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I'm about to pick up a 8KW Generac stand-by generator - have questions.

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bczoom

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My Dad is upgrading is perfectly working and maintained 8KW Generac to a 14KW so he has whole house power.
I'm going to take his old one (they wouldn't give him anything for it) including the transfer switch.

I have questions & looking for thoughts.
1) It's currently NG and I'd switch to propane. This may be Generac specific (by model?) but I read the fuel transfer equipment is built in. Just throw a knob. Anyone know about this?
2) I may want to run it manually, as if it was a portable generator. No use in running it constantly if all I want to do is keep the reefers cold and run the microwave. How would I do that electrically?
3) Looking for fuel burn amounts. If I go full-blown, I'd bring in a 500 gallon propane tank but wondering how long a 100-pound propane tank (22 gallons) would last.

Other thoughts/advise? I'm sure I'm going to want/need more info.
 
If you have the manual for it, I would look for the info in it on running specs. If you dont have the manual, I would search online for getting one. That is the best info I can give you without knowing more about it such as engine size, fuel burn with load ranges, etc.
 
I dont have any specific facts either.
However
I do run a ng 30kva generator.

I have run it on lp. It was touchy to start on lp but once it lit up it seemed very happy. My research by trial and error led to two observations.
One was it was not able to over come the lp gas pressure as my regulator was to high of wc. (Water column) for the ng apparatus.
My generators output is 208v Y configured. Im not sure my well pump likes it.
 
We have Briggs back up 22K generator at out fire house on propane actually it has better out put on propane more BTU per pound
when we switched propane suppliers I just hooked it to 2 100 lb tanks and it ran for 2 weeks exercises at about an hour a week we have 200 A service AC was on. when I switched back to the 1000 gallon tank the 100's felt like I hadn't used them at all. wit 2 hours run time on them.
 
bczoom said:
My Dad is upgrading is perfectly working and maintained 8KW Generac to a 14KW so he has whole house power.
I'm going to take his old one (they wouldn't give him anything for it) including the transfer switch.

I have questions & looking for thoughts.
1) It's currently NG and I'd switch to propane. This may be Generac specific (by model?) but I read the fuel transfer equipment is built in. Just throw a knob. Anyone know about this?
2) I may want to run it manually, as if it was a portable generator. No use in running it constantly if all I want to do is keep the reefers cold and run the microwave. How would I do that electrically?
3) Looking for fuel burn amounts. If I go full-blown, I'd bring in a 500 gallon propane tank but wondering how long a 100-pound propane tank (22 gallons) would last.

Other thoughts/advise? I'm sure I'm going to want/need more info.
Click to expand...
Just off the top of my head and doing research over the years, I teach it on a larger scale 😉 . The generator should use a battery for starts so it can be run in auto (in auto it would have to see a load etal transfer switch) or manually started. If you wanna make it “portable”, put it on a skid with a breaker box and outlets. The generator looks at synchro speed and typically small engines maintain 3600 rpm and larger 1800 rpm (60 cycles). The more load that is applied the generator will induce excitation voltage causing the rpm’s to want to drop BUT the generator will sense the loss of rpm and introduce fuel to maintain speed.
 
A Generac 8kW home standby generator typically uses either liquid propane (LP) or natural gas. At half load, a 8kW model consumes roughly 0.87 gallons per hour of LP or 72 cubic feet per hour of natural gas, according to Norwall PowerSystems. Fuel consumption varies with load, so at full load, it will consume more fuel.
 
I have a much bigger generator, Kohler 50kw with GM 305 running on NG. My home/garage normal load is 7-9kw, less than 25% load. Its NG use at 25% is approx 300 cu/ft per hour. We just had a 30 hour outage and I went through near 10,000 cu/ft. Thank goodness I get free gas!
 
Big Dog said:
A Generac 8kW home standby generator typically uses either liquid propane (LP) or natural gas. At half load, a 8kW model consumes roughly 0.87 gallons per hour of LP
Click to expand...
Gulp. That's a 100 pound tank per 24 hours. That's $75 in propane for each day. That may be the deciding factor on using it manual vs auto. If I run it 2 hours/day to keep the freezers going and the water hot, I can get almost 2 weeks for each 100# tank.
 
There's a lot of energy used just to keep a 305 spinning.
There should be specs listed on the net for your particular machine. If not. Call the OEM. They'll know
 
Big Dog said:
I have a much bigger generator, Kohler 50kw with GM 305 running on NG.
Click to expand...
I have a 30KW Onan genset running off a beautiful 300CID Ford industrial engine.
The genset is no good (previous owner mis-wired) but the engine is flawless.
It's for sale if anyone needs it.
 
bczoom said:
I have a 30KW Onan genset running off a beautiful 300CID Ford industrial engine.
The genset is no good (previous owner mis-wired) but the engine is flawless.
It's for sale if anyone needs it.
Click to expand...
it can be rewound if you wanted to spend the money. the shop I use for motors does them regularly
 
tommu56 said:
it can be rewound if you wanted to spend the money. the shop I use for motors does them regularly
Click to expand...
I think I looked into that awhile back but it was really expensive. I thought it too expensive for a 50+ year old generator.
Just hoping to find someone that can use the Ford engine.
 
waybomb said:
There's a lot of energy used just to keep a 305 spinning.
There should be specs listed on the net for your particular machine. If not. Call the OEM. They'll know
Click to expand...
Everything I share the last couple days came from internet seraches. In my generator case, from my manual.
 

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bczoom said:
I thought it too expensive for a 50+ year old generator.
Click to expand...
A quality 50-year-old gen set is probably way better built than the Generac junk you can buy new today.
Copper was cheap back them. Build quality was also better.
Get an estimate for repairs then decide.
 
I already have 7 or 8 generators, not counting that 50-year-old one.
This Generac is free so I couldn't pass on it.
I thought I recall having that old generator repaired was something like $1500-2000. More than I want to spend on it.
 
After literally years of research on SB generators, I became convinced on an 1800 rpm machine which typically means a 4+cylinder. I just wasn’t going to risk a 2/3 cylinder Briggs running at 3600rpm loaded, the torque changes in sudden load changes are their detriment.
Generacs do very good in the smaller engine class but yeah the weak spot can be the generators themselves. It is imperative to do a complete annual inspection and PM.
 
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