Carrier 40MFC Service Manual

Also see for 38MFC: Installation instructions Owner's manual

Contents

Carrier 40MFC Service Manual Manual pdf 16 page image

16Outdoor Unit Indoor UnitRefrigerantService ValveLow SideHigh SideABCDA07360Fig. 12 – Service ValveManifold Gage500 micronsLow side valve High side valveCharge hose Charge hoseVacuum pumpLow side valveA07361Fig. 13 – ManifoldDeep Vacuum MethodThe deep vacuum method requires a vacuum pump capable ofpulling a vacuum of 500 microns and a vacuum gage capable ofaccurately measuring this vacuum depth. The deep vacuum methodis the most positive way of assuring a system is free of air andliquid water. (See Fig. 14)500MINUTES0 1 2 3 4 5 6 710001500LEAK INSYSTEMVACUUM TIGHTTOO WETTIGHTDRY SYSTEM2000MICRONS250030003500400045005000A95424Fig. 14 – Deep Vacuum GraphTriple Evacuation MethodThe triple evacuation method should only be used when vacuumpump is only capable of pumping down to 28 in. of mercuryvacuum and system does not contain any liquid water.Refer to Fig. 15 and proceed as follows:1 Pump system down to 28 in. of mercury and allow pump tocontinue operating for an additional 15 minutes.2 Close service valves and shut off vacuum pump.3 Connect a nitrogen cylinder and regulator to system andopen until system pressure is 2 psig.4 Close service valve and allow system to stand for 1 hr. Dur-ing this time, dry nitrogen will be able to diffuse throughoutthe system absorbing moisture.5 Repeat this procedure as indicated in Fig. 15. System willthen be free of any contaminants and water vapor.CHECK FOR TIGHT, DRY SYSTEM(IF IT HOLDS DEEP VACUUM)EVACUATEBREAK VACUUM WITH DRY NITROGENWAITEVACUATERELEASE CHARGE INTO SYSTEMBREAK VACUUM WITH DRY NITROGENEVACUATEWAITA95425Fig. 15 – Triple Evacuation MethodFinal Tubing CheckIMPORTANT: Check to be certain factory tubing on bothindoor and outdoor unit has not shifted during shipment.Ensure tubes are not rubbing against each other or any sheetmetal. Pay close attention to feeder tubes, making sure wire tieson feeder tubes are secure and tight.CONTROL SYSTEMThe 40MFC/MFQ unit is equipped with a microprocessor controlto perform two functions:1 Provide safety for the system2 Control the system and provide optimum levels of comfortand efficiencyThe main microprocessor is located on the control board ofoutdoor unit. Outdoor and indoor units have thermistors used tomonitor the system operation to maintain the unit within acceptableparameters and control the operating mode.