Carrier 30GTN Service And Troubleshooting Manual

Also see for 30GTN: Product data Installation instructions Installation instructions

Carrier 30GTN Service And Troubleshooting Manual Manual pdf 52 page image

SERVICEELECTRIC SHOCK HAZARD.Turn off all power to unit before servicing.The ENABLE/OFF/REMOTE CONTACTswitch on control panel does not shut off con-trol power; use field disconnect.Electronic ComponentsCONTROL COMPONENTS — Unit uses an advanced elec-tronic control system that normally does not require service.For details on controls refer to Operating Data section.30GTN,R040-110, AND 230B-315B UNIT CONTROL BOX— When facing compressors, main control box is at left endof unit. All incoming power enters through main box. Con-trol box contains power components and electronic controls.Outer panels are hinged and latched for easy opening. Re-move screws to remove inner panels. Outer panels canbe held open for service and inspection by using door re-tainer on each panel. To use door retainers: remove bottompin from door retainer assembly, swing retainer out horizon-tally, and engage pin in one of the retainer ears and the hingeassembly.30GTN,R130-210, 230A-315A, AND 330A/B-420A/B UNITCONTROLAND MAIN POWER BOXES — The main powerbox is on the cooler side of the unit, and the control box ison the compressor side. Outer panels are hinged and latchedfor easy opening. Remove screws to remove inner panels.Compressors — If lead compressor on either refriger-ant circuit becomes inoperative for any reason, circuit is lockedoff and cannot be operated due to features built into the elec-tronic control system. Do not attempt to bypass controls toforce compressors to run.COMPRESSOR REMOVAL — Access to the pump endof the compressor is from the compressor side of the unit.Access to the motor end of the compressor is from the insideof the unit. All compressors can be removed from the com-pressor side of the unit.IMPORTANT: All compressor mounting hardware andsupport brackets removed during servicing must be re-installed prior to start-up.Following the installation of the new compressor:Tighten discharge valves to —Compressor(s)20 to 25 ft-lb (27 to 34 N-m) 06E25080 to 90 ft-lb (109 to 122 N-m) 06E265,275,299Tighten suction valves to —80 to 90 ft-lb (109 to 122 N-m) 06E25090 to 120 ft-lb (122 to 163 N-m) 06E265,275,299Tighten the following fittings to —120 in.-lb (13.5 N-m) High-Pressure SwitchOIL CHARGE (Refer to Table 28) — All units are factorycharged with oil. Acceptable oil level for each compressor isfrom 1 ⁄8 to 3 ⁄8 of sight glass.When additional oil or a complete charge is required, useonly Carrier-approved compressor oil.Approved oils are as follows:Petroleum Specialties, Inc. — Cryol 150 (factory oil charge)Texaco, Inc. — Capella WF-32Witco Chemical Co. — Suniso 3GSTable 28 — Oil ChargeCOMPRESSOR OIL REQUIREDPts L06E250 14 6.606E265 19 9.006E275 19 9.006E299 19 9.0Do not reuse drained oil or any oil that has been exposedto atmosphere.Cooler — The cooler is easily accessible from the coolerside of the unit. The refrigerant feed components are acces-sible from the control box end of the unit.COOLER REMOVAL — Cooler can be removed from thecooler side of the unit as follows:Open and tag all electrical disconnects before any workbegins. Note that cooler is heavy and both fluid-side andrefrigerant-side may be under pressure.1. To ensure the refrigerant is in the condenser, follow thisprocedure:a. Open the circuit breakers and close the discharge valvesfor the lag compressors in both circuits.Do not close the discharge valve of an operating com-pressor. Severe damage to the compressor canresult.b. After the lag compressor discharge service valves havebeen closed, close the liquid line service valve for onecircuit. Allow the lead compressor to pump down thatcircuit until it reaches approximately 10 to 15 psig(68.8 to 103.2 kPa).c. As soon as the system reaches that pressure, shut downthe lead compressor by opening the compressor cir-cuit breaker, then quickly close the discharge servicevalve for that compressor.d. Repeat the procedure for the other circuit.2. Close the shutoff valves, if installed, in the cooler fluidlines. Remove the cooler fluid piping.3. Cooler may be under pressure. Open the air vent at thetop of the cooler, and open the drain on the bottom of thecooler (near the leaving fluid outlet) to drain the cooler.Both the drain and the air vent are located on the leavingfluid end of cooler. See Fig. 22. Remove the coolerwaterside strainer.4. Disconnect the conduit and cooler heater wires, if equipped.Remove all thermistors from the cooler, being sure to la-bel all thermistors as they are removed. Thermistor T1 isa well-type thermistor, and thermistor T2 is immerseddirectly in the fluid. See Fig. 22.5. Remove the insulation on the refrigerant connection endof the cooler.6. Unbolt the suction flanges from the cooler head. Save thebolts.7. Remove the liquid lines by breaking the silver-solderedjoints at the cooler liquid line nozzles.8. On 30GTN,GTR080-110 and 230B-315B units, removethe vertical support(s) under the condenser coil in frontof the cooler. Provide temporary support as needed. Saveall screws for reinstallation later.9. Remove the screws in the cooler feet. Slide the coolerslightly to the left to clear the refrigerant tubing. Save allscrews.52