Single phase and three phase out of a mep006a

[WILLYSOVERLAND]

I have a gen set for sale and a customer asked me if i can get 480 volts three phase, and 220 volts single phase at the same time.
I told him I should be able to get it I just didn't know how at the present time. can somebody explain it to me?
i saw a wiring diagram for getting 480 volts three phase out of a 12 wire generator so I have that covered ( i know i would have to re configure the wires). Do one of you guys have a diagram or any experience with this? Thanks in advance. willys

 

[Triple Jim]

480 phase to phase would give you 277 neutral to one phase. It sounds like the only solution is to get a transformer and have 120/208 from that, or 240 without 120 if that's needed.

 

[Poccur]

In a high zig-zag single phase you get 240 and 480 ...do you have access to the head of the generator? What make/model is the generator portion of the 60kW ? Marathon?

 

[Isaac-1]

You are never going to get true single phase and 3 phase out of the generator at the same time, the closest you can do is put a step down transformer on one or two of the legs, doing this will only allow you to draw a small fraction of the total output in single phase though (think of a situation running big 3 phase motors, but also needing a couple of KW worth of 120V single phase for control electronics, lighting, etc.) The exact balance of single phase to 3 phase that you could provide would require a fairly advanced site survey and should be left to the professionals, as it is really beyond what is practical to get into on a message board such as this one.

Ike

 

[WILLYSOVERLAND]

I think its a GE or Westinghouse 12 wire brushless generator. The tag states 208/416. I looked it up on the net and i am almost positive i can get 480 out of it by connecting 4&7, 5&8, and 6&9. I also get that two legs =277 volts. The customer wants to run a 480/3 phase motor for a concrete grinder. He also has some use for 220/1 phase at the same time. I don`t want to just tell him "yeah you can get both" without doing some homework. Unfortunately the sale hangs on being able to get both from the same unit at the same time. here is a link to the tag on the generator. Maybe the storm blowing in on the east coast will help move the genset.
http://www.deadzoom.com/member/emory/195.JPG

 

[Isaac-1]

The thing is NO GENERATOR will deliver both at the same time, the best you can do is add a step down transformer to supply your single phase load, but you need to make sure this will not eat into your available 3 phase too much. The problem being is you loose 2 - 3 times the 3 phase capacity as you use in the single phase connection. In other words if you need 5 KW worth of single phase power, you could eat up close to 15KW worth of your 3 phase capacity getting it.

Ike

 

[Triple Jim]

As stated, a transformer is the only way to get something good enough to do what is needed. When wired for 480 phase to phase, the 277 comes from neutral to one phase, not two phases. In this link http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&ved=0CIwBEBYwCQ&url=http%3A%2F%2Fwww.pioneerelectric.ca%2FProducts%2FDryTypeTransformers.pdf&ei=ZauJULapDrKs0AHmg4CIBQ&usg=AFQjCNEm0w5rgbnDivK5L1Z1UPkzIlh_xw on page A2, there is a column for transformers that go from 480 delta to 208/120 wye. If you used one of these, for example, you'd have 480 3-phase, and could get 208 and 120 from the transformer. By balancing the 208/120 loads on the three legs of the transformer output, you can keep from losing excessive 3-phase capacity. Since most 240V equipment runs fine on 208, your guy gets what he needs. Other than going to an inverter of some sort, this is the only way I know of.

 

[Isaac-1]

Jim, the key to that statement is MOST 120/240V single phase equipment works fine on 120/208V 3 phase, without knowing more about the situation it is easy to give bad advice.


Ike

p.s. also in mixed environments such as this you have to be VERY careful on grounding, also there is concern about delta vs. wye transformers and circulating currents.

 

[Triple Jim]

Ok, true. I will add that unless WILLYSOVERLAND fully understands all the ramifications of using the transformer, he should get help from a qualified electrician or similar, should he choose to go that route.

 

[Poccur]

I would reiterate that the high zig-zag is single phase.

FYI, the square root of three (or approx 1.73) is a handy number to remember when talking about this king of stuff. If you know the three phase voltage of a system, divide by 1.73 to get the single phase. If you know the single phase, multiply by 1.73 to get the three-phase. Just a handy reminder method to keep in your head.

 

[truckdude22]

I have welding rigs, big tig and stick ones that have 4 pin connectors but they're single phase, think a mep 006a would run them? Transformers are expensive.

Can you ground a generator to your truck? I saw someone running a gen on YouTube in a parking lot on a truck...I've heard you need to be down deep with your grounding rod.

Finally, anyone know the noise levels? Really loud?

 

[brianrbull]

if they are single phase 110 and you run one on each leg to balance the load I dont see why it would not work... what you want to avoid is a load imbalance , Grounding to your truck would not work unless you grounded the truck to earth... and yep the 006 is a beast, Loud and Proud. I love mine, power for days....

 

[truckdude22]

208-230-460v. A generator specialist explained running on each leg I don't understand the concept at all could you elaborate? How far back would it need to be for hearing damage not to occur? Been reading about low frequency. Also, if I built a box around it and opened one side, the side I'm not operating on for air flow, and it were the size of a deuce bed, 8x 12, giving it breathing room think that might work? I was thinking about using radiator fans on top to push air in. If I had six or seven high output fans on top and 2 feet of breathing room on each side could that work? Thanks!

 

[truckdude22]

Think the gen is overpowered? I've heard the 30kws would be enough but the gen expert said if I'm pulling 100 amps I need at least 40kw. I know they're underrated but I don't want to overdraw. I also don't want to tax machine on a high frequency start up.

 

[WILLYSOVERLAND]

most single phase welders draw about 100 amps at 230 volts single phase. I run mine on a 30 amp breaker in my garage. I never tried to weld at 500 amps with it but anything (generator) that puts out 50 amp @ 230 volts should run that welder but like I said I don't think it would run well at the top of the dial setting. high frequency on a tig welder hardly uses any amperage. I wouldn't give that a second thought. most welding jobs are small thin metal any more. they don't make thing with thick metal like they used to.

 

[truckdude22]

Your numbers seem spot on. The stick start up is high, I was under the impression the tig 250 idealarc would draw high amperage. I have thick metal work to do. Do you think the 006 is too much? And I saw a post reference about swapping it to single phase but couldn't find the full posting. I've heard sometimes it works sometimes it doesn't.

 

[truckdude22]

Does the 006 push out more than fifty amps?

 

[brianrbull]

MEP-006a is a 60kw 225 amps per leg (x3)... so yes a wee bit more than 50

 

[Jbulach]

You need to go by your input amps plus volts on your welder equals your watts. The largest typical single phase welders are right around 50A max at 230V = 11,500.
I don't think you're your going to have to account much for your strike surge with 5 welders not likely starting at the same time.
A 15kw generator should be more than sufficient for and one welder.
Guessing your genny is slightly underrated anyhow


M925A2 with dump hoist

 

[truckdude22]

http://www.ebay.com/itm/Idealarc-Ti...6fc396&pid=100338&rk=7&rkt=17&sd=301704738768

At 230 that's pulling 130 amps. That's a big boy but most are up at 90. I'm confused is each leg 225 giving mid six hundred amps or is that what each leg equally share and is total output? Yes I would like to run two machines simultaneously if possible. Three would create too many fluctuations, it would seem hard on the generator unless someone can explain this one machine on each leg thing to me.