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Inactive, Master Electrician
Category: Electrical
Satisfied Customers: 4772
Experience:  Electrical Contractor
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how to wire 480/240, volt transformer to gt 120 volt wit n

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how to wire 480/240, volt transformer to gt 120 volt wit neutral
Is this a single phase or three phase transformer? Tell me what connections you have on both the primary and secondary terminals.
Customer: replied 7 years ago.
single phase
What about the terminal connections on both the primary and secondary sides. What are they?
Customer: replied 7 years ago.

h1,h2,h3,h4 primary

x1,x2,x3,x4 secondary

is this a small control transformer? What is the units rating? Does it have jumper clips for the terminals?
Customer: replied 7 years ago.
no controll, service transformer 480/240,240/120, nojumper clips hard wired
Does your transformer have a diagram stamped on the side of it?
Customer: replied 7 years ago.
no it has been removed
Do you have a manufacturers number on this or any kind of reference numbers?
Customer: replied 7 years ago.
the only thing i know on this is that it is squqre d single phase
this is how I would hook this up. Run your 480v feeders to H1 and H4. Then run a jumper wire between H2 and H3. Next in order to get 120v, you would jump x1 and x2 - then jump x3 to x4. Dont hook anything up to the secondary. Just power the unit up and check your voltages on the secondary to be sure your getting 120.
Customer: replied 7 years ago.

is x1x2 neutrl,or x3x4

Are you only wanting 120v out of the secondary or 120/220v?
Customer: replied 7 years ago.
120 volt for recepticles
In that case you would take a voltage reading from each terminal to ground to see which one does not register voltage.

Now I must caution you here, my answers to you on this post are based on the fact that most transformers like yours would be wired this way. Without having the manufacturers numbers on the unit, or the units diagram I cannot answer you with 100% certainty. I say this just so you are aware that just because I say it, does not mean it will be true in your case. That is why you must always take voltage readings before hooking any kind of a load up to this.
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