MEP 804A1 hook up questions

[Lmtv772]

I have a MEP804 and talking to a neighbor of mine , he said I don't have to worry about just hooking up two phases to my receptacle when I try to run the house.
Remembering that the load should be balanced between all 3 phases made me PM one of our resident Gen Set guys.
He suggested I should write a thread and see what you all can come up with as far as suggestions is concerned.
I wonder if there is a way of making a box or buying a converter that spreads the load of 3 phases evenly between two, I can use to run the house with.
thank you all in advance

 

[DieselAddict]

There is no simple or cost effective way to convert 3-phase to split phase. No magic box I'm afraid.

You can run the house on 2 of the 3 phases but I would recommend not running it to full load that way. You'll need to de-rate the generator by 1/3rd since you are only using 2 phases then by an additional 15% to keep temps in the alternator reasonable for the 2 phases being used. That basically means you won't get as much power out of it as you will get out of a 803. Your limit will be about 8kw.

 

[Suprman]

He is correct. A 3 phase generator is just not compatible for basic home power use. The 10k gen works very well though. You can set it for 120 or 120/240 single phase.

 

[Lmtv772]

I understand that, I just don't have a 10k gen

 

[Suprman]

You have everything else though.

 

[kloppk]

Remember you'll only be getting 208 volts and not 240 volts.

 

[Suprman]

Its 120/208 3 phase there are 2 120v legs you can tap off.

 

[Lmtv772]

Its 120/208 3 phase there are 2 120v legs you can tap off.

can you explain how you mean that?

 

[DieselAddict]

Each phase is 120v to neutral.

But since the phase relationship between any 2 legs is 120 degrees instead of 180 degrees for split phase, the voltage is 208v instead of 240v.

 

[Lmtv772]

According to this guy it wouldn't be a problem.
https://m.youtube.com/watch?v=d1quMdHegn0

im not that electrical smart and between what you guy's tell me and things I make out of them , I still scratch my head .
From what I see in this video can I not make a connector box and plug I'm the three phase and use for 120v?
https://www.youtube.com/watch?v=URuBaLbqATY

Would that not balance the 120v on all 3 phases?

 

[Lmtv772]

How about using a transformer? has anyone ever done that?

Diesel addict you said there is no simple way. how about the complicated way? how would that plan out?

 

[Suprman]

The easiest complicated way is a motor generator. Its a gen head on one end and an electric motor on the other in place of an engine on a standard generator. You would get one with a 3-phase motor and run that off the 3-phase gen. It would have a single phase gen head spun by the 3-phase motor. If it was me I would sell the 15kw 3-phase gen and buy a single phase gen. You would probably come out ahead a few bucks.

 

[Lmtv772]

The easiest complicated way is a motor generator. Its a gen head on one end and an electric motor on the other in place of an engine on a standard generator. You would get one with a 3-phase motor and run that off the 3-phase gen. It would have a single phase gen head spun by the 3-phase motor. If it was me I would sell the 15kw 3-phase gen and buy a single phase gen. You would probably come out ahead a few bucks.

how about a transformer?

 

[Suprman]

A transformer can be used to step up or down voltage but not change phase. There are electronic phase changers but they are very expensive. Anything is possible if you throw enough money at it.

 

[Lmtv772]

A transformer with a dual winding on the primary and the secondary that is wound for 480/240v (primary) and 240/120 (secondary). So by running the primaries in parallel and the secondary in series wouldn't you get 240v in and 240v out. and since the secondary would be run in series where the two windings connect together wouldn't you get your center tap? So one side and center would be 120v , the other side would be 120v and the two outside legs would give you 240v... and I thinking this wrong?

 

[Suprman]

You already have two 120 volt legs and a 208 leg. The 208 leg would be unused creating an unbalanced load. It wont work this had been covered over and over. The motor generator is the only realistic way to do it. Thats what the military does often when they need 400hz power for aircraft ground power. Big white or grey units convert 60hz 3phase power to 400hz for aircraft use. Same principle though.

 

[DieselAddict]

It can be done with transformers. You are looking at an expensive transformer. You can do an open delta transformer and get about 80% of the generators rated load out of it. It will still be an unbalanced load on the generator head BUT it will be more balanced than running 2 phases alone. Again your 15kw generator will be derated to about 12 kw. This will be a multi-thousand dollar solution unless you can find a used one.

As mentioned in a post above a rotary phase converter will solve the problem. Alternatively you can do a solid state phase converter. You won't get either of these options in a size to give you more than 10kw for under $2500.

It can be done. It will be a challenge to do it for a cost that rivals buying a single phase generator. Assuming selling the one you have and buying the one you need.

 

[Guyfang]

Whenever we need something "different", we always went with the motor generator. On our HAWK Air Defence Tactical Missile Site, (TAC-Site) we needed 416 volts, 400 hertz, three phase power. So we had two humongous General Electric motor generators. We then converted the german power, 220/400 volt, 50 hertz, three phase power to our required voltage. In the end, probably the best way to go.

 

[m109a2]

If I was your call the local industry like chemical plants,refineries,Ask for the electric shop and hmic and if you are a vet chances are he will help you. Tell him your needs from 208 3 phase to 240 single phase.Al