Transformer wiring

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Kevin.hndz

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Location
New york
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Electrician
I was told by another electrician to wire up transformer as follows H1 brown H2 Orange H3 yellow X1 black X2 red X3 blue and XO neutral and to install a quad lug for grounds to the transformer case and that all grounds go to quad lug I'm almost 100 certain I have to have a jumper to XO from ground as well right ? First time wiring a transformer please help
 

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Screenshot_20251120-122655.jpgThere should be a bar connected to the enclosure for the connection of the SBJ, EGC, and SSBJ. Looks like it's only a two barrel lug. I would run the EGC to that along with the SBJ from the neutral and everything else GEC, SSBJ, Neutral to the X0.
 
infinity said:
View attachment 2580686There should be a bar connected to the enclosure for the connection of the SBJ, EGC, and SSBJ. Looks like it's only a two barrel lug. I would run the EGC to that along with the SBJ from the neutral and everything else GEC, SSBJ, Neutral to the X0.
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Brown is covering it it's a 4 lug my terminology isn't that great but let's see if I'm correct from the conduit feeding the transformer I have a ground with a migb that goes directly to xo a building steel ground that also goes to xo a jumper from xo to the quad lug secondary conduit that is gonna feed a panel to quad lug .... Did I miss anything ?
 
Kevin.hndz said:
Brown is covering it it's a 4 lug my terminology isn't that great but let's see if I'm correct from the conduit feeding the transformer I have a ground with a migb that goes directly to xo a building steel ground that also goes to xo a jumper from xo to the quad lug secondary conduit that is gonna feed a panel to quad lug .... Did I miss anything ?
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Let's see if we can get the terminology straight:

1) I have a ground with a migb that goes directly to xo. Is this from the primary supply conductors? If so that's an EGC (equipment grounding conductor)
2) a building steel ground that also goes to xo. Sounds like the GEC (grounding electrode conductor)
3) a jumper from xo to the quad lug. Sounds like the SBJ (system bonding jumper)
4) secondary conduit that is gonna feed a panel to quad lug. This conduit has a green conductor that is a SSBJ (supply side bonding jumper)

Do this make sense?
 
infinity said:
Let's see if we can get the terminology straight:

1) I have a ground with a migb that goes directly to xo. Is this from the primary supply conductors? If so that's an EGC (equipment grounding conductor)
2) a building steel ground that also goes to xo. Sounds like the GEC (grounding electrode conductor)
3) a jumper from xo to the quad lug. Sounds like the SBJ (system bonding jumper)
4) secondary conduit that is gonna feed a panel to quad lug. This conduit has a green conductor that is a SSBJ (supply side bonding jumper)

Do this make sense?
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Makes perfect sense thanks for clearing that up so my current connection right now is I went from the the EGC directly to XO after passing through migb good so far ?
 
Kevin.hndz said:
Makes perfect sense thanks for clearing that up so my current connection right now is I went from the the EGC directly to XO after passing through migb good so far ?
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The primary EGC through the MIGB then to the X0? The EGC typically gets terminated to the transformer case.
 
Kevin.hndz said:
I left enough slack to still change that thanks so after my building steel ground GEC would go to case or XO ?
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The GEC can go to either the X0 or the case when the SBJ is a wire type. Many guys will run the GEC through the lug on the case unbroken then on to the X0. In that scenario the GEC will be both the GEC and the second portion the SBJ.
 
Kevin.hndz said:
I left enough slack to still change that thanks so after my building steel ground GEC would go to case ori
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infinity said:
The GEC can go to either the X0 or the case when the SBJ is a wire type. Many guys will run the GEC through the lug on the case unbroken then on to the X0. In that scenario the GEC will be both the GEC and the second portion the SBJ.
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Hmmm so I don't necessarily have to change it ? I can run a jumper from the quad lug to XO ?
 

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Kevin.hndz said:
This is what I currently have as you can see haven't landed the sbj yet I'm I ok so far ?
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It looks correct so far. What I see is the EGC with the primary conductors landed, the SSBJ with the secondary conductors landed and what appears to be the SBJ landed on one end. While were looking at it what are the conductor sizes that you're using for everything?
 
The picture does bring to question the conductor sizes..... reiterating infinity's question...what size are the conductors particularly the jumpers.
 
infinity said:
It looks correct so far. What I see is the EGC with the primary conductors landed, the SSBJ with the secondary conductors landed and what appears to be the SBJ landed on one end. While were looking at it what are the conductor sizes that you're using for everything?
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Conductors are 250 can't remember the ground size right now
 
If you feeders are 250Cu, your bonding jumpers need to be a #2 (250.102) and from the picture that does not seem to be the caee.
 
augie47 said:
If you feeders are 250Cu, your bonding jumpers need to be a #2 (250.102) and from the picture that does not seem to be the caee.
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Hmmm thanks for that info deff something I'll bring up to the lead guy running the job could you point me in the direction of where I can get more info on wire sizes and their bonding jumper sizes
 
Kevin.hndz said:
Hmmm thanks for that info deff something I'll bring up to the lead guy running the job could you point me in the direction of where I can get more info on wire sizes and their bonding jumper sizes
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EGC -T250.122
SBJ and SSBJ-T250.102(C)(1)
GEC-T250.66
 
Kevin.hndz said:
So the ground from the building steel I would land on XO or go to the case ?
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Try to use the correct terminology as it helps with answering the question. The conductor from the building steel is the GEC. It can land on the X0 or it can land on the terminal connected to the case where the SBJ also terminates.

So on your 4 post terminal bolted to the enclosure shown in the photo you can land:
-The EGC from the primary,
-The GEC from the electrode,
-The SSBJ from the secondary, and
-The SBJ from the X0.

If you can fill in the green conductor sizes for the 4 items on the list we can help to ensure that they're the correct sizes.
 
infinity said:
Try to use the correct terminology as it helps with answering the question. The conductor from the building steel is the GEC. It can land on the X0 or it can land on the terminal connected to the case where the SBJ also terminates.

So on your 4 post terminal bolted to the enclosure shown in the photo you can land:
-The EGC from the primary,
-The GEC from the electrode,
-The SSBJ from the secondary, and
-The SBJ from the X0.

If you can fill in the green conductor sizes for the 4 items on the list we can help to ensure that they're the correct sizes.
Click to expand...
EGC from primary is a 4 everything else is #6 I believe
 
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