Single Phase Transformer

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Rush is my band

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Please Help !


I got a 10KVA single phase Transformer h2 h3 wire together h1 & h4 to 480V power now I have this 10 x 50 trailer that has lighting plus and 220 AC unit do I take x1 & x4 to the trailers panel for 240V wire together x2 & x3 and run to the neutral or ground bar at the 240 panel do I need both how do I get a ground and neutral????

Rush
 
generally ground and neutral are derived at the transformer at X0 bonded to ground and case. however, you need to provide more details. what's the ratio, input and output you currently have ?
 
For a typical 240x480-120/240, your wiring is correct.

Your transformer secondary will not have an X0 busing because it is a single phase device.

The X2-X3 connection must be connected to ground regardless if you are using any 120V loads or not, 250.20(D) refers you back to 250.20(B)(1).
 
Rush is my band said:
Please Help !


I got a 10KVA single phase Transformer h2 h3 wire together h1 & h4 to 480V power now I have this 10 x 50 trailer that has lighting plus and 220 AC unit do I take x1 & x4 to the trailers panel for 240V wire together x2 & x3 and run to the neutral or ground bar at the 240 panel do I need both how do I get a ground and neutral????

Rush
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As Jim mentioned, your primary lines if at 480V will be connected to H1 & H4. Terminals H2 & H3 will require a jumper no smaller than the 480V line conductors. A grounding conductor run with the primary line conductors will need to be bonded to the transformer frame/enclosure.

The secondary is wired similar to the primary. Connect your secondary line conductors L1 to X1 and L2 to X4. Terminals X2 & X3 will require a jumper, again no smaller than the secondary line conductors. Your secondary neutral conductor (N) will also be connected to either X2 or X3.

The neutral is required to be a grounded conductor but without more detail on the installation it is difficult to pin down exactly how it should be grounded. Is the "trailer" a manufactured building, or a mobile/manufactured home (and is it intended to be used as a dwelling or not)? Requirements for these differ in how they are to be served.
 
The trailer will be used to hold company records in boxes

I have four wires coming from the trailer L1, L2, Ground , Neutral

L1 to X1 at transformer

L2 to X4 at transformer

Neutral bar to X2 & X3 wired together

Ground bar to transformer case
 
Don't forget, this is a separately derived system. You need to bond your neutral and ground (actually GEC) together either at the transformer or the first disconnect.
 
jim dungar said:
Don't forget, this is a separately derived system. You need to bond your neutral and ground (actually GEC) together either at the transformer or the first disconnect.
Click to expand...
If this "trailer" is a mobile/manufactured home (per mfr label), there needs to be a disconnect within 30', but not on the exterior of the trailer.

If it is a manufactured building, it can be served like any other additional building on premises.
 
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