Running a 1250 on 408 volts?

[Oldsarge]

I'm getting my shop set up, and because of the service available, I may need to run my 1250 on 480v Will there be any changes to what type of consumables I use, and what gauge of wire is needed to make this run? Will be ~30 ft from the panel. I used an online calculator for the wire gauge and according to the length, volts and Amps, it says I can use 10 gauge wire!?!?! Something doesn't seem right about that... Any help very much appreciated!

Oldsarge

[SignTorch Vector Art]

One advantage of higher volts is that it draws less current per watt, less current means less wire heating, less heating means smaller wire is sufficient. I don't think supply voltage affects torch operation.

[Metal Lee]

The unit needs to be designed to run at 408 volts! Check the tag on it to see what it is designed to run at, 240,347,600 etc, if it is a 240v unit you can't just hook it to 408v you will blow it up! Check to see if there is a stepdown transformer or a lighting panel somewhere that has the voltage you are looking for and hook to that. Let me know how you make out.

[Oldsarge]

The unit needs to be designed to run at 408 volts!

From the users manual of the 1250:

The Powermax1250 is a universal power supply that can configure itself to operate with AC
voltages from 200 to 600

If I'm reading this correctly, the 1250 should automatically sense and adjust itself on single phase all the way up to 480 volts and can also run on 3 phase power as well. So I guess the voltage is self sensing, but should I jump up to a heavier gauge wire? 10 gauge supposedly work if you believe this calculator:

http://www.csgnetwork.com/wiresizecalc.html

Copper, single phase, 480 volts, Half circuit length I used 45' as a worst case scenario, and 80 amps draw.

I'm buying wire tomorrow for the majority of my runs. Copper is insanely expensive right now, and the best deal in town is Home Depot... I've had several electricians tell me that because they buy trailer loads of it that they beat the supply houses by a good margin. Add a 10% military discount, and I can get a 500' roll of 10 gauge for $108.00 I figure it's going to cost me about $850.00 to wire everything in the shop

Any input on the wire requirements for the 1250 would be appreciated... Thanks!

Oldsarge

[SignTorch Vector Art]

the specs say the 1250 draws 17 A at 480 V 3 Ph

at that rate, some charts say you could go 100 feet with 16 AWG, most suggest 14 AWG

on the link you mentioned, I have to enter 150 A load across 30 feet to require 10 AWG wire on 480v/3ph

here's one I like http://www.paigewire.com/calculatorinstructions.htm

I think 14 AWG is sufficient, 12 would be plenty, 10 may be overkill

[jimcolt]

If you are running on 3 phase 480 volt the 1250 will draw 17 amps per phase. You will need to run at least 12 gauge wire for this setup, and the wiring should be rated for 600 VAC.

If you are running on single phas 480 volts, the 1250 will draw up to 30 amps, so in this case you would need to use 10 gauge wire, rated for 60 VAC as well.

The Powermax 1250 auto detects the voltage and frquency, and will operate on any voltage from 200 to 600 volts, single or 3 phase. The higher the voltage , the lower the current draw and the smaller the conductor size.

Jim Colt Hypertherm

[SignTorch Vector Art]

To be clear: see below...

[redneckgateart]

Typically on a 480v, 3-phase service you'll have 277v, phase to ground and 480v, phase to phase. (480 / sqrt(3) = 277)
The only way to get 120v,208v or 230v out of a 277/480 service is to use a step-down transformer.

[Bigrhamr]

Typically on a 480v, 3-phase service you'll have 277v, phase to ground and 480v, phase to phase. (480 / sqrt(3) = 277)
The only way to get 120v,208v or 230v out of a 277/480 service is to use a step-down transformer.

That's what I ran into when building my new shop that I haven't got to move into yet. I wanted 3 phase and had a choice of 480 or 208. 480 sounds great until you look at needing step down transformers for everything except your high voltage 3 phase equipment, most of which can be wired for 208 or 240 3 phase anyway. I went with 208 and if I ever have a piece of equipment that has to have 480 I can just use a single step up transformer for it.

[Oldsarge]

Landlord is taking care of everything to the panel which runs everything up to 220v and is also installing a high voltage 480v single phase box as well... I should have plenty of power when all that is finished. Also has to upgrade the panel to 200 amp service with 40 circuits... just have to get in there and start pulling wire!

Thanks for the help!

Oldsarge