GEA Grasso 5 Installation And Maintenance Instructions Manual page 40

INSPECTION AND TROUBLE SHOOTING
TROUBLESHOOTING TABLE GRASSO RECIPROCATING COMPRESSORS
Troubleshooting
FAULT
A
Discharge pressure too high
B
Discharge temperature too high
C
Suction pressure too high
D
Suction pressure too low
E
6
Crankcase frosted or wet *
F
All cylinders inactive while
compressor is operating
G
Too high oil consumption
6
7
40
CAUSE
1. Discharge stop valve not fully open
2. Discharge pressure gauge defective
3. Non-condensables in the system
1. Discharge pressure too high
2. Too many cylinders cut out
3. Suction pressure too low
4. Excessive superheat of suction gas
5. For two-stage compressors: interstage
cooling does not operate properly
6. Room temperature too high
7. Discharge valve defective
8. Pressure relief valve is leaking
1. Capacity control does not operate
2. Compressor capacity too small
3. Suction pressure gauge defective
4. One or more suction valves defective
5. One or more discharge valves defective
6. Pressure relief valve is leaking
1. Suction stop valve not fully open
2. Suction gas strainer blocked
3. Injection control not adjusted correctly
4. Too little refrigerant in installation
5. Suction pressure gauge defective
Warning!
Stop compressor and contact installation engineer
1. Liquid refrigerant in crankcase due to:
1a. Room temperature too low
1b. Oil return from separator contains liquid
refrigerant
1c. Installation operates too wet
1d. Liquid separator too small
1. Oil pressure for valve lifting mechanism
too low
2. Incorrect wiring of capacity control
1. Type of oil not according to oil lubrication
oil table (too thin oil)
2. Compressor operates unloaded too
frequently
3. No return from oil separator *
In case of R744 applications only, crankcase can be frosted or wet, during normal operating conditions.
During the initial start-up, the oil separator (if present) consumes oil before the first oil will be returned.
REMEDY
Open fully
Repair or replace
Purge with a Automatic Purger
See A
Cut in more cylinders
See D
Eliminate excessive superheat
Repair
Ventilate engine room better
Repair or renew
Repair or renew
Repair
Refer to plant design
Repair or renew
Renew suction valve rings
Repair or renew
Repair or renew
Open fully
Renew
Re-adjust control
Top-up with refrigerant
Renew
Provide for crankcase heating or, if provided, check
it for proper operation
Consult plant manual
Re-adjust installation and provide for superheat
Consult plant manual
See J
Refer to the "Product Information"
Change oil type
Refer to design calculations
7
Check the operation of float valve in oil separator
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07.04.2021