Atlas Copco Stationary Air Compressors User Manual

Page of 70
Instruction book 
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10 
 
1.4 Regulating system on SF Skid - Tank-mounted - Twin 
 
The air net pressure is kept within limits by a pressure switch mounted in the cabinet below the control 
panel (Fig. 1.10).  The switch is connected to the air outlet and electrically connected in the circuit of 
the drive motor. The switch opens and closes its contacts at pre-set pressures. 
 
 
 
1 Pressure 
gauge 
2 On/off 
switch 
3 Hourmeter 
Air pressure switch/circuit breaker 
 
Fig. 1.10 Control panel SF Skid - Tank-mounted - Twin 
 
 
When the contacts are closed, the circuit to the drive motor is made: the compressor is operating.  The 
air output is maximum. 
 
When the pressure reaches the pre-set maximum, the circuit to the drive motor is broken, causing the 
compressor to stop.  The air output is stopped. 
 
Protecting the compressor 
The compressor will be shut down in case temperature switch (TSHH11-Fig. 2.7) trips.  
 
Warning 
Before carrying out any inspection or repair, stop the compressor, switch off the voltage, open the 
isolating switch and depressurize the compressor.