Safety of Reciprocating Compressor

Pay particular attention to the first site below.
Finding Information on the Internet: Table of Contents

1. How It Works: Air Compressor - Popular Mechanics
   Compressors: How They Work

The electrical safety and all safety is integrated into the design of the compressor. DO NOT MESS WITH IT!

How seriously you want to know these fundamental? these are two different specifications which you are asking.

Basic electrical protection is achieved through electrical controles, which save the compressor beyond certain amount of power drawn by compressor. Motor gets trip due to pre set values of current on the relay.

Compressor loading unloading is the feature of the machine and yes this works with help of pressure switch. Variable suction valves are fitted with loader/unloader actuators may be hydraulic/pneumatic or electrical which are interlocked with header pressure switch for automatic control of header pressure and optimum power consumption.

Once it's up to pressure, the switch turns it off. Quite simple, really.

Compressors such as reciprocating units are controlled using two types of controls. The 1st is most common on compressors sold to home owners. They control the unit by shutting down the motor once the pressure setting on the pressure switch has been reached. The other style of unit is used in an industrial setting, where the motor stays energized and the valves are cycled open or closed in the working state. Thus the motor run continuously and air is only compressed when the pressure differential has been reached that has been set up witha pressure regulator system desgined for this operation.

I hope this helps you to understand the different operations.