# New guy with a 4K Homelite - I want to rewire the head.



## JayArr (May 3, 2021)

Hi All

My name is Jeff and I've got a working Homelite EHE4000CSA (UT -03647). I don't find much info on it on the web but it's a standard B&S 8HP motor and the head was configured for 120 and 240VAC. It's 4000W peak, 3600W running so it's 120V-15A times two with a center neutral.

I need 120V 30A for my travel trailer. I thought it would be a simple task to pull the end cap off and swap the wires around from series to parallel and then wire it up to a travel trailer socket (TT-30R).

Unfortunately I found a much more complicated wiring scheme and need some help deciphering it so I don't smoke the windings.

I found that the head terminated in 5 sets of wires, they were crimped into ring connectors but then just shielded over and tired into the windings. On my diagram I've labelled them A-E. I get 120V from A-C and from C-E and I get 240V from A-E. B and C didn't go anywhere else, they were just ways of tying the windings together. I've also labelled the four wires that go to C as C-upper and C-lower.

So here's my question. Can I separate the wires at C and connect C-upper to E and C-lower to A? That puts the windings in parallel and should give me 120V at 30 amps right?

What does that do to B and D? They seem to be feedback to the AVR, will their polarity be OK if I do that or do I have to pull B or D apart and swap the polarity of one of them?

JayArr

PS: I'm also converting it to propane but I'll make a separate thread to share my install notes.


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## tabora (Sep 6, 2018)

On a 240V generator, the two 120V legs are 180 degrees out of phase. That's why you get 240V across them.





Electrical Voltages - Electrical 101


Learn more about residential voltages (120 and 240 volts). Includes sine wave, and voltage diagrams, phase relationships, and more.




www.electrical101.com


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## iowagold (Jan 22, 2020)

JayArr said:


> Hi All
> 
> My name is Jeff and I've got a working Homelite EHE4000CSA (UT -03647). I don't find much info on it on the web but it's a standard B&S 8HP motor and the head was configured for 120 and 240VAC. It's 4000W peak, 3600W running so it's 120V-15A times two with a center neutral.
> 
> I need 120V 30A for my travel trailer. I thought it would be a simple task to pull the end cap off and swap the wires around from series to parallel and then wire it up to a travel trailer socket (TT-30R).


snap some pix of the gen set for us.
is this an older flat head gen set?
or a later OHV engine?


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## JayArr (May 3, 2021)

iowagold said:


> snap some pix of the gen set for us.
> is this an older flat head gen set?
> or a later OHV engine?


I believe this is what is referred to as a flat head. Pictures attached.


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## JayArr (May 3, 2021)

More Pics


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## JayArr (May 3, 2021)

Close up of head.


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## JayArr (May 3, 2021)

As you can see, I've modified a few things LOL. It'll be mounted on the tongue of my trailer under a box and run off the same propane system as the trailer. I bought an aftermarket carb and gutted it and plumbed in the propane kit. It also has electric start which was a pretty big factor. I want my wife to be able to start it by herself if I'm not around and I doubt she could pull start a 4K generator. The K&N filter is just for reduced size.


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## iowagold (Jan 22, 2020)

so what is the end game?
a 120 vac gen set?


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## JayArr (May 3, 2021)

Exactly, It came wired for 120/240 with two windings stacked in series with the center of them neutral. Each winding is capable of about 15A at 120VAC. I have no need for 240VAC but I do need 120VAC at 30A. I need to get the two windings in parallel so it meets my needs.

I think my trouble is that I don't know what voltage is supposed to be going to the AVR, is there a standard voltage for this?

Also: I think this was a Canadian model, the CSA at the end of the model tips me off. Has anyone seen a model like this with maybe a slightly different number? I can't find any documentation but if I can find the UAS model number for the same generator I may have have better luck.


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## iowagold (Jan 22, 2020)

the phase windings may not be in the proper stator slots to let you do that.

they need to be clocked for in phase 120 vac.
a good electric motor rewind shop has the test gear for this.

this unit is so old the manuals are not in digital..
hard to say what version of the avr setup they are using.

you will be better off doing a later quiet gen set with OHV
that is unless you are camping alone...

here in the states quiet time in most of the camp grounds you need to be under 50 db
unless you are located in the generator section of the camp ground...
and those camping areas are loud!

what kind of camper?
and i take it you are wanting to run an air con unit?
what brand and model
and same on the microwave.
and how about the battery charger for the house dc?
is it late model or older?


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## JayArr (May 3, 2021)

No AC, just to run for a couple of hours every few days to recharge the batteries. We can live without AC and Microwave when we're camping but if it's spring or fall we can use up the battery at night running the furnace. We managed three days on our batteries last time out so the gen won't even run every day. Our campgrounds allow generators in all sections but only from 8-10 in the morning and 6-8 at night. Basically just to recharge batteries. The rest of the time it doesn't matter how quiet the gen is, it isn't allowed. Running your generator at night will get you evicted.


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## iowagold (Jan 22, 2020)

hummm
why so big on the gen set?
what is the real draw on the camper?
have you checked it?

a smaller gen unit will suck less fuel...


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## Browse Deweb (Jan 16, 2021)

I don't think it would be considerate or appropriate to run a loud generator at any campground or other area where people are spending their time. For this type of application, I would get the quietest and most efficient generator that will meet the requirements. 

Sandwiched between two inconsiderate and loud neighbors and living in a neighborhood with incessant leaf blowing by landscapers, unnecessary noise is a real pet peeve of mine.


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## JayArr (May 3, 2021)

Sigh...

I came to ask questions about how to rewire a generator head and I'm getting judgement on how loud it is and advice to throw it away and spend $1000 on a new Honda.

The way the parks work around here is that it doesn't matter how quiet the generator is, there are no db levels to meet and no incentive to spend a lot of money on a new quieter generator. We all use our generators from 8-10 in the morning or 6-8 at night and then we all shut them off. Even if I spent a pile of money on a brand new inverter generator I still wouldn't be allowed to run it outside of those two charge windows. They are used to charge batteries and if you time your meals right you can run your microwave during the charge time. The rest of the day/night you need to live on battery or from an inverter. It's very peaceful except for these two mealtimes which are always full of activity anyway. There are NO generators running through the day or night, none. If they catch you running even the quietest inverter generator after 8PM you get evicted.

Yes, this old guy is loud but I've bought new rubber mounts and it will live inside a plywood box to muffle it.

As for requirements, my Xantrex pulls 22Amps if it has to charge the battery at full capacity (100ADC). Once it's out of bulk charge and into the maintenance portion of the charge cycle that is considerably less and I could then also microwave some dinner.

The generator is converted to run on propane, it will be plumbed directly into the trailer. that's why you don't see a gas tank in the pictures. I never need to winterize it or worry that my gas has gone bad. It will start every time and there are no longer any moving parts in the carburetor to get gummed up or need rebuilding.

Now back to the original question, can I connect C-lower to A and C-upper to E to get 120VAC at 30A?


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## iowagold (Jan 22, 2020)

a fast ans might be no.
it depends on the phase angle of those windings.

yup i hear you on the cost ...
but the noise on a flat head engine WOW!
lol
i have only seen water mufflers quiet those down a bit....

we do a lot with vendors, and state fair here in the summer time...
a quiet gen is a must for sanity.
our systems end up so quiet they can run during quiet time!!
quiet box, quiet exhaust stack shooting exhaust up with baffles.
that is below 50 db!

I would have invested my time with at least an modern ohv engine...
and wow on your current demand!
think smaller battery charger just for the gen set run, and trip out the 100 amp dc power supply / battery charger when charging batteries when doing the boondocks with out shore power.

question for you how many batteries are you running?
and what exact group size? are they deep cycle? and what brand?

we run in to the same issue on the air stream trailers...
so to conserve power we use led lights,
and have upgraded most of the appliances to modern tri fuel.
except the panasonic inverter microwave.
and it will run on lower settings with the smaller honda eu2200i gen set.

and we use the micro air soft start on the air con unit.
works perfect!


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## iowagold (Jan 22, 2020)

hey a thought you could use a 220 vac to 120 vac step down transformer!
that would work!


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## JayArr (May 3, 2021)

Try to think about how big and heavy a 4000W step down transformer would be, not to mention how expensive it would be. I've got a 1500W transformer in my shop that I have to brace myself to lift, I think a 4000W would weigh more than the genny. LOL

I already own the inverter/charger, it puts out 2500W of AC if needed so we could run the microwave for short bursts if we need to but in practice we never do. It will work great if I can get the generator to output 30A. I'd much rather charge my batteries in one 2 hour block every three days than have generator droning on for hours and hours. To each his own I guess. 

If I can just get these wires figured out I'm operational without spending any more $$ so that's my objective. A new smaller generator would require a smaller inverter generator and that's just a lot of $$ ($1000?, $1500?) that I don't want to spend to be a few db quieter. There is just no advantage to it where we camp.

Jeff


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## iowagold (Jan 22, 2020)

check out this thread
Predator 3200/4000 switch to parallel
also check your pm's


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## Browse Deweb (Jan 16, 2021)

If your 120V receptacle is working, can't you just break the hot connection between the two 120V plugs and replace one of the hots with the other "out of phase" hot wire that is feeding the 240V 6-20 outlet? That should give you two separate 15A 120V circuits.


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## JayArr (May 3, 2021)

That is how it is now Browse,

I have Qty-2 120V 15A circuits that can also be accessed as Qty-1 240VAC 15A. 

What I need is Qty-1 120V 30A circuit.


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## Browse Deweb (Jan 16, 2021)

JayArr said:


> That is how it is now Browse,
> 
> I have Qty-2 120V 15A circuits that can also be accessed as Qty-1 240VAC 15A.
> 
> What I need is Qty-1 120V 30A circuit.


OK...so you need to parallel the two outputs for 30A (sort of like the bottom diagram on my generator):



https://shedheads.net/wp-content/uploads/2017/01/Power-Circuits.jpg



Not sure you can easily do this since they are out of phase. See this thread:








Parallel Windings


Technical question here. Just picked up a Homelite EH4000HDC. 3600 running watts. The unit has a 240v plug, and two standard 120v plugs. Two hot windings, each feeding one of the 120v plugs (for 15A each) and each feeding one side of the 240V plug (for a total of 15A). Would it be possible, to...




www.powerequipmentforum.com


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## JayArr (May 3, 2021)

Hi Browse

Yes, like the lower picture. I've read that thread you referenced and I even started a conversation with cpotter to see if he was successful but alas, he does not answer.

I understand swapping the windings from series to parallel but the extra connections that go to the AVR are confusing me. I labelled them B and D in the diagram and picture.

Is it possible that the voltage detect for this generator is low?


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## JayArr (May 3, 2021)

So I did a little digging and I've found that my generator portion was made by SawaFuji, they apparently made a lot of generator heads for Homelite, Kubota Wacker Neuson and even Honda. I'll try to find a service manual for one of those since I can't find one for the Homelite.

I also did an experiment with the AVR. I fed it 12V into the yellow wires and hooked a light bulb across the field wires that go to the brushes. The light bulb lights but as I raised the voltage on the sense wires (blue and brown) the light goes out at 18VAC. That's quite low and explains why my gen has the extra windings. A lot of AVRs sense directly off the 120VAC output but that means they are using high value resistors to divide down the sense voltage to a manageable level and high value resistors are more prone to drifting and going open. I suspect that the extra winding was so that the AVR could be built for low voltage sensing and therefore be more stable and have less failures.


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## JayArr (May 3, 2021)

I've pulled the wiring apart to separate the lower two windings then I inverted each and joined them in parallel with the uppers. See picture. This will double my current and make it a 120VAC only generator. 

Here's a question I have. B and C are connected and fed to the AVR, Their corresponding point on the second winding is H and E. Do I tie all four together (BCHE) or leave them separate?

The problem with this configuration is that the voltage to the AVR is now half of what it used to be so I'll either have to modify the existing AVR or build a new one that cuts off the field current at 9VAC (instead of 18). It shouldn't bee too difficult, I build regulators for alternators all the time, I'll make it adjustable while I'm in there. The hardest part will be digging the potting/epoxy out of the box to get to the board.


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## Browse Deweb (Jan 16, 2021)

JayArr said:


> I've pulled the wiring apart to separate the lower two windings then I inverted each and joined them in parallel with the uppers. See picture. This will double my current and make it a 120VAC only generator.
> 
> Here's a question I have. B and C are connected and fed to the AVR, Their corresponding point on the second winding is H and E. Do I tie all four together (BCHE) or leave them separate?
> 
> ...


Seems like you have your work cut out for you. If it does end up working, just make sure your new internal wiring can handle the increased current.


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## tabora (Sep 6, 2018)

JayArr said:


> What I need is Qty-1 120V 30A circuit.


As I mentioned WAAAAY back in post #2, this is kinda a snipe hunt... If you need 30A of in-phase 120V from a single outlet, this is not the generator for you...


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## JayArr (May 3, 2021)

I don't know why you think this Tabora, I've found that this same 3800-US (160982) SawaFuji generator head is used on Honda, Kubota and WackerNeuson generators to do exactly that - 120V at 30A. It's rated for that and when configured correctly has no trouble producing it.


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## iowagold (Jan 22, 2020)

hey jayarr do you have a wacker model number?
or an exact honda number?
I have older prints for both of those brands


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## JayArr (May 3, 2021)

I've looked at so many my memory is a little fuzzy but I think the Wacker Neuson was either GP3800A or GV3800A.

I've found all of these manuals online.

BTW, I found engineering reference regarding tying my tap points together and the answer is no, you leave them separate. I found several other generators where the voltage detect was from one leg only. So I'm leaving B/C and H/E separate.


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## tabora (Sep 6, 2018)

JayArr said:


> 120V at 30A


It does give 30A of 120V (on two outlets) or 15A of 240V. But you have to invert one of the legs in order to get it in parallel on a single 120V outlet. You can buy that capacity very reasonably in a used genset without the shenanigans of phase inversion.


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## JayArr (May 3, 2021)

Yes but you know that to invert that second phase all you need to do is swap the right pair of wires right? All I wanted was help figuring out which wires to swap. Instead you tell me to buy a different generator. Did you really think I would read your post, go throw this one in the trash and head out and buy a different one? I just don't understand what you thought that post would actually solve.

I already own this generator - I worked hard, earned some money and purchased it - solutions that begin with "you should buy this different model" aren't very useful to me, I don't have enough money to abandon this generator and buy a different one.

I came here for help not judgement, maybe I shouldn't have.


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## tabora (Sep 6, 2018)

JayArr said:


> Yes but you know that to invert that second phase all you need to do is swap the right pair of wires right?


Best of luck to you. A lot of people have asked how to do this, but I don't believe anyone ever succeeded. Some let out the secret smoke. If you do succeed, I hope you post the solution for posterity!


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## Gen10K (Jun 25, 2020)

To me seems that is better to find a modern replacement, quiter, compact, reliable and more efficient. Some to look on different options.


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