Compressor Running Gear Replacement

PUMP END MAIN BEARING — This bearing is a ma- chined part of the new aluminum oil pump and bearing head casting. Disassemble bearing head. If bearing is scored or worn, replace complete bearing head.

CRANKCASE AND MOTOR END MAIN BEAR- INGS — These bearings are not field replaceable. If bearings are worn or damaged, replace compressor.

CRANKSHAFT — Install crankshaft through pump end, carefully guiding it through main bearings. Replace rotor. Attach equalizer tube assembly to motor end of shaft.

Eccentric shafts must be installed after piston assemblies. Place motor end counterweight on shaft before inserting shaft into compressor. See Piston Assembly Replacement.

PISTON ASSEMBLY — Attach connecting rods or eccentric straps to pistons with piston pins and lock in place with piston pin lock rings. Place lock rings with gap on the side. They should be tight enough so they cannot be rotated by finger pressure.

RINGS

1.Check ring gap by inserting each ring separately in cylinder, approximately 3/8 in. from top. Ring gap should be between .013 and .005 inch.

2.Install compression rings in top piston grooves with side marked “Top” toward piston head. Install oil ring below compression ring with notched end on bottom. Stagger ring gaps around piston.

3.Measure side clearance between ring and piston (Table 6). Check for free action.

PISTON ASSEMBLY REPLACEMENT

Compressors Using Crankshafts — Install connecting rod and piston assemblies into cylinders. Place chamfered sides of connecting rods against radius of crankpins. Install connecting rod caps to matching connecting rods through bottom of crank- case. Be sure chamfered sides of caps are against radius of crankpins. Caps are locked in place with cap screws. Use 8 to 10 lb-ft to tighten cap screws.

Compressors Using Eccentric Shafts — Install eccentric strap and piston assemblies into cylinders. Install eccentric shaft through pump end, carefully guiding it through eccentric straps and main bearings. Install pump end counter- weight to eccentric shaft and replace eccentric strap side shields.

Turn crankshaft or eccentric shaft to be sure there is no binding between bearing surfaces and journals. Replace oil screen, bottom cover plate, valve plates and cylinder heads.

COMPRESSOR MOTOR BURNOUT

Do not attempt start-up with terminal cover removed. Bodily injury or death may result from explosion and/or fire if power is supplied to compressor with the terminal cover removed or unsecured. See warning label on termi- nal cover.

Clean-Up Procedure — If a hermetic motor burns out, the stator winding decomposes, forming carbon, water and acid which contaminate refrigerant systems. Remove these contam- inants from system to prevent repeat motor failures.

1.Close compressor suction and discharge service valves, and bleed refrigerant from compressor. Save remaining refrigerant in system.

2.Check control box for welded contactor contacts, welded overload contacts or burned out heater elements. Check terminal plate for burned or damaged terminals, insula- tion, and shorted or grounded terminals. Repair or replace where necessary.

3.Remove suction and discharge shutoff valve bolts and all other connections to damaged compressor. Remove damaged compressor and replace with new compressor. Replace liquid line filter drier with a drier of one size larger.

4.Purge new compressor. Triple-evacuate, using the follow- ing procedure:

a.Evacuate to 5000 microns.

b.Break vacuum with system refrigerant. Pressurize to 15 psig. Wait 20 minutes to remove moisture.

c.Re-evacuate to 5000 microns.

d.Repeat Step b.

e.Evacuate to 1000 microns or below if possible.

5.Place compressor in operation. After 2 to 4 hours of operation, check compressor oil for signs of discoloration and/or acidity. If oil shows signs of contamination, replace oil charge, filter driers, and clean suction strainer with solvent. Repeat this procedure until oil stays clean and acid free for 48 hours of operation.