capacity performance by approximately 2% atthe 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 a pinkjumper wire with both ends attached to terminalmarked ìG2î. Move one end of this jumper toterminal ìYî.5. Reverse steps to reassemble.IMPORTANT INSTALLER NOTEFor improved start-up performance, wash the indoor coilwith a dishwasher detergent.This unit is equipped with a variable speed ECM motor.The motor is designed to maintain rated airflow up tothe maximum Static allowed. It is important that theblower motor plugs are not plugged in or unpluggedwhile the power is on. Failure to remove power priorto unplugging or plugging in the motor could result inmotor failure.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 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 oven one hour mayhave a negative impact on the bearing due to oil pumpout.CAUTIONDo not plug in or unplug blower motorconnectors while the power is on. Failure todo so may result in motor failure.