Switches for Compressor/Pumps in Local Panel/System

in an automated system(controlled by a computer or programmable unit it is necessary to operate the machinery for service and maintenance purposes. in these situations a "Field or manual" switch is needed to bypass the computer program and force a start of individual components such as a fan or pump. waiting for a timed start might take hours. the system needs to have the ability to be over-ridden in the field for testing

In the normal course of events these controls would be mounted on the cubicle door for the starter in question, although it is not unknown to use a local control station next to the equipment itself. Local circumstances will determine the correct approach and those cannot be seen from here.

Such consideration should be left to the process engineer, controls engineer and the maintenance engineer who will together design the system.

Too much detail has not been given here for a competent answer.

This decision shall be taken by process engineers in consultations with operations people. Also during process HAZOP this will be evaluated . There is no standard or guidelines, its more a question of operational philosophy adopted by a company/ operator.