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Discussion Starter · #1 ·
I am an industrial maintenance student and had a question on a test that asked what the NEC states maximum motor starter coil voltage is. The correct answer was 120 vac but I looked it up in the NEC and couldn't find it. I asked the instructor and he also said he hasn't seen it published either. The test was written by the former instructor. Has anyone else heard or seen this?
 

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Bilge Rat
motors and controls.........
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That's the dumbest question I've ever seen!!

If the answer is indeed true, then I've violated it about a hundred zillion times.......

I've installed plenty of starters with 480 coils, and I'd bet that the Canadian guys have done tons of 600 volt ones.

A lot of larger starters come from the factory with 480 coils and an interposing relay with a 120 coil.
 

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Discussion Starter · #3 ·
Well I've researched everywhere I know to look and haven't seen anything that remotely comes close to even referring to that. Beats the hell outa me where he come up with that, lol.
 

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Aaaaahhhhh. The days of 480 volt control and no neutral for troubleshooting. I watched my boss get hit with a 480 control circuit. One of the sharpest control guys I'd ever seen too. He didn't wanna talk about.
 

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Never !! Just kidding , well not really I have saw a lot of 600 control circ, but not more than once per job. I change the control to 120 as repairs are needed .
I have a old fertilizer plant I do maintenance at and everything is 600v /347.
Thankfully it's a fertilizer plant not much lasts very long in that environment.
Makes it easy to find a reason to change elect equipment when most things look 50 yrs old,when it's really 5.
 

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Aaaaahhhhh. The days of 480 volt control and no neutral for troubleshooting. I watched my boss get hit with a 480 control circuit. One of the sharpest control guys I'd ever seen too. He didn't wanna talk about.
It's great to meter 277 on each side of a switch to ground and "assume" it's closed.. But when you come back to it later, because nothing else seems wrong and measure 480....:whistling2:
 

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That's the dumbest question I've ever seen...!
Every time I read these test questions I get chest pains.

OP, there is an NFPA 79 control panel standard that says controls shall not exceed 120V to ground, but that is specific to industrial machinery and is not an NEC rule.
 
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