Electrically operated power circuit breakers vs. manual 1

[bdn2004]

We are installing new 480 Volt switchgear. There are large motors and motor control center feeders fed from it. There is a choice between electrically operated and manually operated power circuit breakers. Is there any advantage of getting the manual circuit breakers? The engineering firm is recommending them for the motor control center feeder breakers.

 

[dpc]

Unless you need automatic or remote control of the breakers, manual operator will be much simpler and less expensive. If you are using the breaker as a motor controller, it will need to be electrically operated. But a feeder to an MCC can be manually operated.

 

[oldfieldguy]

One consideration you should address: The manually-operated breakers will require that the operator stand in close proximity to the front of the breaker to operate. Many users are trying to avoid this manner of operation in the interests of safety... the 'arc-flash' thing...

old field guy

 

[dpc]

Yes, oilfieldguy brings up a good point. Electrically operated breaker would allow for remote closing and reduce arc-flash exposure.

 

[ruggedscot]

Speaking from experiance here - You should go for the remote operated breaker for safety's sake - cost isnt really that much more when you consider all the outside factors. We had a situation a few months back where we lost two breakers through a fault - These breakers were on a 415v 3ph circuit and the failure was catastropic to the point that the breakers went bang caught fire and burned down an electrical switchboard. Scary when you are in the immediate aftermath even scarier if you were in the direct vicinity of the breaker.

Only but for the grace of god there wss no one injured or killed. It would have been so easy that day to have lost someone. So as you can imagine Im all for getting out of the way of the switching and having it remotely done.

Remember the fault energy availiable is pretty high right at the transformer incomer.....