Transformer

H

hhsting

Senior Member
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Glen bunie, md, us
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Junior plan reviewer
I have the following type of transformer

a528367e3d4dfb4ec0b7d05c0fb93dc9.jpg


My questions are as follows:


1. Would rules of NEC 2017 Article 450.5 apply to this type transformer or not?

2. Would the transformer considered separately derived system or not? Should it have system bonding jumper or not?


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hhsting said:
I have the following type of transformer

a528367e3d4dfb4ec0b7d05c0fb93dc9.jpg


My questions are as follows:


1. Would rules of NEC 2017 Article 450.5 apply to this type transformer or not?

2. Would the transformer considered separately derived system or not? Should it have system bonding jumper or not?


Sent from my iPhone using Tapatalk
Click to expand...

Is anyone familiar with the type of transformer?


Sent from my iPhone using Tapatalk
 
Sounds like a fairly normal low voltage transformer, just with a zig-zag secondary winding rather than a more typical wye secondary.

I see no reason to think that different rules would apply to this transformer.

-Jonathan
 
winnie said:
Sounds like a fairly normal low voltage transformer, just with a zig-zag secondary winding rather than a more typical wye secondary.

I see no reason to think that different rules would apply to this transformer.

-Jonathan
Click to expand...

I dont see secondary zig zag windings to have grounding electrode, grounding electrode conductor and system bonding jumper where is that in NEC 2017?
 
hhsting said:
I dont see secondary zig zag windings to have grounding electrode, grounding electrode conductor and system bonding jumper where is that in NEC 2017?
Click to expand...
You don't see wye or delta in the code either. The zig zag has a center point just like a wye
 
don_resqcapt19 said:
You don't see wye or delta in the code either. The zig zag has a center point just like a wye
Click to expand...
The zig-zag is most typically an autotransformer, with the primary and secondary windings interconnected.
I dont think i have ever seen a zig-zag secondary only.
 
I've seen it both ways.

A zig-zag autotransformer to derive a neutral is one use.

A delta:zig-zag to get different primary: secondary phase shift is another.
 
winnie said:
A delta:zig-zag to get different primary: secondary phase shift is another.
Click to expand...
Can you post a link to a manufacturer's wiring diagram? You would need two sets of secondary windings one configured in a wye and one in a delta.
 
jim dungar said:
The zig-zag is most typically an autotransformer, with the primary and secondary windings interconnected.
I dont think i have ever seen a zig-zag secondary only.
Click to expand...
Thinking back, I believe the only one I ever installed looked the zig-zag in the drawing below.
1771696690324.png
 
jim dungar said:
Can you post a link to a manufacturer's wiring diagram? You would need two sets of secondary windings one configured in a wye and one in a delta.
Click to expand...



1771704160926.png

Hope those help...I only know about them because I've seen them while reading. I've never had occasion to actually use them.
 
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