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#147485 - 10/24/02 10:40 AM Forcing Motor Starter Contactors by Hand?
ROCKPORT Offline
Junior Member

Registered: 10/24/02
Posts: 1
My coworker says it is OK to force a motor starter contactor by hand when troubleshooting or bumping for motor rotation. He says he ohms to ground with Fluke then uses handtool to depress contactor. I say he could loose a hand this way. I would rather troubleshoot the control circuit as to why I can't control remotely. Please let us know your opinions and experiences.

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Arc Flash PPE Clothing, LOTO & Insulated Tools
#147486 - 10/24/02 06:58 PM Re: Forcing Motor Starter Contactors by Hand?
golf junkie Offline
Member

Registered: 04/22/01
Posts: 511
Loc: York, NE
I do it all the time with small motors, less than 20 hp. I can't see a senario where I could potentially "loose a hand".

The biggest danger is to the equipment. If the contactor is not fully closed arcing can quickly damage the starter.

GJ

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#147487 - 10/25/02 08:54 AM Re: Forcing Motor Starter Contactors by Hand?
Redsy Offline
Member

Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
We have entered a new age with regard to electrical safety. Many old practices are no longer considered acceptable. The dangers of arc-flash & blast are coming to the forefront with electrocution.
The practice you describe would not be accepted in a corprate environment where there was a formal electrical safety program.
I imagine the unions would frown upon it as well.

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#147488 - 10/25/02 07:32 PM Re: Forcing Motor Starter Contactors by Hand?
Bjarney Offline
Moderator

Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
Don't forget that plain-vanilla 3-wire control will "latch." If this happens and an upstream disconnet has to be opened, motor regeneration will ususally cause sluggish dropout of contactor.




[This message has been edited by Bjarney (edited 10-26-2002).]

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