Harbor Freight Generator head 10kw

[Jim_in_Omaha]

Wondering if anybody has had experience with the Harbor Freight 10kw generator head. Its actually more like a 7.2kw with 10kw peak. I'm building a generator and gathering information. Need more startup power than the Coleman 5000 has. I would like to get a ST gen head thats talked about at utterpower.com. They are all over Ebay but the shipping is a kicker for those monsters on top of the price. Theres a HF store locally here.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45416

thx
Jim

 

[KubotaTrax]

Are you hooking it up to your PTO?
I think they are 2-pole windings and that means you'll have to have a 6.6 - 1 ratio on the PTO for the 3600 rpm needed for 60Hz out. Do some checking and see what required for the drive unit. A 20 gas engine's not cheap.
Maybe this will help, or just make it worse.
Ill help anyway possible.

 

[Slamfire]

I'm not very impressed with the Chinese version of bearings or electric wiring, you have as much chance of getting a bad one as you have of getting a good on. When you start purchasin' tools in pairs the low price disappears pretty quick. /forums/images/graemlins/tongue.gif

 

[1962]

jim
i think the ST heads are 4-pole 1800 rpm heads. i already had a 2-pole 3600 rpm winco generator head when i built my diesel powered generator last month. its posted in this forum. but the few people i talked to that had the ST heads were very happy with them. they got them on ebay,i think from ohio. i wish mine was 4-pole, the slower the prime mover runs the longer it lasts.

 

[Soundguy]

Are you buying this to swap into your coleman.. or as a side project.

Speaking o fthe 6.6 ratio gear boxes.. I've not seen a line on these. Obviously someone has them, as all the norhtern hyds pto gennies have one... Would be nice to find a source, as gen heads by them selves are cheap. Seems like you could get a gen head for a couple hundred, and a gear box for the same.. and be at half price on a pto gen.

Any comment on this?

 

[Jim_in_Omaha]

I will be hooking it up to an engine. I'm getting a 4 cylinder military surplus engine 32cid.

It will be replacing the Coleman 5000. So if it works the Coleman will be for sale. /forums/images/graemlins/grin.gif

Its for emergency backup mainly. Not for long run stuff. I need more kick than the Coleman has for running the fridge and furnace startups.

I would expect that the ST heads like on Ebay are great. utterpower.com has alot of info on them. But they are really really big and heavy. And the cost of shipping on top of the purchase price drives the total cost of the project up more than I like.
Jim

 

[1962]

jim, i just tested this gen set out a few weeks back. had to upgrade the spider insert for the lovejoy coupling to a hytel type. holds up 2x under higher torque loads than the buna rubber type.
is your four cylinder engine a wisconsin? i think all the parts for the 32 cid mil. type engines are interchangable between all the manufacturers.(onan,wisconsin,ect).

 

[SPIKER]

I too have taken a good look at them @ HF. seems like a good place to start when a backup is needed... I'm not sure what the# of Poles were, I don't have TRUE plans on building one just yet. usually you can find them in the paper or auctions around here for a few more $s than the parts alone would cost but the untis need a good inspection 1st...


I was also looking at the SOLAR systems that can store XX power in batteries which seems to also be a great way to go if you can have a place for a few good sized batteries & a big enough Inverter to convert to VAC form the DC...


HF has those on sale now in the 500 watt range /forums/images/graemlins/smile.gif
Makrm

 

[Jim_in_Omaha]

I went back and read your posts on yours. I like the diesel.

I have not received the engine yet. The last 4A032 I saw was a Teledyne/Hercules. But I know they have been made for a long time by multiple companies.

The HF gen head is a 2 pole 3600 rpm. I question its reliability. I suppose when I get ready to get the gen head I could buy it and test the crud out of it for a couple of days. And if it dies take it back since the store is here in town. Its $299.

Jim

 

[1962]

jim,
those were and still are great engines. we used them alot in the military to power our electric needs in the field. they always seemed to be way more powerful than the engine tag read. my gen heads a 2 pole. and for back-up power it should last a long time. i think the 4-pole heads are better suited for 24/7 running. i built a 2 cylinder wisconsin powered generator 5 years ago and only put 46 hours on it as back-up power in the 5 years.
like you stated, the shipping cost is high for those heavy cast iron 4 pole heads. i got this used USA made winco 8kw head for $200.00, and took it to a electric motor rebuild shop for new timkin bearings and a complete check-over. i only went with a diesel because i can store the treated diesel fuel longer and i have it in a 60 gallon storage tank.
i asked the tech's at the electric motor shop about the comparision between a 4 pole with brushes and a 2 pole brushless gen head. they told me unless you were powering a small community 24/7, the 2 pole brushless will last a long, long time for back-up power needs. that was good enough for me. /forums/images/graemlins/smile.gif

 

[v8dave]

4-pole generator heads will spin at 1800 rpm to get 60 Hz AC power. A 2-pole generator head will spin at 3600 rpm for 60 Hz AC power. It's easier on engines to run them at 1,800 rpm which is why the 4-pole generators runing at 1800 rpm are more likely to be found in 24/7 application.

Not to say that 3,600 rpm generators won't last a while when running 3,600 rpm. Kubota offers several Diesel gensets that run at 3,600 rpm and they are touted as being able to run 24/7 service. Although, I doubt they would hold up for a year's service that way. For stand-by, worksite and occasional use they work just fine.

I don't remember who first posted this formula from here on TBN. But, the formula is: NP = (F * 120)/RPM
or
Number of Poles = Frequency times 120 and divided by RPM

A thing to look for in building a belt powered genset is to be sure your generator head is a two bearing unit. Single bearing generators are intended to be mounted on the engine's bell housing/flywheel and use the engine rear main bearing to support the front (input) shaft of the generator. Two bearing generators are built to handle the side load a pulley drive will present.

 

[Jim_in_Omaha]

Something I'm wondering is,
If a person buys a 7kw head and runs continuous 5kw load, would it require approximately the same HP to run that same 5kw load on a large 12kw head? According to all the things I'm reading it would be about the same give and take for drive coupling and how efficent the head is.

The reason is because if I was to go with a ST head like off of Ebay I would probably go with a larger KW head just in case higher capacity is needed someday.
jim

 

[1962]

sure, you can do that. you can have a 20kw head, and it's only going to put out what you put in. the prime mover engine rating rule is 2 horsepower per every 1000 watts electric output. that is taking into factor altitude, heat, and other losses. so you could put a 12 hp engine on a 15 kw head and you will get 6 kw of useable power out of that set-up.

 

[Highbeam]

Plus, the larger than needed generator head will have bigger parts that weigh more to offer more of a flywheel effect for starting up higher loads. The parts are built and sized to handle the high amperage so they should hold up better than a 100% utilized smaller head.

 

[XmasTreeGrower]

Jim
Just to answer your original question; I purchased the same unit you are looking at from HF, and used it for 96 hours non stop during one of the hurricanes last year.

It performed flawlessly, handled my whole house, ran the computer and electronics OK, etc.

I personally find the 3600 rpm feature easy to deal with since this is the governed speed of almost all small gas engines. I threw a pulley on the front of the head, and used the PTO belt pulley from my Steiner tractor to power the head. Bolted the head down to a small pallet, staked the pallet down with some rebar, hooked up the belt, and away we go! Takes about five minutes to set up and take down. I am certain anybody could come up with any number of creative use of pulley sizes to get whatever ratio you need. In the case of my power plant, it was a simple one to one ratio. As was noted, a straight Lovejoy coupling off a horizontal shaft engine would be fine as well.

Incidentally, the Steiner has a 18 hp Briggs opposed twin, and it kept up fine at peak loads.

It takes up very little room in my shed, patiently waiting for it's next call to duty. It was definitely one of the best $300 bucks I have ever spent.

Thanks
Bill

 

[Jim_in_Omaha]

Thanks Bill..
Not sure what I'm going to do for the gen head. I got a price for a 12k Mecc Alta Italian made unit $525. It looks like the Northstar unit from Northern without the fancy output box. Just a junction box.

One thing I found was the display unit at the Harbor Freight store (which has been there awhile) said that the continous is 9.2kw with a 10kw peak. It looks just like the current #45416 with the same number. I wonder if they de-rated it at some point for the continous rating.

Did get the engine. Military standard 4A032-4 by Teledyne. Ran if for about 30 minutes. Held it down with 1 C clamp. Very little vibration.
thx
JIm

 

[Highbeam]

We must have pics.

 

[Jim_in_Omaha]

So far this is all I got. An engine. Its like a mini volkswagon flat four air cooled.
thx
Jim

 

[Highbeam]

That's great.

 

[TOMLESCOEQUIP]

Jim........Let me know how the engine works out for you...........I have the same engine, govt. rebuilt with 6 (test) hours on it. I got mine at a city auction about 10 years ago, test ran it & its been waiting for an application ever since.