Carrier PERFORMANCE 50VT-A Installation Instructions Manual

Also see for COMFORT 50VT-A: Owner's information manual Owner's information manual Installation instructions

Contents

Carrier PERFORMANCE 50VT-A Installation Instructions Manual Manual pdf 28 page image

28Puron (R--410A) Refrigerant ChargingRefer to unit information plate and charging chart. Some R--410Arefrigerant cylinders contain a dip tube to allow liquid refrigerant toflow from cylinder in upright position. For cylinders equippedwith a dip tube, charge Puron units with cylinder in uprightposition and a commercial metering device in manifold hose.Charge refrigerant into suction--line.Step 13 — System InformationLoss of Charge SwitchThe loss of charge switch is a protective device wired into controlcircuit (low voltage). It shuts off the compressor if abnormally lowpressures are present in the refrigeration circuit.NOTE: Because these switches are attached to refrigerationsystem under pressure, it is not advisable to remove this device fortroubleshooting unless you are reasonably certain that a problemexists. If switch must be removed, remove and recover all systemcharge so that pressure gauges read 0 psig. Never open systemwithout breaking vacuum with dry nitrogen.Check Defrost ThermostatThe defrost thermostat is usually located on the lowest liquidleaving circuit of the left condenser coil (see Fig. 22). Thethermostat closes at 32_F (0_C) and opens at 65_F (18_C).The defrost thermostat signals heat pump that conditions are rightfor defrost or that conditions have changed to terminate defrost. Itis a thermally actuated switch clamped to outdoor coil to sense itstemperature. Normal temperature range is closed at 32_  3_F (0 1.7_C) and open at 65_  5_F (18  2.8_C).NOTE: The defrost thermostat must be located on the liquid sideof the outdoor coil on the bottom circuit and as close to the coil aspossible.FEEDER TUBESTUB TUBEDEFROSTTHERMOSTATC99029Fig. 22 -- Defrost ThermostatTROUBLESHOOTINGRefer to the Cooling and Heating Troubleshooting Chart (Table10) for troubleshooting information.START--UP CHECKLISTUse the Start--Up Checklist.50VT-- A