Carrier 50YDV Installation, Operation And Maintenance Instructions

Carrier 50YDV Installation, Operation And Maintenance Instructions Manual pdf 46 page image

R e s i d e n t i a l P a c k a g e d U n i t s - 6 0 H z P u r o n ®R e v. : 4 J a n . , 2 0 1 246Functional TroubleshootingPerformance Troubleshooting Htg Clg Possible Cause SolutionInsufficient capacity/ Notcooling or heatingX X Dirty filter Replace or clean.X Reduced or no air flow in heatingCheck for dirty air filter and clean or replace.Check fan motor operation and airflow restrictions.Too high of external static. Check static vs. blower table.X Reduced or no air flow in coolingCheck for dirty air filter and clean or replace.Check fan motor operation and airflow restrictions.Too high of external static. Check static vs. blower table.X X Leaky duct work Check supply and return air temperatures at the unit and at distant duct registersif significantly different, duct leaks are present.X X Low refrigerant charge Check superheat and subcooling per chart.X X Restricted metering device Check superheat and subcooling per chart. Replace.X Defective reversing valve Perform RV touch test.X X Thermostat improperly located Check location and for air drafts behind stat.X X Unit undersized Recheck loads & sizing. Check sensible clg. load and heat pump capacity.X X Scaling in water heat exchanger Perform scaling check and clean if necessary.X X Inlet water too hot or too cold Check load, loop sizing, loop backfill, ground moisture.High Head PressureX Reduced or no air flow in heatingCheck for dirty air filter and clean or replace.Check fan motor operation and air flow restrictions.Too high of external static. Check static vs. blower table.X Reduced or no water flow in cooling Check pump operation or valve operation/setting.Check water flow. Adjust to proper flow rate.X Inlet water too hot Check load, loop sizing, loop backfill, ground moisture.X Air temperature out of range in heating Bring return air temperature within design parameters.X Scaling in water heat exchanger Perform scaling check and clean if necessary.X X Unit overcharged Check superheat and subcooling. Re-weigh in charge.X X Non-condensables in system Vacuum system and re-weigh in charge.X X Restricted metering device. Check superheat and subcooling per chart. Replace.Low Suction PressureX Reduced water flow in heating.Check pump operation or water valve operation/setting.Plugged strainer or filter. Clean or replace.Check water flow. Adjust to proper flow rate.X Water temperature out of range. Bring water temperature within design parameters.X Reduced air flow in cooling.Check for dirty air filter and clean or replace.Check fan motor operation and air flow restrictions.Too high of external static. Check static vs. blower table.X Air temperature out of range Too much cold vent air? Bring entering air temperature within design parameters.X X Insufficient charge Check for refrigerant leaks.Low Discharge Air Temperaturein HeatingX Too high of air flow Check fan motor speed selection and air flow chart.X Poor performance See ‘Insufficient Capacity’High humidity X Too high of air flow Check fan motor speed selection and airflow chart.X Unit oversized Recheck loads & sizing. Check sensible clg load and heat pump capacity.Performance TroubleshootingOnly Compressor RunsX X Thermostat wiring Check G wiring at heat pump. Jumper G and R for fan operationX X Fan motor relay Jumper G and R for fan operation. Check for voltage at blower relay.X X Check fan power enable relay operation (if present).X X Fan motor Check for line voltage at motor. Check capacitor.X X Thermostat wiring Check thermostat wiring at heat pump. Jumper Y1 and R for compressoroperation in test modeUnit Doesn’t Operatein CoolingX Reversing valveSet for cooling demand and check 24VAC on RV coil and at DXM2 board.If RV is stuck, run high pressure up by reducing water flow and while operatingengage and disengage RV coil voltage to push valve.X Thermostat setup Check for ‘O’ RV setup not ‘B’.X Thermostat wiring Check O wiring at heat pump. Jumper O and R for RV coil ‘click’ whencompressor starts.X Thermostat wiringPut thermostat in cooling mode. Check 24 VAC on O (check between C andO); check for 24 VAC on W (check between W and C). There should be voltageon O, but not on W. If voltage is present on W, thermostat may be bad or wiredincorrectly.