Harbor Freight Generator head 10kw

[Soundguy]

</font><font color="blue" class="small">( BUT the one thing he forgot is when you are generating you're OWN power it is limited by the power plant I.E. )</font>

Good point. I was using a 'fixed' 220 vac provided by a 'utility' line.. more or less an 'unlimit3d' supply. As we all know.. when you overload a genny head, voltage output drops off... that rearanges the ohms law calcs.. .. usually right before the breaker pops! /forums/images/graemlins/grin.gif

Soundguy

 

[1962]

i considered using a gear box on my home made gen set. the only reason i didn't use it was i didn't feel like pressing the bearings out and replacing them with new ones. i don't remember the ratio, but it has two bull gears in a gear oil bath. maybe in a few years i will change it. as for the love joy lo-195 coupling, i had to upgrade to a hytel type spider insert. it seems like the heat generated from the engine and the gen head got the buna-n spider too hot and it started to fail, and quite possibly the torque load was too much for it.
the shaft alignment is right on, and after a 2 hour test today everything seems ok for now.

 

[Jim_in_Omaha]

I was thinking about your coupler and remembered reading about what the guy at utterpower.com had to say regarding couplers.
http://www.utterpower.com/coupler_.htm

I was wondering if maybe your diesel's high torque pulses were contributing to the destruction of the lovejoy insert after reading that.

Also on his site he talks alot about pulleys. For the bushed pulleys grainger.com has a good selection. Surpluscenter.com has great prices on standard pulleys.

thx
Jim

 

[Jim_in_Omaha]

Heres a response back from the tech support at Harbor Freight regarding this generator. Notice the revisions/errors which explain why the one at the store I saw had a continuous rating of over 9kw.

The one point that I'm wondering about here is they say its 50% efficiency via belt drive and 85% efficiency via gear box (perhaps direct coupling too?). Thats seems like a large difference. Any comments from the engineering experts here at TBN as to just what that means in real world terms would be appreciated.
thx
Jim

----------------------------------------------------
DIMENSIONS 19-3/8"L X 7-3/4"W X 8"H.
WEIGHT 85.6 LBS
THD 3-4%
COPPER WINDINGS
RATED @ 7200 WATTS CONTINUOUS
16 HP ENGINE IS RECOMMENDED. THE ENGINE SHOULD PRODUCE CLOSE TO 20
FT/LBS.
OR MORE AT 3600 RPM. NOTE THAT MOST ENGINES WILL PRODUCE PEAK TORQUE
AT A
LOWER RPM. CAN BE MOUNTED TO A FRAME OR SOLID PLATFORM WITH METAL
BRACKETS.
OR STEEL STRAPS.
TWIST LOCK RECEPTABLE IS RATED 30 AMPS.
13-1/4" X 6-1/4" ON CENTERS
120V: 20 AMPS
240V: 30 AMPS*** CAT/WEB ERROR ADVERTISED AS OK WITH PTO 11/02 ***
IS DESIGNED TO RUN CW (AS YOU FACE THE SHAFT), BUT IT WILL WORK IN
EITHER DIRECTION.
(1) 300-VOLT METER
(1) 150-VOLT METER
THE EFFICIENCY RATING OF THE GENERATOR HEAD: APPROX 50%, WHEN
BELT-DRIVEN WITH
A 20 HP ENGINE. THE EFFICIENCY INCREASES TO ABOUT 85% WHEN GEAR-DRIVEN.
CAPACITOR: 45 MICROFARADS, 450 VAC. THE SHELL IS 4-3/4" LONG X 1-3/4"
DIAMETER
MAX. AMBIENT TEMPERATURE IS 45 DEG C, (113 DEG F)


COMMENTS: CAT/WEB ERROR ADVERTISED AS 1725 RPM 06/02
CAT/WEB ERROR ADVERTISED AS 9500 WATTS CONTINUOUS 07/02
CAT/WEB ERROR ADVERTISED AS REQUIRING A 20 HP ENGINE 08/02

 

[Highbeam]

As far as the efficiency goes, a HP is 745 watts. 16 HP gets you 11931 watts and at 50% efficiency you can only get 6000 watts out of the setup. At 85% you get the full 10,000 watts which oddly lines up with the 10kw model name.

The efficiency will not be 100% but a direct coupling will be more efficient than a gear box.

My best guess is that the efficiency rating is the total loss between the crankshaft of the engine and the available amperage.

The efficiency of converting btus of gasoline into amperage will be way worse but that is not the fault of the generator head.

 

[1962]

well i trashed the hytel spider, after 3 hours of running. i think the torque and the heat from the gen head is too much for it. the last generator i made was a 2 "B" belt set up and it worked great. so now i have to decide wheather to go with a universal type coupling or a stronger chain type coupler. or maybe just start over with a new frame and go with the trusty belts. this engine puts out 31nm @ 2400 rpm's. i dont know how to convert the metric system to foot LBS of torque. but if i do go with the belt set up, i like having the engine run at the slower rpm's than the 3600 direct drive speed.

 

[gbirky]

31nm = 22.9 ft-lb. At 2400 rpm, 31 nm makes about 14hp

22.9*2400/5252 = 14.2 hp

 

[Highbeam]

How about a bigger lovejoy? They make some big ones.

 

[1962]

thanks for the metric conversion greg. yes, they do make some big ones. tomorrow morning i will pick up a #40 chain type coupling from grainger. the bigger lovejoy is a bit more $$ than the chain type, and heat might still be a factor with the plastic type spider. the chain coupling is all steel and should be better for the higher temperatures. if that fails, /forums/images/graemlins/confused.gif it's back to the drawing board and a belt drive.

 

[SPIKER]

as far as the eficiency goes the belt SLIP will lkoose the extra amount. No way around that. the GB is less efficient due to losses in the gear box. the dirrect drive is most efficient.

msark M