Military Diesel Generator

I strongly disagree. This is a three phase generator not a split phase. There is no center tap available in the generator windings. Attaching this 240V configuration directly to the house load will safely drive only 240V loads but not evenly split the voltage to each leg. An uneven load distribution of the 120V circuits will produce wild voltage fluctuations from 0 to 240 depending on what is connected and ON in the other leg. Now a properly sized transformer could take this into a split phase system. Proper loading concerns should be

The OP should hire an electrician to do this installation. There are several critical things that must be done to properly isolate the load and generator from the grid when grid power drops out and comes back. Circuit protection must also be satisfied, not to mention local codes and inspections.

Based on the drawing, I can not make a decision. It is not clear enough. It appears to be a 3 phase Delta output. I need a much more clear diagram/drawing to really make a full assessment on this one.

This is a 3 phase generator but you want 120/240 single phase. There may be clever solutions but I would be tempted to use a straightforward method that requires 2 single phase transformers.

You can get 240v single phase out of your generator with appropriate connections of the windings.

If you put this into a special transformer that is wound 240V primary X 240V/120V center trapped secondary you would have the voltages you need. However, I've never seen a transformer of this type. But you can rig the same thing up by getting two common single phase transformers of 480V primary x 120/240V secondary.

Hook one up "backwards" where you put the 240V from your generator into the transformer. You will see single phase 480 on the other side of this transformer. Feed it into the 480V side of the second transformer and you will get 120/240 single phase out of the other side of the second transformer. This is straightforward and simple to do.

These small transformers are sometimes called "lighting transformers" and are very common in the small sizes of 5 and 10KVA. You should be able to find a couple of used ones very inexpensively.

You will need a transfer switch and some other circuit protection fused switches depending on your particular electrical jurisdiction. If you are out in the sticks and are going to do it "seat of the pants" you still need to be aware that your little generator could backfeed the power utility without a transfer switch. That could zap somebody who hasn't done his safety procedure of shorting/grounding all the powerlines before working on them. (A school buddy lost his lineman dad to this exact thing many years ago when I was a kid.) So you want to be absolutely sure you are disconnected from the outside world before you kick in your little generator.

Hope this helps. Stay safe but don't let the safety Nazis kill you!

Jon.

You will NOT be able to get the type of power you want unless you use a transformer on one of generator's phases (it's a 3 phase gen) and convert to 120/240 split, but 3KW it will not be. You could get a bit over 1KW continuous or close to 2KW if you use two phases connected in star with a custom made (expensive) transformer, but I doubt generator will survive the thermal imbalance for long. S.M.

Better, give us the link where you found it

The operator manual is at
http://battlegradeelectric.com/manuals/TM-5-6115-615-12.pdf

and the diagram is on Page 4-3. The bottom right circuit shows the windings in series to produce a single-phase 240V supply, according to the caption. What is wrong with connecting this both to the household 240V line and to a 240V/120V stepdown transformer to supply the household 120V requirements?

The very first page of the manual says 120/240 single phase right in the heading.

Now that I can see it in detail their schematic is labeled wrong and most likely also incomplete. L0 should be connected to the same point where T3 and T5 connect to each other.

Thats all there is to it. No need to over complicate things for no reason.

Facts trump theory. GA.

Jon.

tcmtech,

You'll find, attached, a hand drawing of the connections of the stator coils to the L0-L3 outlets.

I wonder if it is possible to get the 120/240 split out of ALL stator windings, I wouldn't like to use the Y-120V with ground, and loose some power.

Already covered how to do it in post 2, 8, and 10. I can't make it any simpler.

L0 needs to be connected to where T3 and T5 meet. That effectively sets it up with the proper center tap on the 240 VAC single phase output so that you have your correct 120 - 0 - 120 output using all of the windings equally.

You are right, from your "terminal" everything looks simple. My problem is that I've got the "enemy combatant" manual! If I fallow the connections according to the tables, they don't match the diagram for the 240V single phase in this manual!

Tell you what! I am going to check on the generator if the T3 and T5 are connected with L0 when the voltage switch is on 240V single phase. If not, I will look for the voltages to get the 120V 0 120V.

I kept asking because I didn't see that phase 1 and phase 3 (on the diagram) are connected with opposite polarities, and (I take your word for that) will create a component of the same magnitude but of opposing phase with phase 2, hence, the 120-0-120 split.

Thank you, you are a prince!

The .pdf copy of the manual was much easier to see (making my earlier post OT). Check carefully the instructions for grounding this unit, which depend on the voltage configuration you select. I think one of these grounding arrangements does the L0-T3-T5 thing. It is also recommended that you start the unit only with the load connected. This seems to be a very versatile design. Please keep us posted on how it all works out.

They have, for 240V single phase, the grounding on L2. That would be stupid, for me, to use this way. The recommendation is for single phase 240V. There is not other mention for grounding 240V, but because the house has the ground between the two 120V, I will ground L0, connected to T3 and T5, to ground.

Hopefully that will do it!