Bard WH301 Installation Instructions Manual

Also see for WH301: Specifications Installation instructions

Contents

Manual 2100-193Page 17IMPORTANT INSTALLER NOTEFor improved start-up performance, wash the indoorcoil with a dishwashing detergent.CRANKCASE HEATERSAll units are provided with some form of compressorcrankcase heat.All single and three phase models have an insertionwell-type heater located in the lower section of thecompressor housing. This is a self-regulating typeheater that draws only enough power to maintain thecompressor at a safe temperature.Some form of crankcase heat is essential to preventliquid refrigerant from migrating to the compressor,causing oil pump out on compressor start up andpossible valve failure due to compressing a liquid.The decal in Figure 9 is affixed to all outdoor unitsdetailing start up procedure. This is very important.Please read carefully.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. The heat pump wall thermostats perform multiplefunctions. Be sure that all function switches arecorrectly set for the desired operating mode beforetrying to diagnose any reported service problems.4. Check all power fuses or circuit breakers to be surethey are the correct rating.5. 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 for constant air circulation.START UPHEATING – A 24V solenoid coil on reversing valvecontrols heating cycle operation. Two thermostatoptions, one allowing "Auto" changeover from cycle tocycle and the other constantly energizing solenoid coilduring heating season and thus eliminating pressureequalization noise except during defrost, are to be used.On "Auto" option, a circuit is completed from R-W1and R-Y on each heating "on" cycle, energizingreversing valve solenoid and pulling in compressorcontactor starting compressor and outdoor motor. R-Galso make starting indoor blower motor. Heat pumpheating cycle now in operation. The second option hasno "Auto" changeover position, but instead energizesthe reversing valve solenoid constantly whenever thesystem switch on subbase is placed in "Heat" position,the "B" terminal being constantly energized from R. Athermostat demand for heat completes R-Y circuitpulling in compressor contactor starting compressor andoutdoor motor.R-G make starting indoor blower motor.FIGURE 13START UP LABELIMPORTANTThese procedures must be followedat initial start up and at any timepower has been removed for 12hours or longer.To prevent compressor damage which mayresult from the presence of liquid refrigerant inthe compressor crankcase:1. Make certain the room thermostat is in the"off" position (the compressor is not tooperate).2. Apply power by closing the systemdisconnect switch. This energizes thecompressor heater which evaporates theliquid refrigerant in the crankcase.3. Allow 4 hours or 60 minutes per poind ofrefrigerant in the system as noted on theunit rating plate, whichever is greater.4. After properly elapsed time, the thermostatmay be set to operate the compressor.5. Except as required for safety whileservicing. Do not open systemdisconnect switch.7961-061