Ring circuit and emergency stop buttons on a contactor

[ColJack]

the simple solution to stopping someone messing withthe contacts is to put a padlock on the control panel door, welded on so no screws to remove, the only persons to have a key would be the maintainence staff..

another way would be security tamperproof screws and a seal on the cabinet.

fit with a very loud siren that sounds if the seals are broken and the door opened.. ( battery backed so they can't turn the power off, could double as a siren for power loss by using a phase relay to monitor for all 3 phases in the correct rotation )

 

[JACKC]

vsynth wrote.
How do you stop someone jamming in a contactor or shorting it out with wires?
As Coljack said, all of our panels are only opened by a service key, only maintenance have them. If you have one in your posession at our work and are not maintenance it is goodbye regardless of why you have it. CCTV also helps cut down on the "it just broke" type of breakdowns. A factory full of Portugeuse workers who actually want to work has cut down on a lot of our mystery damage also.