Carrier AQUAZONE 50HQL072-120 Installation, Start-up And Service Instructions Manual

Carrier AQUAZONE 50HQL072-120 Installation, Start-up And Service Instructions Manual Manual pdf 38 page image

38Local water conditions may cause excessive fouling orpitting of tubes. Condenser tubes should therefore be cleaned atleast once a year, or more often if the water is contaminated.Proper water treatment can minimize tube fouling andpitting. If such conditions are anticipated, water treatmentanalysis is recommended. Refer to the Carrier System DesignManual, Part 5, for general water conditioning information.Clean condensers with an inhibited hydrochloric acid solu-tion. The acid can stain hands and clothing, damage concrete,and, without inhibitor, damage steel. Cover surroundings toguard against splashing. Vapors from vent pipe are not harmful,but take care to prevent liquid from being carried over by thegases.Warm solution acts faster, but cold solution is just as effec-tive if applied for a longer period.GRAVITY FLOW METHOD — Do not add solution fasterthan vent can exhaust the generated gases.When condenser is full, allow solution to remain overnight,then drain condenser and flush with clean water. Follow acidmanufacturer’s instructions. See Fig. 16.FORCED CIRCULATION METHOD — Fully open ventpipe when filling condenser. The vent may be closed whencondenser is full and pump is operating. See Fig. 17.Regulate flow to condenser with a supply line valve. Ifpump is a nonoverloading type, the valve may be fully closedwhile pump is running.For average scale deposit, allow solution to remain in con-denser overnight. For heavy scale deposit, allow 24 hours.Drain condenser and flush with clean water. Follow acid manu-facturer’s instructions.Checking 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-22, find equivalent saturated condensingtemperature.5. Read liquid line temperature on thermometer; thensubtract from saturated condensing temperature. The dif-ference equals subcooling temperature.Refrigerant ChargingNOTE: Do not vent or depressurize unit refrigerant to atmo-sphere. Remove and recover refrigerant following acceptedpractices.Air Coil Fan Motor RemovalMotor power wires need to be disconnected from motorterminals before motor 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.4. Slide motor/bracket assembly to extreme right and lift outthrough space between fan scroll and side frame. Restmotor on a high platform such as a step ladder. Do notallow motor to hang by its power wires.Follow all safety codes. Wear safety glasses and rubbergloves when using inhibited hydrochloric acid solution.Observe and follow acid manufacturer’s instructions. Fail-ure to follow these safety precautions could result in per-sonal injury or equipment or property damage.To prevent personal injury, wear safety glasses and gloveswhen handling refrigerant. Do not overcharge system —this can cause compressor flooding.Before attempting to remove fan motors or motor mounts,place a piece of plywood over evaporator coils to preventcoil damage.FILL CONDENSER WITHCLEANING SOLUTION. DONOT ADD SOLUTIONMORE RAPIDLY THANVENT CAN EXHAUSTGASES CAUSED BYCHEMICAL ACTION.PAILFUNNELCONDENSERPAIL3’ TO 4’VENTPIPE 5’ APPROX1”PIPEFig. 16 — Gravity Flow MethodSUCTIONPUMPSUPPORTTANKFINE MESHSCREENRETURNGAS VENTPUMP PRIMINGCONN. GLOBEVALVESSUPPLY1” PIPECONDENSERREMOVE WATERREGULATING VALVEFig. 17 — Forced Circulation Method