Conversion of 3ph generator output back to a single phase

[patracy]

I realize many of the military gensets can be reconfigured at the head to single phase. I've got a DRASH trailer, but as I understand, it will not easily be converted to single phase without causing some grief due to the control side of it.

What I wondered is if anyone here has employed two buck transformers in a open delta configuration to balance the load of the 3 phases to something more useful to a household single phase setup.

 

[WWRD99]

I realize many of the military gensets can be reconfigured at the head to single phase. I've got a DRASH trailer, but as I understand, it will not easily be converted to single phase without causing some grief due to the control side of it.

What I wondered is if anyone here has employed two buck transformers in a open delta configuration to balance the load of the 3 phases to something more useful to a household single phase setup.

I wish I could help!! There is a company down the street from me that plays with them. They make the AC systems for them and other mobile AC systems the military has. I am not sure if they are messing with the gensets but I can ask them.

 

[patracy]

You can ask, but I'd be certain if they're building the HVAC side of it, they're only interested in the 3ph power from the genset. I'm trying to devise a way to have a easily "switched" output from 3ph to single but still retain the HVAC/3ph if/when needed.

 

[WWRD99]

You can ask, but I'd be certain if they're building the HVAC side of it, they're only interested in the 3ph power from the genset. I'm trying to devise a way to have a easily "switched" output from 3ph to single but still retain the HVAC/3ph if/when needed.

I hear that! They build all kinds of stuff. The tents that hide the drones in the desert etc. There could be a guy there that does play with the genset side. They have multiple ones sitting out back plus empty trailers.

 

[Guyfang]

Whats the model of Drash equipment? There is only about a million different companies that supplied them to the Army.

 

[patracy]

I'm thinking something more agnostic that wouldn't require any changes to the gen head configuration or ECU. Simply tapping out of the leads from one or more of the breakers to feed into a pair of buck transformers in open delta that then you'd establish another breaker box setup.

 

[87cr250r]

Are you trying to power an existing panel? If no, there are panels that can be supplied with 3 phase power and provide single phase output. These would typically be fed with 208Y/120. You do have to do some planning with regards balancing if you want to run close to the generator's rated output.

NQ442L4C - Panelboard interior, NQ, main lugs, 400A, Cu bus, 42 pole spaces, 3 phase, 4 wire, 240VAC, 48VDC | Schneider Electric USA

Schneider Electric USA. NQ442L4C - Panelboard interior, NQ, main lugs, 400A, Cu bus, 42 pole spaces, 3 phase, 4 wire, 240VAC, 48VDC.

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You could also rectify to DC and power an inverter with that. Rectifiers are cheap to build. 6 diodes.

 

[patracy]

No, that wouldn't address the concern of balance. And rectifiers would produce a unclean output.

I'm thinking two buck transformers wired in the way the power company would wire a 3ph run into a single phase open delta setup with two transformers.

 

[sbgarage]

What all are you trying to power? Feed your house with two phases?

 

[patracy]

Yes, that'd be the primary use of it for me. Yes, I could try to run cords off and load other things exclusively to the 3rd phase leg, which I've tried to do as well. But in my mind, I'd rather employ two transformers in open delta to simply tie that 3rd leg in and get the single phase output most houses use. I've got a few isolation transformers from broadcast gear I might use as a test of this but I'll have to take them apart to see if they're 120v or 240v capable.


Think of it this way, I'm wanting to build a module that I can plug into one of the outputs like J3 or what have you, that feeds the two transformers, that then feeds a small sub panel/breaker setup to output either a single 240v output I can then route back into the house over a transfer. Or maybe even break that down into a panel with multiple circuits with a 240v outlet for transfer along with 120v service outlets. Probably just the 240v output is all that's needed since there's already 120v service outlets on the genset already. But care would need to be taken to not interconnect devices from those outputs to the outputs of those on the conversion side due to potential differences of course.