Truck/Trailer Refrigeration Unit - Sunbelt Transport Refrigeration

k. Slide compressor enough to clear clutch housing andremove compressor from unit.l. Drain oil from defective compressor before shipping.m. The original unloader valves must be transferred tothe replacement compressor. The plug arrangementremoved from the replacement is installed in the originalcompressor as a seal. If piston is stuck, it may be extractedby threading socket head cap screw into top of piston. Asmall teflon seat ring at bottom of piston must beremoved.NOTESThe service replacement compressor is soldwithout shutoff valves (but with valve pads).Customer should retain the original capacitycontrol valves for use on replacementcompressor. Check oil level in servicereplacement compressor. (Refer to sections 1.3,and 4.13)n. Remove the complete high pressure switch assembly(HP-1) and install on new compressor after checkingswitch settings. Remove compressor dischargetemperature sensor (CDT) and suction pressuretransducer and install on new compressor. Installcompressor frame to new compressor (if removed withdefective compressor).o. Install compressor in unit by reversing steps 4.12.cthrough (n). It is recommended using new locknuts whenreplacing compressor. Torque bolts to a value of 46 ft/lb(6.4 mkg). Install new gaskets on service valves andtighten bolts uniformly.p. Attach two lines (with hand valves near vacuumpump) to the suction and discharge service valves.Dehydrate and evacuate compressor to 500 microns(29.90” Hg vacuum = 75.9 cm Hg vacuum). Turn offvalves on both lines to pump.q. Fully backseat (open) both suction and dischargeservice valves.r. Remove vacuum pump lines and install manifoldgauges.s. Start unit and check for noncondensibles.t. Check refrigerant level. (Refer to Section 4.10.1.)u. Check compressor oil level. (Refer to Section 4.13)Add oil if necessary.v. Check compressor unloader operation. (refer toSection 4.14)w. Check refrigerant cycles. (refer to Section 2)4.13 CHECKING COMPRESSOR OIL LEVELa. To Check Oil Level in Compressor:1. Operate the unit in high speed cooling for atleast 20 minutes.2. Check the oil sight glass on the compressor toensure that no foaming of the oil is present after 20minutes of operation. If the oil is foaming excessivelyafter 20 minutes of operation, check the refrigerantsystem for flood-back of liquid refrigerant. Correct thissituation before performing step 3.3. Check the level of the oil in the sight glass withthe compressor operating (See Figure 4-12).05K1/4SightGlass05G--- Maximum--- MinimumFigure 4-12. Oil Level in Sight Glassb. Adding Oil with Compressor in SystemTwo methods for adding oil are the oil pump methodandclosedsystemmethod.1. Oil Pump MethodOne compressor oil pump that may be purchased is aRobinair, part no. 14388. This oil pump adapts to a oneU.S. gallon (3.785 liters) metal refrigeration oilcontainerand pumps 2-1/2 ounces (0.0725 liters) per stroke whenconnected to the suction service valve port. Also there isno need to remove pump from can after each use.When the compressor is in operation, the pump checkvalve prevents the loss of refrigerant, while allowingservicemen to develop sufficient pressure to overcomethe operating suction pressure to add oil as necessary.Backseat suction service valve and connect oilcharging hose to port. Crack the service valve and purgethe oil hose at oil pump. Add oil as necessary.2. Closed System MethodIn an emergency where an oil pump is not available,oil may be drawn into the compressor through the suctionservice valve.CAUTIONExtremecaremustbetakentoensurethemanifold common connection remainsimmersed in oil at all times, otherwise airand moisture will be drawn into thecompressor.Connect the suction connection of the gaugemanifold to the compressor suction service valve port,and immerse the common connection of the gaugemanifold in an open container of refrigeration oil. Crackthe suction service valve and gauge valve to vent a smallamount of refrigerant through the common connectionand the oil to purge the lines of air. Close the gaugemanifold valve.62-028844-14