Carrier GR-45 Operation And Service

Contents

Carrier GR-45 Operation And Service Manual pdf 44 page image

T-2954-11NOTES1 Service replacement compressors are soldwithout service valves. Valve pads areinstalled in their place. The optionalunloaders are not supplied, as the cylinderheads are shipped with plugs. Customershould retain the original unloader valvesfor use on the replacement compressor.2 The piston plug that is removed from thereplacement compressor head must beinstalled in the failed compressor ifreturning for warranty or core credit.3 Do not interchange allen-head capscrewsthat mount the piston plug and unloader,they are not interchangeable.4 Check oil level in service replacementcompressor. (Refer to paragraphs 1.3 and4.20.3.)f. Remove the three socket head capscrews from thecylinder head(s) that have unloader valves installed.See Figure 4-15. Remove the unloader valve and by-pass piston assembly, keeping the same capscrewswith the assembly. The original unloader valve mustbe transferred to the replacement compressor. Theplug arrangement removed from the replacement isinstalled in the original compressor as a seal. If pistonis stuck, it may be extracted by threading a sockethead capscrew into top of piston. A small Teflon seatring at the bottom of the bypass piston plug must beremoved.GASKETBYPASSPISTONPLUGSPRINGFLANGECOVER(NOT INTERCHANGEABLE WITHCONTROL VALVE SCREWS)COMPRESSORHEADCAPSCREWSFigure 4-15.Removing Bypass Piston Plugg. Remove the pressure switches and install on replace-ment compressor after checking switch operation (re-fer to paragraph 4.10).h. Remove clutch assemble and retain original clutchkey. Install on replacement compressor. Refer toparagraph 4.20.2.i. Install compressor in unit by performing the removalsteps in reverse. It is recommended that new locknutsbe used when replacing compressor. Install new gas-kets on service valves and tighten bolts uniformly.j. Leak check connections and replace filter--drier. Re-fer to paragraph 4.6.k. Using refrigerant hoses designed for vacuum service,connect a vacuum pump (see Figure 4-5) and evacu-ate compressor to 500 microns. Front seat both man-ifold valves to isolate the pump.l. Start unit and check refrigerant level (refer to para-graph 4.8.1).m.Check compressor oil level (refer to paragraph4.20.3). Add or remove oil if necessary.n. Check compressor unloader operation.o. Remove manifold gauge set.4.20.2 Transferring Compressor ClutchTo remove a clutch (see Figure 4-16) from a compressorand install on a replacement compressor, do thefollowing:812346751. Compressor (typical)2. Seal Cover3. Coil4. Rotor5. Rotor Nut6. Armature7 Spacer Nuts8. Snap RingFigure 4-16. Compressor Clutcha. Using a wrench on the armature flats to keep it fromturning, remove the special bolt holding it to theshaft.b. Using special tool (CTD Part Number 07--00242--01), remove the rotor nut and rotor. Retain originalkey.c. Noting the position of the wire, remove the three boltsholding the coil to the compressor.d. Remove every other bolt from the seal cover of thenew compressor in the same manner as the originalcompressor. Mount the coil assembly with the wire inthe same orientation as it was mounted on the originalcompressor. Tighten the mounting bolts to 45 lbs/ft(6.2 mkg).e. Mount rotor on shaft with rotor nut. Be sure pulleyturns freely without binding.f. Install armature on shaft using original key and tight-en mounting bolt to 20 ft/lbs (2.8 mkg).g. Perform a check of the air gap between the inside faceof the armature and the mating face of the rotor. Theair gap should be measured with a minimum of 50psig (3.4 bar) in the crankcase. A preliminary checkmay be performed before the crankcase is pressurizedbut a final check must be performed before the clutchis operated. The gap should be between 0.016 and