Transformer Question

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Ivorytusks

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Louisiana
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Electrical
I recently ran across a 50 kVA transformer rated for single phase 480 on the primary and 240/120 on the secondary
During the service call, i found the primary had a direct short to ground. My question is specific to the connection of the neutral conductor. I found the neutral connected to the primary side the winding and feeding through to the service panel.
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The transformer was wired for single phase 480 votes feeding through H1 and H4. H2 and H3 were jumpered and the Service Neutral was landed there also. Should the service neutral be connected to the primary?
 
Thanks so much
I knew this to be true but began to doubt myself and wondering if perhaps I was misunderstanding my previous training
 
As a follow up question, on the secondary side, X1 and X4 is my 240 V output.
X2 and X3 are jumpered together.

If operational, I would read 240 v between X1 and X4

between X1 & X2, or X3 & X4 I would read 120v. all of that to ask this question;

Shouldn’t my service neutral feeding the panel land on X2 and X3?
 
Ivorytusks said:
As a follow up question, on the secondary side, X1 and X4 is my 240 V output.
X2 and X3 are jumpered together.

If operational, I would read 240 v between X1 and X4

between X1 & X2, or X3 & X4 I would read 120v. all of that to ask this question;

Shouldn’t my service neutral feeding the panel land on X2 and X3?
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Yes if your required secondary output is 120/240 then you would have X1-Ø, X2/X3-N, X4-Ø. You could attach a neutral to the X3 terminal in the photo.

120-240 Transformer.jpg
 
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Welcome to the forum.

Ivorytusks said:
The transformer was wired for single phase 480 votes feeding through H1 and H4. H2 and H3 were jumpered and the Service Neutral was landed there also. Should the service neutral be connected to the primary?
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Definitely not, no way, no how. If anything, that conductor may be able to be re-purposed as a secondary GEC.
 
Ivorytusks said:
Shouldn’t my service neutral feeding the panel land on X2 and X3?
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Technically, no, but again, if suitable (size, color, etc.), you may be able to use it as the GEC by landing it there, and depending on where the other end is terminated.

Now, there should be a new secondary neutral run from the transformer to whatever device it feeds.
 
infinity said:
There is no neutral connection required simply because the primary is dual voltage. It's 2 wires, 1Ø, 480 or 240 so no neutral is needed.
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I know; I was just pointing out that the unit he's using does have H2 and H3 terminals.
 
Thank you so much for all the responses,
I had initially attempted to attach a picture of transformer data plate/wiring diagram but the file was too large
 
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