OMG, what have I gotten into?!?!? GENERATOR HELP!

milkmania · 07-25-2016, 09:36 PM

I need to attach a Generac generator head from one direct drive propane engine, to a heavy steel plate and attach (with pulleys) to a Diesel engine...

This is a 15,000 watt, 120/240volt, 60amp whole house backup generator, that has a control panel that senses when the utility company's electric goes out and kicks on, then kicks off when power is restored... Also, it tells the engine when to start up and excercise.

I will be using the generator head with a control panel that I tell when to kick on and when to kick off with present controls at driver's seat.

Should I just eliminate the Generac's brain and use the cables coming out of head and wire up a transfer box to switch between shore electric and generated electric.
It would be nice to keep the VOLTS, AMPS, and HERTZ gauges. I could probably just build a box and transfer the electronics to the new box & cover, and mount it inside the bus.

Dayum there's a lot of wires!!!!

What would YOU do? I've got $0 invested in the Generac

Hank's P-O-S · 07-25-2016, 10:07 PM

I would like to go into more detail however I am on mobile.

I have done this several times, some have worked well and others not.

If it is just a generator head with no fancy controls for the head itself, remove all generac "brain boxes" which I have found to be a pita.

All you need to effectively use a generator head is volts, with one meter for each generator leg to ensure the load is at least a little balenced, amps (again for each leg) and hertz.

If you don't mind doing a manual change over, I would suggest using a manual transfer swich. Which have less to fail than an automatic.

Generally the generator and engine will be connected with a morse taper. What is usually the easiest way to atach a stub shaft to the generator head is to cut the engine side of the shaft off at the crank counter balance.
If the shaft is a size you can find hardwear for simply cut a key way into the shaft with a grinder, if not have someone machine the shaft to the size of your choice.

I will put a Better write up together tomorrow, however until then I would suggest digging through the archives of utterpower.com
http://www.utterpower.com/a-free-diyer-generator-head/
The have covered projects like this many times.

milkmania · 07-25-2016, 10:23 PM

Quote:

Originally Posted by Hank's P-O-S

I would like to go into more detail however I am on mobile.

I have done this several times, some have worked well and others not.

If it is just a generator head with no fancy controls for the head itself, remove all generac "brain boxes" which I have found to be a pita.

All you need to effectively use a generator head is volts, with one meter for each generator leg to ensure the load is at least a little balenced, amps (again for each leg) and hertz.

If you don't mind doing a manual change over, I would suggest using a manual transfer swich. Which have less to fail than an automatic.

Generally the generator and engine will be connected with a morse taper. What is usually the easiest way to atach a stub shaft to the generator head is to cut the engine side of the shaft off at the crank counter balance.
If the shaft is a size you can find hardwear for simply cut a key way into the shaft with a grinder, if not have someone machine the shaft to the size of your choice.

I will put a Better write up together tomorrow, however until then I would suggest digging through the archives of utterpower.com
A Free DIYer Generator Head? | UtterPower.com
The have covered projects like this many times.

AWESOME! I look forward to hearing back from you.
And I want to get away from anything automatic! Yes, I found utter power pulleys a couple days ago, but I don't have generator head and propane engine separated yet, so I didn't have any shaft sizes.

The reason I need to power via pulleys is because the generator head needs to run beside the diesel motor because the new head will make the entire unit too long for its opening without major modification. As it is, I can remove the condenser & 7 fans that are behind the Diesel engine(toward the inside center of bus.

Plus, it will also be rotating an alternator via pulleys.

milkmania · 07-25-2016, 10:37 PM

Generac has discontinued this generator (Fiat propane engine), but they were nice enough to email me the repair manual... 78pages

milkmania · 07-26-2016, 08:39 PM

Got the gen head pulled... That's sum biatch is HEAVY!!!

There's 4 bigger wires coming off of it, and several smaller wires (I'll get pictures tomorrow)
I figure two wires are 110v windings and two are 220v windings. Two of those wires went to a 60amp double pole breaker. (Never saw wires bolt onto a breaker before)
EDIT: 80amp, not 60amp
A red and a black wire go in behind the back bearing housing. I'll pull that cover later and see what they operate... Perhaps rpm or heat sensor, no idea yet.

There was a separate plate that bolted to the engine, then the gen head bolted to that. So, that'll be easy to establish my bolt pattern when I cut and weld a mounting plate to go beside the Mitsubishi engine on bus. Plus there's mounting feet and rubber vibration bushings on the opposite end. I'll also be able to pull the geared flywheel that the starter engaged to start the engine.

It's going to mount pretty solidly! Just have to make slots to move gen head over to tighten the belt drive pulleys. Or weld large nuts to plate and use bolts to push or pull the gen head over to tension the belt.

Anxious to pull the flywheel and see what kind of armature end I'm working with!

I need the 220v side for a single stacked apartment sized washer/dryer set. If I'm hooked to RV site electric, just disconnect, start generator, dry clothes, disconnect generator, and reconnect RV site electric. (During day time hours)

milkmania · 07-29-2016, 06:48 PM

Well....
I pulled the generator head, and learned it does have a tapered shaft

Does anyone know if they make a tapered pillow block?
This style of bearing would allow me to carry the front shaft, while the generator housing has the bearing for the back of shaft.

I didn't realize the front of shaft was carried by the propane engine's main bearings

If I can carry the front bearing... Then I can add a pulley to front of generator and build a plate to hold the generator, and use pulleys between the Mitsubishi Diesel engine and gen head.

I have a plate that went between the Generac engine and gen head... So, I'll use it to establish my bolt pattern for the vertical plate that will hold up the front of generator, and there's 2 foot perches on the back of gen head to mount to back of plate with rubber mount bushings.

ol trunt · 07-30-2016, 01:27 PM

How about this? Cut the female end off the propane motor's crankshaft and slip the cut end back over the head set input shaft, turn it down to fit your drive pulley, add a slot for a key way and there you go. Or, weld the cut off female part directly to your new drive pulley, slip it on the head set shaft and secure with a dowel/set screw etc. etc. How's that for back seat driving? Jack

milkmania · 07-30-2016, 01:57 PM

Quote:

Originally Posted by ol trunt

How about this? Cut the female end off the propane motor's crankshaft and slip the cut end back over the head set input shaft, turn it down to fit your drive pulley, add a slot for a key way and there you go. Or, weld the cut off female part directly to your new drive pulley, slip it on the head set shaft and secure with a dowel/set screw etc. etc. How's that for back seat driving? Jack

Thanks, great idea!!!
I'll address that in a moment... I just had a revelation!
I don't NEED that bell housing... I can remove it, copy the rear plate out of plate steel, add the pillow block to carry the front end... Then I can have front mounting feet!

The bell housing is 3" deep.

milkmania · 07-30-2016, 02:09 PM

Back to turning down front female... It's actually a cast steel flywheel

milkmania · 07-30-2016, 07:43 PM

Something else I'd like to address....

My rear Mitsubishi motor has a grill, open on the side, but there is a fan, shroud, and radiator toward the back of the unit facing rearward.

Incredibly loud!!!! BAD LOUD!
And when I put a horse stall mat behind the grill (below), it quietens down by a lot!

Since the side is open... I hear the engine, internals and fan noise right there beside bus.

Radiator from under back bumper

What would the negative points be for installing that horse stall pad permanently with screws of course.

I ran it with pad in place for an hour and it didn't overheat. Probably because it's pulling air through the radiator.

BusFiend · 07-30-2016, 07:46 PM

Quote:

Originally Posted by milkmania

What would the negative points be for installing that horse stall pad permanently with screws of course.

You'll have to stand in muck in the stall?

milkmania · 07-30-2016, 07:51 PM

Quote:

Originally Posted by BusFiend

You'll have to stand in muck in the stall?

I carry a big shovel

milkmania · 07-30-2016, 09:00 PM

Found a pulley calculator.... Pulley Calculator. RPM, Belt Length, Speed, Animated Diagrams
The Generac documents says it runs the propane engine at 1800 rpm, and it's direct drive to gen head.

I'll be connecting Mitsubishi Diesel engine to gen head via pulleys.
I'd like to stay around idle speed on Diesel engine, so I'm guessing 1000rpm.

If I use a 10" pulley on diesel engine, and a 5" pulley on gen head and 14" between centers... I'll be at 1:2 ratio
So, the 1000 rpm diesel engine compounds to 2000rpm on gen head and 900 rpm on diesel engine will compound to 1800rpm on gen head.

1) Am I wrapping my head around this correctly?
2) Can I slow the diesel engine down to 900rpm?
3) How would I add a tachometer to diesel engine, so I can adjust rpm?
4) Or do I need to reverse pulley sizes and adjust rpm from there?

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