480-240-208?

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dwalker

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I have a question about what would be the best service size to go with.
here are the following machines all 3 phase
200amp 480
175amp 208
175amp 208
30amp 208
30amp 208
60amp 240 this is single phase
The 200amp 480 already has a 240-480 transformer.
I also need 120 for lighting
Thanks,
Doug
 
It depends on what you mean by best. Best in what way? The big question is what will result in the least number of transformers, etc. If most of your loads require 208 single or three phase and 120-volt lighting and receptacles, then that would be the "best" because you will not need to provide transformers. If most of your loads are 480, then that would be "best". You will also need to find out what the power company is able/willing to provide.
Also what may be considered "best" is the one that will cost the most to install. More cost = More Profit;).
 
dwalker said:
I have a question about what would be the best service size to go with.
here are the following machines all 3 phase
200amp 480
175amp 208
175amp 208
30amp 208
30amp 208
60amp 240 this is single phase
The 200amp 480 already has a 240-480 transformer.
I also need 120 for lighting
Thanks,
Doug
Click to expand...

I'm a little lost here. Do you have 480 available as a service voltage, or are you stuck with 120/208 and need to step it up to 480?

Without knowing what you need for a lighting load, we can't answer your question. Plus, if you have 480 volts for a service, you should consider 277v lighting instead.
 
dwalker said:
I have a question about what would be the best service size to go with.
here are the following machines all 3 phase
200amp 480
175amp 208
175amp 208
30amp 208
30amp 208
60amp 240 this is single phase
The 200amp 480 already has a 240-480 transformer.
I also need 120 for lighting
Thanks,
Doug
Click to expand...
Call the poco and work out a load letter to see but my guess is 600 off the top of my head.
 
The best case would be to see if the POCO will hit you with 480 wye and 208 wye. They'd do that for a big industrial customer, but I sorta doubt that they'd do it for your few machines. I'd ask anyhow, if for no other reason but to be told 'no'.

Lacking that option, I'd go for a 208 wye service, and see if the taps on your 240 to 480 transformer that the big machine has can be switched around to accomodate 208 on the primary side and get something closer to 480 on the secondary. With that option, all you'd have to buy is one buck-boost for your one 240 machine.
 
Sorry I should have given you more detailed info.
I'm moving to another building and the power company told me I have a choice of 208,240,or 480 3 phase service at no charge and I thought they said delta. All machines are 3 phase except the 60 amp 240.
I have one machine that I'm currently running that needs 480 and I have a 240 service with a 480-240 delta transformer already. I will have 2 more machines that need 175 amp 208volt and 2 pumps that need 30 amp 208 volt. I also need a 60 amp 240 single phase for another machine which won't be running that often. The lighting is 120 volt fluorecence. Hopefully this is the info needed to give a proper answer.
Thanks so much,
Doug
 
I'd vote with mdshunk. Your transformer probably has taps that can get you close to the 480 you need. The 208 will provide almost all the rest, and chances are the 208 is 208Y/120 so your 120 needs wo0uld be met.
The 240 machine is all that is left and if it's critical, a buck & boost should take care of that.
 
Ok the electric company said I can have anything I want for no charge.
480 delta
240 delta
208 y
Do you all still stand with your previous choice?
Also will 600 amps work or is it borderline and I might need 800 amps.
Thanks,
Doug
 
dwalker said:
I have a question about what would be the best service size to go with.
here are the following machines all 3 phase
200amp 480
175amp 208
175amp 208
30amp 208
30amp 208
60amp 240 this is single phase
The 200amp 480 already has a 240-480 transformer.
I also need 120 for lighting
Thanks,
Doug
Click to expand...

will the 208 v machines can be reconfreaged [ changed ] to 480 volts ??
if so it will be somehow eaiser to get the system hook up like that for the service size i will go with 800amp service @ 480 wye system IMO this way if you need 120 volts for genral lighting circuit you can have 480-240/120 single phase transformer for this and can included with the single phase machine you mention there.

Merci, Marc

P.S. just becarefull with Delta system each one have it own achress heel with it.
 
Hi Marc,
Unfortunately the 2 machines that are 208 can not be changed to 480 but i think the 240 single phase welding machine can be changed to 208. I'm looking into that now. I've always wanted 480 because different machines I come across are usually cheaper since a lot of people can't get 480.
Regards,
Doug
 
Are you certain that the 208 V and 240 V machinery are limited to those voltages?

Some machines are rated to run on 200 V to 240 V.

If the 240 machines can run on 208 V or changed to 208 V than a 480 V main service with a tranformer to 208/120 V Wye system looks ideal.
 
Hi Southpaw,
I know the machines running 208 and 480 cannot be changed.
The 240 machines are possible. Thanks for replying.
Regards,
Doug
 
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