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what is standard practice , to bond x0 to ground in the transxfmr or bond neutral to ground in the panel it feeds. i bond at the first means of disconnect.L-1 . my supervisor says in Cali. always bond in the trans..i say that means i gotta get more lugs for x0 and the ground cause the trans seems to be set up for parallel neutral feeders, 1 building steel and 2 bomding bushing grounds.
 

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There is no standard practice, and no one freaks out about it here. It should be up to the installer how they do it. I almost always do it at the secondary panel because it keeps the transformer less cluttered and it's extremely simple to pipe out the top of your panelboard to hit your building steel
 

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I say that, because everybody wants to jump to conclusions that its bonded twice because around here it's typical to see it in the tranny.
 

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Chrisibew440 said:
I say that, because everybody wants to jump to conclusions that its bonded twice because around here it's typical to see it in the tranny.
I just assume most people don't understand correct grounding/bonding procedures for separately derived systems.
 

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There is no standard practice, and no one freaks out about it here. It should be up to the installer how they do it. I almost always do it at the secondary panel because it keeps the transformer less cluttered and it's extremely simple to pipe out the top of your panelboard to hit your building steel
....standard practice is to bond at transformer IMO, rarely see it the other way.
 

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360max said:
....standard practice is to bond at transformer IMO, rarely see it the other way.
And for me standard practice is to do it at the panel. I never see it any other way
 

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We just had this discussion at work, huge regional variances.
We have 480V 3ph gear, feeding a xfrmr to feed 208/120 panel. Three electricians and five opinions on the bonding. It actually got heated at one point, all I could do is laugh!
 

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And for me standard practice is to do it at the panel. I never see it any other way
...I work industrial and I have yet to see a 3ph 480v transformer that feeds a 208v panel, bonded at the panel. BTW, the job I'm currently on probable has 500 transformers at a minimum , all 480v primaries, all bonded at TF.
 

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360max said:
...I work industrial and I have yet to see a 3ph 480v transformer that feeds a 208v panel, bonded at the panel. BTW, the job I'm currently on probable has 500 transformers at a minimum , all 480v primaries, all bonded at TF.
You know I'm in industrial as well and transformer installations are kind of my bread and butter. I do about one a week if not more. I simply found a method that works for me and I'll continue to do so. The NEC gives us the option so it's ignorant to say one method is more correct than the other.

I did do 8 square d I-pacs this month where the bonding was done in the transformer section and I slept fine
 

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Has anyone seen a grounded secondary conductor run continuous thru XO lug and then looped around and bonded to XFMR grounding lug unbroken? I had some old schoolers show me that a few times. When I've done it recently my freshly turned out foreman always has me change it. I have not seen it done in awhile. Is this an outdated wiring style or just plain wrong? Of course building steel and pri and sec GEC were installed as well. Please talk amongst yourselves.
 

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Phatstax said:
Has anyone seen a grounded secondary conductor run continuous thru XO lug and then looped around and bonded to XFMR grounding lug unbroken? I had some old schoolers show me that a few times. When I've done it recently my freshly turned out foreman always has me change it. I have not seen it done in awhile. Is this an outdated wiring style or just plain wrong? Of course building steel and pri and sec GEC were installed as well. Please talk amongst yourselves.
I'm struggling trying to envision this to be honest.
 

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I'm struggling trying to envision this to be honest.
Perhaps because you are used to dealing with much larger wire or parallel feeds on a lot of your projects. I'm talking about feeding 200-400 amp panels in commercial and light industrial. Much smaller wire than you might normally deal with. Or, maybe I didn't describe it well.
 
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