Carrier GT-PX Split Series Installation, Operation & Maintenance Instructions Manual

R e s i d e n t i a l S p l i t - 6 0 H z R 2 2 & R 4 1 0 AR e v. : 5 J u n e , 2 0 0 818 W a t e r- S o u r c e H e a t i n g a n d C o o l i n g S y s t e m sRefrigeration InstallationFigure 10: Braze InstructionsFully InsulatedSuction LineFully InsulatedLiquid LineNitrogen BrazeService ports forgaugesCCWCCWRev. 05/31/00Replace Caps after adjustingservice valvesBrazeconnectionService ports forattaching refrigerantgaugesReplace capsafter adjustingservice valvesTable 5: Service Valve PositionsFigure 11: Air Coil ConnectionTXV (‘IN’ towardcompressor section)Suction LineLiquid LineBulb(Must beInsulated)EqualizerLineTXV has internalcheck valveInstalling the Indoor Coil and LinesetFigure 11 shows the installation of the lineset and TXV to atypical indoor coil. An indoor coil or air handler (fan coil) with aTXV is required. Coils with cap tubes may not be used. If coilincludes removable fixed orifice, the orifice must be removedand a TXV must be installed as shown in Figure 11. Fastenthe copper line set to the coil. Nitrogen should be circulatedthrough the system at 2-3 psi [13.8-20.7 kPa] to preventoxidation inside the refrigerant tubing. Use a low silver phos-copper braze alloy on all brazed connections.Add-On Heat Pump ApplicationsThe indoor coil should be located in the supply side ofthe furnace to avoid condensation damage to the furnaceheat exchanger for add-on heat pump applications. A hightemperature limit switch should be installed as shown in Figures12b and 13b just upstream of the coil to de-energize thecompressor any time the furnace is energized to avoid blowinghot air directly into the coil, elevating refrigerant pressuresduring operation. The heat pump will trip out on high pressurelockout without some method of disengaging the compressorduring furnace operation. Alternatively, some thermostats with“dual fuel” mode will automatically de-energize the compressorwhen second stage (backup) heat is required.The TXV should be brazed into place as shown in Figure 11,keeping the “IN” side toward the compressor section. TheTXV has an internal check valve and must be installed in theproper direction for operation. Always keep the valve bodycool with a brazing shield and wet rags to prevent damageto the TXV. Attach the bulb to the suction line using thesupplied hose clamp. Be careful not to overtighten the clampand deform the bulb.NOTICE! The air coil should be thoroughly washed with afilming agent, (dishwasher detergent like Cascade) to helpcondensate drainage. Apply a 20 to 1 solution of detergentand water. Spray both sides of coil, repeat and rinsethoroughly with water.Evacuation and Charging the UnitLEAK TESTING - The refrigeration line set must be pressurizedand checked for leaks before evacuating and charging the unit.To pressurize the line set, attach refrigerant gauges to the serviceports and add an inert gas (nitrogen or dry carbon dioxide) untilpressure reaches 60-90 psig [413-620 kPa]. Never use oxygen oracetylene to pressure test. Use a halogen leak tester or a goodquality bubble solution to detect leaks on all connections madein the field. Check the service valve ports and stem for leaks. Ifa leak is found, repair it and repeat the above steps. For safetyreasons do not pressurize system above 150 psig [1034 kPa].System is now ready for evacuation and charging.