Harbour freight gen heads

[Doug]

How many of you guys have one of these?

What kind of regulation and reliability ?

Hard choices, ST5 or this both come out about the saem when the dust settles.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45416

Doug

[Ironworks]

I was considering buying one of those.  They had them at a HF store nearby on sale for $179.00.  I thought I'd better wait until someone else tried them out.  Somebody on here bought a couple a while back. I'm still waiting to hear how they work.

[OffGrid]

I’m running a 5kW head from Princess Auto, a Canadian company that looks to carry similar stuff to HF in the U.S.A. This one is made by Voltmaster in Illinois just outside of Chicago. A lot of similarities, you think?

After about 50 hours the bearings started to get noisy. Easy enough to replace. About 10 hours later, the unit would only output about 100 VDC 60 HZ at 3,600 rpm. The company sent me a new cap, diodes & veristers (UPS collect). It now has about 10 hours on it & so far so good.

A reliable choice to run a loved ones heart lung machine, na. 

[cujet]

I have friends who have used the 10KW HF head with good results. I would guess the power produced would be better than the ST.

Here is my take on the ST: it is like a Harley Davidson, simple and rugged once you get the bugs worked out. But to get it to be competitive with a modern machine takes mods, time and money.

Chris

[okiezeke]

I ran a 5KW harbour freight gen head on my boat for 4 years.  Had it belt driven from the harmonic balancer pully on the main engine(30hp diesel).  Never had a hint of trouble with it.  Used it mostly to run AC air conditioning.  Had 12,500 btu system and the gen carried it just fine.  I'd say the're worth the money.
Zeke

[Doug]

Thanks for input guys I'll check Princess Auto online again and see if I can find something.

The HF head right now even with shipping has a price advantage over the ST in Canada even with shipping.

Doug

Looked for what Princes has to offer

http://65.110.80.25/pdfs/02_Farm.pdf

Kind of scant offerings and the price puts it right back up in the ST range....

[OffGrid]

The princess auto has held together for the past few days running 24/7 under load. It was a bad diode. The tech at Voltmaster said above 64 Hz damage may occur. I may have switched off all the load and the Listeroid governor being not very tight, turned the thing a bit fast. 
 
I must say the sine wave looks good on a scope. Doug, you of all people better not ask for a picture

The higher 3,600 rpm speed and noise from the belts, does not match the the nice thump of the engine. A 4 pole would be nice for that plus longer bearing life (after replacement with good ones)
 
One thing about Princess Auto, if your not happy, bring it back for a replacement of refund. They a great that way. But if it dies just when you need it, that's no help either. Cheers

[Doug]

I only ask for pictures from people that promiss to use sharp crayons.......

I'm ready to close a deal, ST head, Princess head and Harbour head are all about equal in prices......

There are deals out there if your polites and honest.

Doug

[snutr]

Just curious, I see from the manual for this gen-head (http://www.harborfreight.com/manuals/45000-45999/45416.pdf)
that it states that a 10HP motor would be required to turn the generator at 3,500 RPM.  So I'm assuming that a 6/1 will not be able to handle this gen head.  Is that a correct assumption?

Also, where is a good place to get a suitable pulley for a gen head or alternator?

[Andre Blanchard]

It is not that it will not turn the generator head, mostly it is just that then your power is limited by the engine, you will only get 3 to 4 Kw out of it.

Upside is the chances of overloading and burning up the head are almost zero.
Downside is you paid for more generator then you can use and you will burn ever so little more fuel for the power you are getting do to greater losses in the head.  I think the biggest one would be wind, the cooling fan will be moving more air then you really need.  All up unless you get extremely oversize on the head it will be difficult for the average user to measure the extra fuel burn.

[TerryM]

If you're looking for an alternative to an ST head, check out the "Blaster Wholesale" website located here:  http://blastwholesa1le.com/products.php?cat=11.

They are offering two models of 2-bearing generators with shafts set up for belt drive - one is 5 KW and the other is 7.2 KW - both 3600 RPM.  Pricing is $350 and $400 respectively.  I think that Blaster is a one-man outfit, but he filled my order promptly and answered the phone when I called to inquire about shipping status. 

These generators are made by Mecc Alte Spa which is an Italian company.   I purchased the 7.2 KW unit which carries a 7800 VA continuous rating on the label plate with a 10% overload allowed for 1or 2 hours out of 24.  I'm driving mine with a Changfa-style 1115 using a H100 synchronous belt.  Whatever noise the generator makes is completely swamped by the racket from the engine. 

So far I've briefly loaded it to 7 KW and put a 4.5 KW load on it for half-an hour or so.  The generator case was never more than slightly warm to the touch - I'd guess 100 degrees F or so.  One noteworthy aspect of this generator is the voltage regulation.  No load to 4.5 KW causes the output voltage to sag only a volt or two.  It's a brushless design, and I think that it somehow uses current drawn from the armature to add to the excitation of the field.  I haven't been able to locate a good description of the theory of operation, but it works very well.

One thing that is important to keep in mind is that a 3600 RPM generator is more difficult to drive than an 1800 RPM unit using a medium speed diesel like a Changfa (I assume that this is even more true with slow speed diesels).   With the dinky little 5" or 6" sheave that comes with a Chanfga-style engine, you need to use a 2 1/2" or 3" sheave to get the 2:1 drive ratio required by the generator.  Those kinds of diameters violate the minimums recommended by sheave manufacturer's like Martin and Maurey, plus you've got to use 4 B sized v-belts with a lot of tension to handle the power.  Most 3600 RPM gen heads aren't built for a lot of side load on the shaft, so bearing life isn't apt to be real good.  Purchasing a larger 4 groove sheave (8" - 10" dia) for the engine shaft along with the bushing can easily run over $200 by the time you include the belts.  I like my Mecc Alte gen head, but the next one I buy will be an 1800 RPM unit.

Terry

[snutr]

It is not that it will not turn the generator head, mostly it is just that then your power is limited by the engine, you will only get 3 to 4 Kw out of it.

OK. So in the end it's just the same thing as running an ST 5KW gen head right?
The reason I 'm hot on this is that Harbor Freight just opened a store near me so, although I'll have to pay sales tax, I don't have to pay shipping.  Also, the harbor freight one is $150 (plus freight) cheaper than the ST 5KW head.

So where do you get pulleys for it and what size pulleys do you get if you're running a 6/1?  Do you run the equation for the 24" flywheel using 650RPM for the engine and 3500 for the generator pulley?

[TerryM]

Snutr, I'm not your best resource when it comes to slow-speed diesels like the lister.  I think you may have some flat belt options with that engine that I'm just not very knowledgeable about. 

If it does turn out that you have to fit the engine with a new sheave, you can find a wide array of v-belt and synchronous sheaves at Applied Industrial.  They carry a variety of brands, but seem to push Martin Sprocket and Gear components pretty hard.  The Martin website has an absolutely excellent set of design guides that will walk you through the process of selecting the right sized sheave and belt that can handle the power you're using.

Terry

[Andre Blanchard]

It is not that it will not turn the generator head, mostly it is just that then your power is limited by the engine, you will only get 3 to 4 Kw out of it.

OK. So in the end it's just the same thing as running an ST 5KW gen head right?

There are differences but it should work fine.

The reason I 'm hot on this is that Harbor Freight just opened a store near me so, although I'll have to pay sales tax, I don't have to pay shipping.  Also, the harbor freight one is $150 (plus freight) cheaper than the ST 5KW head.

So where do you get pulleys for it and what size pulleys do you get if you're running a 6/1?  Do you run the equation for the 24" flywheel using 650RPM for the engine and 3500 for the generator pulley?

Always nice to have the chance to look something over good before handing over money, also makes a no name or address cash transaction possible.  The fewer people who know what I spend my money on the better I like it.

I had an old used $30 4000 watt 3600 rpm head on a 6/1 for a while, the diodes in it were burned out when I got it and after fixing it with some scrap box parts it run hot even with no load, burned it up running a 10000 BTU AC last summer.  Just had one 4L1000 belt running on the flywheel with a 4 5/8 inch (maybe a little bigger 4 7/8) A/B pulley on the head.  I did have to slow the engine down to something like 610 or 620 rpm..

Remember when figuring the ratio V belt pulleys are measured on their OD but you are running the belt on its ID on the flywheel.
When calculating pulley sizes all you need to remember is the speed ratio is equal to the diameter ratio and solve for the unknown variable.  There are calculators all over the net if you need more.

After burning up the 4Kw head I wanted to get a 208V 3ph head, and I needed it soon because it was hot and I had gotten used to the AC.   Smallest I could find was 25Kw, so ordered it and a 3 grove A/B pulley, 8 7/8 I think, engine is still running a bit slow.  With V belts it is more difficult to get an exact speed ratio because the effective diameter changes so much within the width tolerance of the belts.  I have been running that big head for a while now with the same single 4L1000 belt, at first it chirped a bit on the power stroke but after it wore thru the paint on the flywheel it stopped doing that unless it is really loaded down to the point the speed is dropping off.

I do not expect the belt to last long and it is not as nice as a flat micro v but it was $11 at the hardware store on the way home from work.