Atlas Copco Stationary Air Compressors User Manual

Page of 70
Instruction book 
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34 
 
6 PROBLEM SOLVING 
 
Before carrying out any maintenance or repair: 
1. 
Stop the compressor, switch off the voltage and open the isolating switch. 
2. 
Close the air outlet valve (2-Figs. 1.2/1.4 or 3-Figs. 1.5/1.6) and open the manual drain valve: valve 
(1-Fig. 1.9) on Multi or the valve underneath the air receiver, if provided.   
 
Compressor does not start 
a Loose 
connection 
Have electrical connections checked 
Receiver pressure too high 
Compressor will start when the net pressure drops to the minimum pressure 
 
 
Safety valve blows 
Safety valve opens too soon 
Replace valve  
 
 
Compressor capacity or pressure below normal 
Air consumption exceeds capacity of compressor 
Check equipment connected 
Choked air filter 
Remove and check filter.  Replace if necessary 
Safety valve leaking 
c Replace 
valve 
Drive belt(s) slipping 
Check condition of belt(s).  Correct or replace as required 
 
 
Compressor module overheating / compressor shut down by its air temperature switch 
a Insufficient 
compressor 
cooling 
Improve ventilation of compressor room.   
Cooling fan out of order 
b Check 
and 
correct 
 
 
 
On SF Full-Feature also: 
 
 
Pressure dewpoint too high 
Shortage of refrigerant 
Have circuit repaired or recharged 
Refrigerant compressor does not run 
b See 
Condenser pressure is too high 
c See 
 
 
Condenser pressure too high or too low 
Fan control switch out of order 
Have switch replaced 
Condenser fan motor  out of order 
Have fan motor inspected 
Ambient temperature too high 
Improve ventilation.  If necessary, draw the cooling air from a cooler room 
Condenser externally clogged 
d Clean 
condenser 
 
 
Motor of refrigerant compressor stops or does not start 
Thermal protection of the motor has tripped 
a Compressor 
will 
restart when the motor windings have cooled down