Three phase or single?

[MagicNC]

I'm building in a commercial area and my neighrbor has three phase power. Should I go with three phase or single phase? I will probably running a compressor and a plasma cutter in the future.

I am thinking three phase will be more economical in the long run.

My heat, hot water, and range are natural gas.

 

[Techie1961]

Not sure. If it's just for a compressor, I probably wouldn't do it but if there is any chance that you will add other machines, do it. Three phase is much more reliable for machines but for welders, it doesn't matter as they are usually single phase.

 

[930dreamer]

X2 on your future plan for three phase equipment.

 

[manwithtools]

Three phase is great and will save on everything from motors to wire size (assuming the three phase is more than 230 volts) - although you will need four wires in each circuit and not three.

It will cost more for electrical distribution panels and you may have a monthly minimum charge from the electric company for three phase. The ability to run whatever size motor you need may be of value as well in the future.

 

[sberry]

Agree, if you want to be a compulsive collector of old machine tools from auctions from machine shops then 3 is for you if the price is right. For common stuff especially if you want it to be fluid then single with up to 50A for tools is for you. Other than a 300 synch I never use anymore don't own a single other thing that would overheat a number 10 wire.

 

[sberry]

I am thinking three phase will be more economical in the long run

Not for home type use, the duty cycle is so short and one is paying for watts there is no savings. If you were a foundry smelting aluminum yes, pumping large amounts of water for long periods etc.
The only real benefit for the small user is the old tools can use it, they are cheap and plentiful. You could buy a world class compressor for a shave on the dollar of new. Mills, lathes, welding machines all the same. Wont save any real money running them.

 

[wyliesdiesels]

I'm building in a commercial area and my neighrbor has three phase power. Should I go with three phase or single phase? I will probably running a compressor and a plasma cutter in the future.

I am thinking three phase will be more economical in the long run.

My heat, hot water, and range are natural gas.

I would go with 3-phase if its available.

However it wont be more economical. It will most likely be more expensive as there is demand charges and peak/TOU rates associated with 3-phase services.

What voltage 3-phase can u get?

If its 480v then u should hire an electrician. 480v is NOT a DIY voltage.

Not sure. If it's just for a compressor, I probably wouldn't do it but if there is any chance that you will add other machines, do it. Three phase is much more reliable for machines but for welders, it doesn't matter as they are usually single phase.

Actually u can get welders that have 3-phase input.

Three phase is great and will save on everything from motors to wire size (assuming the three phase is more than 230 volts) - although you will need four wires in each circuit and not three.

It will cost more for electrical distribution panels and you may have a monthly minimum charge from the electric company for three phase. The ability to run whatever size motor you need may be of value as well in the future.

3-phase 240v uses less amperage than single phase 240v so u can use smaller wire even with 3-phase 240v.

 

[sberry]

I might do it because I can, because someone gave me a 200A panel. As the OP only barely mentioned the purpose and existing conditions, the rest is pure speculation. While some things can be done, some ideas are good for some people it doesn't always match the need.
Single is easy to move, simple to wire for with common materials and common circuits. A 5 hp comp will deliver air for professional as well as 50A welders and many new additional ones are in the 20A demand range, not even a speed bump.
Wire savings don't mean squat, need a whole nuther layer of junk sits idle for most people.

 

[sberry]

Its one of the things that has kept the 50A buzzer in the game is it is so fluid and runs from common service. The DC version in the same class has really given it some legs. I could have found a Dial Arc or Ideal arc but all my 10 cords become out of flavor to run the same rod anyway, 95% of the home hobby small biz work is done with 1/8.

 

[sberry]

If a guy needed continuous air pumped at high hp then again another matter but for common shop work not needed.

 

[manwithtools]

3-phase 240v uses less amperage than single phase 240v so u can use smaller wire even with 3-phase 240v.

Yes, correct. But it's still four wires vs three so real wire savings adds up with higher voltages.

 

[tfi racing]

I'm surprised that you have a choice in an industrial/commercial area,three phase is likely your best bet.How big is your building going to be?Also consider that it will be less expensive to do it at this stage,you will be paying a lot more later to add three phase power if you,a tenant or future purchaser needs it.

 

[Thumper68]

I would do it just for the equipment savings alone, the fact that you can buy used equipment for pennies on the dollar over single phase stuff.

In the last month I have passed up 3 compressors, 2 pedestal grinders and several wood working machines due to the fact that they are 3ph.

One of the compressors was a very nice 7.5hp dual motor, dual pump on a 100 gal tank still on the shipping pallet and factory wrapped, I could have gotten it for less than $300.

 

[Techie1961]

Actually u can get welders that have 3-phase input.

Yes, that's why I put in "usually".

 

[rockwithjason]

before you pull the trigger you had better understand your poco's billing structure. you may be floored at the additional costs if they allow three phase to a dwelling unit at all.

 

[bloomingtonmike]

There is always a solution to run single phase and use a rotary phase converter or VFDs when the need arises. I have 200amp single phase and panels for 3phse after a 20hp rpc. I also run 5 VFDs on various machines.

Three phase one site might help with resale of commercial property depending on what you are building.

 

[reader2580]

I would do it just for the equipment savings alone, the fact that you can buy used equipment for pennies on the dollar over single phase stuff.

I too see lots of used equipment that goes cheap because it is three phase.

I took home an old drill press from work when my employer moved out of our old building. I was shocked to see it was a 1/3 HP motor that was three phase! My friend still wanted it as he was able to get a single phase motor from a mutual friend.

 

[Norcal]

before you pull the trigger you had better understand your poco's billing structure. you may be floored at the additional costs if they allow three phase to a dwelling unit at all.

I would not want 240V 3Ø in a residence although it was common in some areas using delta breakers for air conditioning, the high leg is going to confuse DIYers, but having 3Ø does open up things in a shop. As said above higher costs could break the bank.