220v to 110v single phase 100va transformer inside of a control cabinet?

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BalencedLoad

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San Jose CA
The feed to the control Cabinet is 3 Phase 208v with a ground. There is a 220v to 110v single phase 100va transformer inside that feds two 110v 32watt flourescent ballast. Do i have to bond the grounded conductor (X0) to the grounded system? If so is the equiptment ground sufficiant? or do i have to treat it like a dry type distrabution transformer?:?
 
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BalencedLoad

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Location
San Jose CA
220v to 120v Single Phase transformer inside of a control panel feeding 120v lighting

220v to 120v Single Phase transformer inside of a control panel feeding 120v lighting

I have a tool that came in from china, and had 2 220v flourescent ballast in it. The third party inspector pointed out that the ballast are not listed, come to find out there is not a 220v flourescent listed ballast. I have three phase and a ground feeding the tool, my question is if i install a 100va 220v to 110v transformer what are the grounding and bonding requirements. Do I have to bond X0 to the electrode system, or is there some kind of exception because it is inside of a controll cabinet.
 
augie47

augie47

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Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Since you brought up listing, keep in mind, if you alter the cabinet in any way you have voided it's listing.
That said, there is an exception to 250.30 that allows you to use the grounded cabinet as the electrode for transformers 1000VA or less. Check that section to assure you meet the requirements.
 
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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
BalencedLoad said:
I have a tool that came in from china, and had 2 220v flourescent ballast in it. The third party inspector pointed out that the ballast are not listed, come to find out there is not a 220v flourescent listed ballast. I have three phase and a ground feeding the tool, my question is if i install a 100va 220v to 110v transformer what are the grounding and bonding requirements. Do I have to bond X0 to the electrode system, or is there some kind of exception because it is inside of a controll cabinet.
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The 3rd party inspector should be pointed toward 90.7 if it is a listed item.

But, does a tool have to be listed in your jurisdiction? That would seem to be more important than the ballast issue which is either a non issue due to being part of a listed assembly or a non-issue due to being part of an assembly that is not required to be listed at all, or the non-listed tool can't be used at all due to lack of listing.
 
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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
augie47 said:
Since you brought up listing, keep in mind, if you alter the cabinet in any way you have voided it's listing.
That said, there is an exception to 250.30 that allows you to use the grounded cabinet as the electrode for transformers 1000VA or less. Check that section to assure you meet the requirements.
Click to expand...

you have voided nothing. that is a total myth.

what you have done is altered a listed item, if it was listed in the first place, which is doubtful.

the listing applies as it left the factory. whatever happens to it down the road can't change that.
 
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