MEP-804A single phase 120/240 conversion issue

[Guyfang]

Well now I am confused, that needs no response however. But seriously, I thought the 804A had all 12 leads being brought out, it was only the 804B that moved to 10 leads being brought out .. Thanks in advance .. mac/mc

The only difference between a MEP-804A and MEP-804B, is the engine. Folks, read the TM. All your questions are answered in the TM's.

 

[Demoh]

All of the units above the 10kw MEP803 are 10 wire heads.

Well aint that a stinker. To some (most?) people a 12wire is gold and a 10 wire is nothing more than a rotating paperweight. I have a 40kw NG/LP gen that is a ?? wire that is 120/240 single phase only which is useless to me.

I guess its up to anybody that wants singlephase to pull those leads apart. I am very curious if that is possible without visiting a motor shop.

 

[DieselAddict]

I've been wondering the same. I don't have access to one to check out. It will take a bit of disassembly to get the alternator off to check. It would be ideal if someone had a spare stator and could do some investigation. You can look at it without pulling any wires apart. If the joint isn't readily visible it won't be easy to modify anyway.

The previous generation machines are 12 wire heads. (MEP004, MEP005).

 

[doskiez]

If your charge controller can accept a decent sized DC input I would vote for a mechanical rectifier as a simple solution if you can find an appropriately sized 3 phase motor and DC generator. Might look at an old welder for the generator and a lot of industrial machinery run large 3 phase motors that most consumers cant utilize. then you could make use of the 3 phase output for future machinery needs and single phases for other small loads while battery charging. Just a thought, I have been looking at generators recently, I would like to get an 803a for backup power and for off grid use.

 

[Guyfang]

You guys just need to move here. Everyone has three phase. Sooooooooooooooooooooooooooooooooooo simple!

 

[Demoh]

You guys just need to move here. Everyone has three phase. Sooooooooooooooooooooooooooooooooooo simple!

Stop making me jealous.... the power company wants to charge me $4800 to upgrade the service from 150A single phase to 400A single phase.... Thats because im at the end of the line so Id need my own transformer. Great no problem, but the current pole is a 4' neutral instead of a 6' neutral so I have to get a new pole on my dime. Great. If I wanted 3 phase they would have to upgrade each upstream pole to the main road to the tune of $9000 each and thats 4 poles. Thats like $40000 they want....

So If I want to run my milling center (nameplate 25kva 3ph 208, 60a breaker) I have to cringe whenever the contactor initially closes to charge the caps in the drive controller, it makes my 3ph idler motor that generates my 3rd leg jump off the floor an inch.

Ive considered running it off a MEP but the only TRUE 3phase loads on the mill are the 2 coolant pumps, the chip auger, and the cooling fan for the spindle. Everything else is single phase or is a 3 phase bridge rectifier to a bank of caps which it inverts (like how the 831s work)

 

[155mm]

What about a phase converter?
like this

https://youtu.be/ZqnfLHhuuUQ

 

[Demoh]

What about a phase converter?
like this

Well isnt that cheating, I like using a rope to start my 16,000lb milling center using the 5hp idler I have.

I do have a rotary phase converter for it but havent hooked it up since moving. been too busy rebuilding gens lately.

 

[kavesman1]

Stop making me jealous.... the power company wants to charge me $4800 to upgrade the service from 150A single phase to 400A single phase.... Thats because im at the end of the line so Id need my own transformer. Great no problem, but the current pole is a 4' neutral instead of a 6' neutral so I have to get a new pole on my dime. Great. If I wanted 3 phase they would have to upgrade each upstream pole to the main road to the tune of $9000 each and thats 4 poles. Thats like $40000 they want....

So If I want to run my milling center (nameplate 25kva 3ph 208, 60a breaker) I have to cringe whenever the contactor initially closes to charge the caps in the drive controller, it makes my 3ph idler motor that generates my 3rd leg jump off the floor an inch.

Ive considered running it off a MEP but the only TRUE 3phase loads on the mill are the 2 coolant pumps, the chip auger, and the cooling fan for the spindle. Everything else is single phase or is a 3 phase bridge rectifier to a bank of caps which it inverts (like how the 831s work)

That's pretty expensive. I'm still looking into building my shop, but the local power company quoted a price of $500 for the 3 phase hookup to my lot next to the house. But still not sure what the monthly contract cost will be yet. But I've also looked into different options.There's a company call Single Phase Power Solutions. They make very large single phase 240/480v motors from the 15hp-100hp range. You could use their motors coupled to a 3 phase genhead to get clean 3 phase power to your equipment.

 

[Demoh]

That's pretty expensive. I'm still looking into building my shop, but the local power company quoted a price of $500 for the 3 phase hookup to my lot next to the house. But still not sure what the monthly contract cost will be yet. But I've also looked into different options.There's a company call Single Phase Power Solutions. They make very large single phase 240/480v motors from the 15hp-100hp range. You could use their motors coupled to a 3 phase genhead to get clean 3 phase power to your equipment.

The reason its so expensive is because my lot is already developed (house built 40 years ago) so I dont qualify for the new service discount. If it was an undeveloped piece of land it would be much much cheaper for the single phase (Im sure they would still charge me for the 3 phase)
My applications having clean 3 phase isnt really a need. Im at the stage where I dont mind a few extra steps to start making chips with the mill.

 

[Buster1528]

The why is because three of the windings are premenantly joined in a {edit} Y configuration inside the head. That locks you into delta only operation.

What I've wanted to see is how possible it would be to trace wire 10 back into the generator head and find the connection point where the three windings come together. If that joint is accessable without a lot of trouble you can convert it to a 12 wire head.

I have a 1994 Libby 804 A it has 12 wires coming out generator. Why would it have 12 if most 804 A are only have 10?

 

[DieselAddict]

Two of the wires are for the exciter. Only 10 provide power.

 

[Cdavis370]

You might try finding a 416V 3-phase to 120V 3 individual secondary winding transformer, or alternatively 3 individual 416 to 120 volt transformers. From there you can make a zig-zag connection to get real 120/240 single phase power. I did this on a much larger (100Kw) gen set using 3 individual 440 to 120 transformers.