Safety Mechanisms for Electro-Pneumatic Controls

Hazards and Protective Mechanisms

Safe operation of electro-pneumatic controls requires extensive safety mechanisms.



Hazards due to moving Machine and Plant Components

One major cause of danger is posed by moving machine and plant components such as cylinders, grippers, shafts, presses etc. In a pneumatic press, for example, it is necessary to ensure that no part of the operator's body (such as fingers) can become trapped in the machine. The following list summarises the relevant protective measures. hazards-protective-mechanisms.jpg
Protection via encapsulation or protective covering
Protective cage
Protective grilles


Protection via controls and indicators
Warning and indicator lights
Emergency shut-off switch
Two-handed safety controls (requiring the operator to use both hands)


Protection internal to the signal processing procedure
Protection against unauthorised starting
Priming procedure


Hazards due to Electrical Power

An important source of danger is posed by the elect4rical current flowing through components such as power supplies, sensors, directional control valves etc. The respective safety regulations are laid out in specifications for protection of high-voltage equipment (e.g. DIN VDE 0100) or electrical wiring and safety for machines (e.g. DIN/EN 60204). The following list summarises the most important protective measures. hazards-protective-mechanisms1.jpg


Protection  for excess contact voltage
Safety extra-low voltage
Housings or covers
Sufficient safety perimeter


Protection during maintenance and repair work
Main switch (with separate locking mechanism)


Protection of electrical components against environmental influences
Protection against water and damp
Protection against dust and foreign matter

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