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Section 5 • Maintenance/Service
Preventive Maintenance, Checks and
Services
Careful checking of a refrigeration system for leaks and
proper operation of all components upon installation
will start the system on its way to a long life of satisfac-
tory service. To ensure the desired trouble-free opera-
tion, however, a systematic maintenance program is a
prerequisite. The following PMCS is suggested in addi-
tion to the Maintenance/Service Schedule.
After any maintenance work, the workplace should be
cleaned and free from any hazards.
Daily
1.
Check oil levels.
2.
Check all pressure and temperature readings.
3.
Check micronic oil filter inlet and outlet pressures
for excessive pressure drop. Change filter when
pressure drop exceeds 45 psi or every six months,
whichever occurs first. For proper procedure for
changing micronic oil filter and for charging oil into
the system, see Operation Section.
4.
Clean strainers each time filter cartridge if replaced.
5.
Check compressor sound for abnormal noises.
6.
Check shaft seals for excessive oil leakage. A small
amount of oil leakage (approximately 6 to 15 drops
per hour) is normal. This allows lubrication of the
seal faces.
Weekly
(Items 1 thru 6 above plus 7 thru 9)
7.
Check the refrigeration system for leaks with a suit-
able leak detector.
8.
Check oil pressures and review microprocessor log
and log sheets.
9.
Check refrigerant levels in vessels.
Monthly
(Items 1 thru 8 above plus 9 thru 13)
10. Oil all motors and bearings. Follow manufacturer's
instructions on lubrication.
11. Check calibration and operation of all controls, par-
ticularly safety controls.
12. Check oil cooler for any evidence of corrosion, scal-
ing or other fouling.
5 – 4
NOTE
VSS/VSM/VSH/VSSH • Installation, Operation and Maintenance Manual • Emerson • 35391SD
13. Operate compressor capacity and volume ratio
controls through their range both automatically
and manually.
Trimonthly
(Approximately 2000 operating hours)
A. Check movement of compressor rotor at drive cou-
pling end to determine bearing float, see Compressor
Shaft Bearing Float Inspections.
Annually
(Items 1 thru 13 and "A" above plus 14 thru 31)
14. Check entire system thoroughly for leaks.
15. Remove all rust from equipment, clean and paint.
16. Grease valve stems and threads for the valve caps.
17. Flush out sediment, etc. from water circuits.
18. Clean all oil strainers.
19. Clean suction strainer – compressors.
20. Check motors and fans for shaft wear and end play.
21. Check operation and general condition of micro-
processor and other electrical controls.
• Check fuses in the Vission20/20 or PLC panel.
• Check for loose wiring connections in the Vission
20/20 or PLC panel.
• Check relay and contact operation for relays in the
Vission20/20 or PLC panel.
• Verify set points in the Vission20/20 or PLC.
22. Clean all water strainers.
23. Check drains to make sure water will flow away
from equipment.
24. Drain and clean entire oil system at receiver drain.
Recharge with new clean moisture free oil. For
proper procedure for changing micronic oil filter
and charging oil into the system, see Start-Up and
Operation section.
25. Check compressor coupling. For integrity and
alignment.
26. Check oil pump for wear.
27. Check the calibration of the microprocessor pres-
sure transducers and RTD's for accuracy.
28. Check mounting bolts for compressor and motor.
29. Verify the operation of the suction and discharge
check valves.
30. Check setup of soft starts and VFDs.
31. Check oil heater operation.
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Table of Contents
Troubleshooting
