Carrier 50JZ024 Installation, Start-up And Service Instructions Manual

Also see for 50JZ024: Installation and operating instructions Guide to operating and maintaining Guide to operating and maintaining Product data Product data

Contents

REFRIGERANT CIRCUIT — Inspect all refrigerant tubing con-nections and the unit base for oil accumulation annually. Detectingoil generally indicates a refrigerant leak.If oil is detected or if low performance is suspected, leak-test allrefrigerant tubing using an electronic leak detector, or liquid-soapsolution. If a refrigerant leak is detected, refer to Check forRefrigerant Leaks section.If no refrigerant leaks are found and low performance is suspected,refer to Checking and Adjusting Refrigerant Charge section.INDOOR AIRFLOW — The heating and/or cooling airflow doesnot require checking unless improper performance is suspected. Ifa problem exists, be sure that all supply- and return-air grilles areopen and free from obstructions, and that the air filter is clean.When necessary, refer to Indoor Airflow and Airflow Adjustmentssection to check the system airflow.METERING DEVICES—ACCURATER® PISTON — This me-tering device is a fixed orifice and is contained in the brasshex-body in the liquid line feeding the indoor and outdoor coils.PRESSURE SWITCHES — Pressure switches are protective de-vices wired into control circuit (low voltage). They shut offcompressor if abnormally high or low pressures are present in therefrigeration circuit. These pressure switches are specificallydesigned to operate with Puron (R-410A) systems. R-22 pressureswitches must not be used as replacements for the Puron (R-410A) system.LOSS OF CHARGE/LOW-PRESSURE SWITCH (AIR CONDI-TIONER ONLY) — This switch is located on the liquid line andprotects against low suction pressures caused by such events asloss of charge, low airflow across indoor coil, dirty filters, etc. Itopens on a pressure drop at about 20 psig. If system pressure isabove this, switch should be closed.To check switch:1. Turn off all power to unit.2. Disconnect leads on switch.3. Apply ohmeter leads across switch. You should have conti-nuity on a good switch.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 psi. Never open systemwithout breaking vacuum with dry nitrogen.HIGH-PRESSURE SWITCH — The high-pressure switch is lo-cated in the discharge line and protects against excessive con-denser coil pressure. It opens at 610 psig.High pressure may be caused by a dirty outdoor coil, failed fanmotor, or outdoor air recirculation.To check switch:1. Turn off all power to unit.2. Disconnect leads on switch.3. Apply ohmeter leads across switch. You should have conti-nuity on a good switch.COPELAND SCROLL COMPRESSOR (PURON REFRIGER-ANT) — The compressor used in this product is specificallydesigned to operate with Puron (R-410A) refrigerant andcannot be interchanged.The compressor is an electrical (as well as mechanical) device.Exercise extreme caution when working near compressors. Powershould be shut off, if possible, for most troubleshooting tech-niques. Refrigerants present additional safety hazards.Wear safety glasses and gloves when handling refrigerants.Keep torches and other ignition sources away from refriger-ants and oils. Failure to follow this warning can cause a fire,serious injury, or death.The scroll compressor pumps refrigerant throughout the system bythe interaction of a stationary and an orbiting scroll. The scrollcompressor has no dynamic suction or discharge valves, and it ismore tolerant of stresses caused by debris, liquid slugging, andflooded starts. The compressor is equipped with an anti-rotationaldevice and an internal pressure relief port. The anti-rotationaldevice prevents the scroll from turning backwards and replaces theneed for a cycle protector. The pressure relief port is a safetydevice, designed to protect against extreme high pressure. therelief port has an operating range between 550 and 625 psidifferential pressure.The Copeland scroll compressor uses Mobil 3MA POE oil.This is the only oil allowed for oil recharge.REFRIGERANT SYSTEMREFRIGERANTThis system uses Puron® (R-410A) refrigerant which hashigher operating pressures than R-22 and other refrigerants.No other refrigerant may be used in this system. Gauge set,hoses, and recovery system must be designed to handlePuron. If you are unsure consult the equipment manufacturer.Failure to use Puron compatible servicing equipment orreplacement components may result in property damage orinjury.COMPRESSOR OIL — The compressor in this system uses apolyolester (POE) oil, Mobil 3MA POE. This oil is extremelyhygroscopic, meaning it absorbs water readily. POE oils canabsorb 15 times as much water as other oils designed for HCFCand CFC refrigerants. Take all necessary precautions to avoidexposure of the oil to the atmosphere.SERVICING SYSTEMS ON ROOFS WITH SYNTHETIC MA-TERIALS — POE (polyolester) compressor lubricants are knownto cause long term damage to some synthetic roofing materials.Fig. 30—Refrigerant CircuitC9909721