MEP806A Double Delta Single Phase

[SandBar]

I see its a 12 lead alternator, any reason it cannot be wired in a double delta for 70% rated output in single phase?

 

[Scoobyshep]

Without being familiar with the specifics of that unit, You need to be aware of the sets controls monitoring and how the voltage regulator is being fed. why double delta and not a zigzag?

 

[SandBar]

In my limited knowledge it seems every alternator manual I read that has both zig-zag and double delta listed, they advise double delta and not zig-zag. Leroy Somers for example puts big bold text next to their zig-zag options "NOT ADVISED".

 

[MrMikey4026]

I wire my generators double delta for single phase. Never had an issue, but I have always tried to balance the loads.

 

[SandBar]

I wire my generators double delta for single phase. Never had an issue, but I have always tried to balance the loads.

Ever run a 60kw in double delta?

 

[MrMikey4026]

Ever run a 60kw in double delta?

I don't remember anymore, it has been a decade or so.
Was doing generators for Verizon, they ran a few 60KW.
I will have to ask one of my buddies that is still doing them. I just text messaged one of them, should have an answer soon.
Mike

 

[SandBar]

I don't remember anymore, it has been a decade or so.
Was doing generators for Verizon, they ran a few 60KW.
I will have to ask one of my buddies that is still doing them. I just text messaged one of them, should have an answer soon.
Mike

Did Verizon use surplus generators at times?

 

[MrMikey4026]

No, surplus ever. When I was doing them they were installing new Katolight units. Katolight was bought out by MTU years ago.
They did have Kohler, Onan and Generac. The Generac's were on older sites.
Whenever I had to work on a surplus military unit they were a mess. The control and safety systems were terrible.
I ran into a few at fire stations and military sites.
Mechanically they were very durable.

 

[SandBar]

I opted for an 806a vs a 806b for that very reason. Same power output, less to go wrong.

 

[DieselAddict]

Have you verified its a 12 wire head? My understanding is that everything 804 and above are 10 wire heads.

 

[Ray70]

Correct, 804 and up should be a 10 wire.... or that's what we've all been told for years.
The 004 005 and 006 can be reconfigured to run single phase at full rated output, but the 804 and up can not due to the last 2 wires being connected internally somewhere...
If I recall correctly, a member here was recently considering opening one up to see how that internal connection is made, to see if there is a way to reconfigure it or not.

 

[SandBar]

Have you verified its a 12 wire head? My understanding is that everything 804 and above are 10 wire heads.

wires t0 through t11 verified as existing in several photo galleries, and in about 4 hours I will re-verify in person.

 

[Ray70]

Keep in mind 2 of the wires are field excite wires, so a 12 wire head has 14 wires total, 12 fat power wires and 2 smaller field wires.

 

[DieselAddict]

I'm super curious about this possibility since the diagram in the TM shows it as a 10 wire head. There are 12 wires coming out but two are not load conductors. They are for the VR.

According to the diagram the load conductors should be T0-T9.

 

[SandBar]

Checked about 4 auction photos, and all boards have 4 white and 8 black leads that "appear" to terminate at the reconfiguration block. Hoping it is 12, if not will have to bring in help to figure it out.

 

[DieselAddict]

Three of those are OUTPUT wires. The ones on the left going to the contactor. They don't count.

 

[SandBar]

Good point, that makes it more interesting as I can't see 10 in any of the photos. I will have to get mine home and take some better photos. I reached out to the alternator manufacture to see if they had any knowledge to share about potentially re-configuring it.

 

[SandBar]

So the manual says single phase is possible in the default config. How much load could we pull in single phase and how balanced would it need to be? Trying to avoid getting a giant 3 phase transformer.

 

[Ray70]

Correct, you can get single phase easily, but would need to do some creative wiring to try to get even close to 60Kw out of it! You don't want to run that gen for long periods of time with very little load and you don't want to grossly imbalance one leg with all your load and nothing on the other 2.
What are you trying to power with this machine and it's 60+ Kw potential output?

 

[DieselAddict]

Can you describe the scenario? Is this emergency power or prime?