power requirment

[mamz2006]

Hi everyone,

I am planning to open small factory that uses motor driven machinary totaling about 300 hp motors.

My question is what appropriate voltage supply from utility company will be more effecient 380v versus 480v in 60hz power system and why?

apprecite your input.

regards,

 

[mdshunk]

I'd say 277/480, since 190/380 is usually a European voltage that you'd have a hard time getting served with here in the states.

 

[augie47]

effecient

effecient

As Marc says, if you are U.S. based 380 would be hard to come by utility wise.
I struggle with the term "effecient" a bit... as far as power cost, I don't think it would make a difference. As far as installation cost, it will depend a lot on the rated voltage of the equipment (as to the need for transformers, etc.; is the equip already wired for a particular voltage??). At 300 hp, my feeling would be, again as Marc says, 480/277, but again, the machine specs might make a change.

 

[mamz2006]

Thanks a lot Mark and augie47 for your inputs,
NO, I am not in US, so utility supply is not a point
augie47, I meant by "effecient" in power distribution and protection
Thanks again

 

[Jraef]

You need to really ask your local utility. They will not have 480V available if you are outside the US, just as ours do not have 380V available. If you have to buy a transformer, there go your efficiencies out the window.

In some non-US countries you may have an option for 690V, but the problem with going that route for something with only 300HP total load is that all of your switchgear and control equipment will cost more and be harder to find replacements for.

My advice would be to stick with whatever is the predominant industrial voltage at your location. Local suppliers will have equipment on the shelf to support and service you, the utility will have people knowledgeable in that system, etc. etc. Choosing something odd-ball is asking for trouble down the road.

 

[haskindm]

Remember that you are not billed for volts or amps, but for watts. Your motors will use about the same wattage for a given horsepower regardless of the supply voltage (as long as the motors are supplied with the voltage for which they were designed). It is a common misconception that your electric bill will be lower with a higher voltage. With a higher voltage, your amp draw will be lower, but your wattage will be the same. Lower amperage may allow for reduced installation costs (smaller conductors, less voltage drop, etc) but this will quickly disappear if your equipment is not designed for the supply voltage and you need to set transformers to supply the voltage you need. Determine the voltage that your equipment will use and see what the power company will supply. The choice will usually become obvious.

 

[kingpb]

If the largest motor is 300Hp, that is approx. 225 kW. A 380Y/220V system should be capable of adequately providing the power needed. If the motors toltal 300Hp, then 380Y/220V is more then adequate.

This should also be within the manufacturers normal scope of supply. Going to a higher voltage would most likly add addtional cost for the motors, due to non-standard design. I would be more concerned with efficiencies of motors supplied.