Carrier AQUAZONE 50PTH Installation And Service Instructions Manual

45Checking System Charge — Units are shipped withfull operating charge. If recharging is necessary:1. Insert thermometer bulb in insulating rubber sleeve onliquid line near filter drier. Use a digital thermometer forall temperature measurements. DO NOT use a mercuryor dial-type thermometer.2. Connect pressure gage to discharge line near compressor.3. After unit conditions have stabilized, read head pressureon discharge line gage.NOTE: Operate unit a minimum of 15 minutes beforechecking charge.4. From standard field-supplied Pressure-Temperature chartfor R-410A refrigerant, find equivalent saturated con-densing temperature.5. Read liquid line temperature on thermometer; thensubtract from saturated condensing temperature. The dif-ference equals subcooling temperature.6. Compare the subcooling temperature with the normaltemperature listed in Tables 20-23. If the measured liquidline temperature does not agree with the required liquidline temperature, ADD refrigerant to raise the tempera-ture or REMOVE refrigerant (using standard practices) tolower the temperature (allow a tolerance of ± 3° F).Refrigerant ChargingNOTE: Do not vent or depressurize unit refrigerant to atmo-sphere. Remove and recover refrigerant following acceptedpractices.Air Coil Fan Motor RemovalDisconnect motor power wires from motor terminals beforemotor is removed from unit.1. Shut off unit main power supply.2. Loosen bolts on mounting bracket so that fan belt can beremoved.3. Loosen and remove the 2 motor mounting bracket boltson left side of bracket.Slide motor/bracket assembly to extreme right and lift outthrough space between fan scroll and side frame. Rest motor ona high platform such as a step ladder. Do not allow motor tohang by its power wires.Replacing the WSHP Open Controller’s Bat-tery — The WSHP Open controller’s 10-year lithiumCR2032 battery provides a minimum of 10,000 hours of dataretention during power outages.NOTE: Power must be ON to the WSHP Open controllerwhen replacing the battery, or the date, time and trend data willbe lost.1. Remove the battery from the controller, making note ofthe battery's polarity.2. Insert the new battery, matching the battery's polaritywith the polarity indicated on the WSHP Open controller.TROUBLESHOOTINGWhen troubleshooting problems with a WSHP, consider thefollowing:Thermistor — A thermistor may be required for single-phase units where starting the unit is a problem due to lowvoltage. See Fig. 37 for thermistor nominal resistance.Control Sensors — The control system employs 2 nom-inal 10,000 ohm thermistors (FP1 and FP2) that are used forfreeze protection. Be sure FP1 is located in the discharge fluidand FP2 is located in the air discharge. See Fig. 38.Fig. 35 — Gravity Flow MethodFILL CONDENSER WITHCLEANING SOLUTION. DONOT ADD SOLUTIONMORE RAPIDLY THANVENT CAN EXHAUSTGASES CAUSED BYCHEMICAL ACTION.PAILFUNNELCONDENSERPAIL3’ TO 4’VENTPIPE 5’ APPROX1”PIPESUCTIONPUMPSUPPORTTANKFINE MESHSCREENRETURNGAS VENTPUMP PRIMINGCONN. GLOBEVALVESSUPPLY1” PIPECONDENSERREMOVE WATERREGULATING VALVEFig. 36 — Forced Circulation MethodWARNINGTo prevent personal injury, wear safety glasses and gloveswhen handling refrigerant. Do not overcharge system —this can cause compressor flooding.CAUTIONBefore attempting to remove fan motors or motor mounts,place a piece of plywood over evaporator coils to preventcoil damage.