# XFMR Connection



## jar546 (Jun 8, 2011)

How do you connect your transformers?


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## beach (Jun 8, 2011)

In what way are you asking?


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## mark handler (Jun 8, 2011)

http://www.cooperpower.com/library/pdf/r201902.pdf


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## raider1 (Jun 8, 2011)

I don't see a grounding electrode conductor and I am having a hard time seeing the system bonding jumper connection.

Chris


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## jar546 (Jun 8, 2011)

raider1 said:
			
		

> I don't see a grounding electrode conductor and I am having a hard time seeing the system bonding jumper connection.Chris


Yes, me neither


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## raider1 (Jun 8, 2011)

I would also wager that the supply side bonding jumper (formally known as the equipment bonding jumper) is not sized properly. It seems quite small.

Chris


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## chris kennedy (Jun 8, 2011)

raider1 said:
			
		

> I don't see a grounding electrode conductor and I am having a hard time seeing the system bonding jumper connection.Chris





			
				jar546 said:
			
		

> Yes, me neither


Looks like there is an empty lug on X0 right under X2. Maybe the installer isn't finished yet.:lol:


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## jar546 (Jun 9, 2011)

A better pic of the XFMR next to it:


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## beach (Jun 9, 2011)

I didn't know you had a picture attached...... I can't view any of the pics, only the text. Weird....


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## raider1 (Jun 9, 2011)

No, system bonding jumper.

No, grounding electrode conductor

The supply side bonding jumper appears to be too small.

Someone needs a lesson in 250.30. 

Chris


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## jar546 (Jun 9, 2011)

They ran the neutral from XO directly to the neutral bar of the panel/disco and from there ran a GEC.

There is no bonding jumper from XO to the XFMR frame sized IAW 250.66


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## BSSTG (Jun 9, 2011)

That there could smoke the bosses coffee pot. Not a good thing. I did it once!

BS


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## jar546 (Jun 9, 2011)

Let me paint a better picture.

The system bonding jumper IS from the first disconnect as allowed, HOWEVER, it is useless because the GEC is off the frame of the XFMR.

They are going to remove the system bond from the main disconnect and place it from XO to the XFMR frame ground, then move the initial connection point of the GEC from the XFMR frame to XO where there is a lug waiting for it.  Another lug must be added to XO for the system bond jumper.


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## RJJ (Jun 14, 2011)

What are the little smoke marks on the back side of photo #2.


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## jar546 (Jun 16, 2011)

So I have a question.

Do you see more GEC's connected to the XFMR or to the first disco/panel on the secondary side?


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## raider1 (Jun 17, 2011)

jar546 said:
			
		

> So I have a question.Do you see more GEC's connected to the XFMR or to the first disco/panel on the secondary side?


Most of the time in my area the grounding and bonding is done at the transformer and not at the first disconnecting means. That is the way I preferred to do it when I was installing.

Chris


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