37.5 kva Square D transformer for a rookie

[rojay]

Is it permissible to use the factory jumpers that were landed on the primary side of my single phase transformer? It seems to be set up from the factory in the exact configuration that is needed. Primary side is 240/480 volt- there is a factory jumper from H2 to H3 and the taps are from H1 to #2 and H4 to #7. Looks like the 480 volt primary that I need. On the secondary side X2 and X3 have a bonding strap between them - does it need to be removed and replaced with a wire? I need a 120/240 volt secondary, so I was going to leave the bond in place and add a lug for my neutral there. I find residential doorbell transformers a little easier to figure out

 

[templdl]

Is it permissible to use the factory jumpers that were landed on the primary side of my single phase transformer? It seems to be set up from the factory in the exact configuration that is needed. Primary side is 240/480 volt- there is a factory jumper from H2 to H3 and the taps are from H1 to #2 and H4 to #7. Looks like the 480 volt primary that I need. On the secondary side X2 and X3 have a bonding strap between them - does it need to be removed and replaced with a wire? I need a 120/240 volt secondary, so I was going to leave the bond in place and add a lug for my neutral there. I find residential doorbell transformers a little easier to figure out

I reread you post and you have neglected to advise what the actual primary voltage is. If you measure the voltage and it is actually a real
480v then you are correct. If not then we have to revisits just how to configure the primary taps to assure that the secondary voltage will be close to 120/240v.

 

[rojay]

Primary voltage is 480v. Looked like the two H coils were factory wired in series with the H2- H-3 jumper already in place. Wasn't sure if this was a common practice or if the xfmr may have been used before and sent back.

 

[augie47]

The factory jumpers are normal and do not need to be replaced. Wait until someone more familiar with transformers replies but IMO the taps should be set on the same corresponding numbers as needed.

 

[Canton]

Is it permissible to use the factory jumpers that were landed on the primary side of my single phase transformer? It seems to be set up from the factory in the exact configuration that is needed. Primary side is 240/480 volt- there is a factory jumper from H2 to H3 and the taps are from H1 to #2 and H4 to #7. Looks like the 480 volt primary that I need. On the secondary side X2 and X3 have a bonding strap between them - does it need to be removed and replaced with a wire? I need a 120/240 volt secondary, so I was going to leave the bond in place and add a lug for my neutral there. I find residential doorbell transformers a little easier to figure out

Sounds correct. Your X1 and X4 would be your ungrounded secondary connections. The factory bond/jumper would be on X2 and X3, your neutral and GEC would be bonded here. This would be a typical connection set up for 120/240 single phase.