110v transformer to air compressor

Mattydh · Jan 2, 2022

I recently brought a 110v aircompressor but when I brought it I was told I could run it through a transformer box as i work on site which worked fine for a month but now the transformer box keeps tripping and has even blown the fuse in the plug.

Am I right to run it through a transformer box? Is the compressor faulty??

I appreciate any help I can get?

ImpededLoop · Jan 2, 2022

It could be that the power rating of the compressor (in kW or kVA) is too large for the transformer. Could you have a look at the compressor and let us know what the rating is, and the same for the transformer. We'll then be able to help a bit more.

westward10 · Jan 2, 2022

Most "site" transformers will have a rating for example 3kva but this is not necessarily its continuous rating more often it is an intermittent rating. The compressor is likely to run continuous so you may well have exceeded the transformers continuous rating.

Mattydh · Jan 2, 2022

ImpededLoop said:
It could be that the power rating of the compressor (in kW or kVA) is too large for the transformer. Could you have a look at the compressor and let us know what the rating is, and the same for the transformer. We'll then be able to help a bit more.

It says the compressor is 1500kw and the transformer has a 3000va but continues at 1650va if that helps

Mattydh · Jan 2, 2022

westward10 said:
Most "site" transformers will have a rating for example 3kva but this is not necessarily its continuous rating more often it is an intermittent rating. The compressor is likely to run continuous so you may well have exceeded the transformers continuous rating.

Is it possible to buy a transformer with a higher continuous rating as I have to plug it in to standard plug sockets.

westward10 · Jan 2, 2022

I assume you mean 1.5kw or 1500w?

Mattydh · Jan 2, 2022

[ElectriciansForums.net] 110v transformer to air compressor

westward10 · Jan 2, 2022

If your load were purely resistive then that transformer would be fine but it isn't. Using a power factor of .80 your motor is pushing 1900va and without further info I would be looking at a continuous rating of 2500va, minimum.

Mattydh · Jan 2, 2022

westward10 said:
If your load were purely resistive then that transformer would be fine but it isn't. Using a power factor of .80 your motor is pushing 1900va and without further info I would be looking at a continuous rating of 2500va, minimum.

Thanks for your help

So if I brought a transformer with a higher continuous rating as you suggest it could stop it tripping?

ian.settle1 · Jan 2, 2022

If your in the UK instead of messing about with a transformer just change the motor for a 230v motor

westward10 · Jan 2, 2022

Mattydh said:
Thanks for your help
So if I brought a transformer with a higher continuous rating as you suggest it could stop it tripping?

It needs establishing why it has now starting tripping but on all evidence the existing transformer has been overloaded so yes a higher rated transformer should be your answer.

brianmoooore · Jan 3, 2022

If you are saying that it is behaving differently from when you first started using it, then something has been damaged, which could be either your transformer or the motor.