Higher Capacity Motor

Thanks buddy...

With the motor protection applied to protect the transformer, instead of the motor, it may or may not work, though it will be safe.

Transformers are rated lower than they are actually capable of for a margin of safety. Motors are rated higher than they usually have to perform in real life. This all has to do with safety but in your case I think your margins may overlap and you would be safe. Don't blame me if you blow your transformer though. It's your choice. If you decide to go ahead with this, at the very least, you should monitor the actual power being transferred to the motor for awhile to try to learn if this will work. The easiest way to do this is use a clamp on ampmeter to monitor the actual amperage and then calculate your horse power. I am sure that some of the math whizzes on here can provide you with formulas and details about how to do this. Just ask.

vivek; most transformers can take a 25% over load ,if you are worried put a cooling fan to dissipate the heat generated. perry

A good way to cheat the system is to power factor correct the transformer on the supply side and then further power factor correct the motor on the secondary side of the transformer. (standard issue AC power factor correction capacitors)

By reducing the VA load of the motor its apparent power Vs true power will become much closer. You may see as much as a 40% drop on the motors amp load at the transformer when done properly. That effect will free up considerable amperage capacity over head on the transformers windings. That will equate to a more efficient transformer too simply from less internal heating!

Doing it on the primary side of the transformer also will free up more line amp capacity on the primary feed source as well. Secondary side power factor correction does the motor. Primary side power factor correction does the transformer.

If properly done you may likely see a 50% reduction in the amperage drawn at the circuit breakers!

Your 30 hp motor could balance out as having the same apparent power draw as a 15 - 20 hp motor!

Yes, Mr. Vivek.

You can temporarily use with the following care. For that you have to study the actual temperature rise in your Transformer. If the actual temperature rise at 25 H.P and the max range permissible to be looked in to.

1. If the margin is narrow, you take steps to increase the cooling of the transformer, by providing additional cooling surface in the oil circulation and operate the transformer.

2. What is the power fctor in the system.If it is less take steps to improve thePower factor.

Provide the details to my mail sd610@rediffmail.com and I will study and suggest, if possiblhanks,

DHAYANANDHAN.S,

CR4 MEMBER,

INDIA.