Jenny Reciprocating Air Compressors, Operation And Maintenance Manual

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motor. Once the air demand drops the system pressure to a predetermined set point, the pressure
switch activates and closes the switch and subsequently starts the electric motor. Many pressure
switches also contain a special unloading device which relieves the pressure from the compressor
pump when the motor is shut off.
PRESSURE REGULATOR
The pressure regulator is used to maintain a constant outlet pressure. It allows adjustment to
any desired pressure below the maximum outlet pressure of the compressor.
BASE/TANK WELDMENT ASSEMBLY
The base/tank weldment serves two primary functions. First, it gives the air compressor a
rigid structure that was designed specif cally for the operational requirements of the unit. Secondly,
the weldment provides the mounting capability for all of the major components of the compressor
assembly.
MAGNETIC STARTER
A magnetic starter is included on all models 5HP and larger on simplex and all duplex single
phase units and three phase units. The magnetic starter works in conjunction with a pressure switch
to start and stop the electric motor. The magnetic starter is primarily a switch which can take the full
load of starting and stopping an electric motor when other switching devices are incapable of handling
this load. Starters typically are made of two components; the contractor and a heater overload block.
The contractor is a switch designed to engage and disengage all the power to an electric
motor.
The heater overload block is a protective device for the motor. If the motor draws over a preset
number of amps, the overload will disengage the starter and shut the unit down.
CHECK VALVE (Start-Stop Units and All 2-Stage Units)
The check valve functions by allowing air to only move in one direction. This is required and
accomplished when the unit switches into either unload (Constant Run Unit) or stopped (Start-
Stop Unit) mode of operation. In this situation, the air receiver pressure is built up to the maximum
pressure. The pilot valve or pressure switch senses the pressure and at this point either closes the air
intake valves or turns off the motor.
RELIEF VALVE
A pressure relief valve is mounted on the manifold assembly or on the receiver. In the event
that air pressure continues to build when the demand for compressed air has either slowed or ceased
altogether, the relief valve will open at a predetermined set point and allow excess pressure to
discharge into the atmosphere. In most cases, this is an indication that there has been a failure in air
system somewhere and the cause should be investigated immediately.
AIR INTAKE FILTER(S)
Air f lters are designed to remove foreign particles from the air entering the pump. Keeping the f lters
clean and free from obstructions will ensure the pump continually receives a clean air supply.