Generac 48kw generator: DOA, Generac unable to repair/not helpful

[workinonit]

What size service do you have?

 

[grsthegreat]

Wow 24kw? I can run two window ACs, one hot tub pump and hot top filtering, one stove burner and well pump and some other lights and appliances and max I used was 9KW. If I used the washer and dryer ad 1.6kw to that.

For me to get to 24kw, I would have to simultaneously run washer and dryer, two elements on stove, 3 window AC, Hot tub with two jets running, heater heating and filtering, Air Compresser, well pump, heat and hot water, with 4 circulater pumps and well thats still 16kw...

its not just what you can run, its how maxed out you want to run generator at. during my last 14 hour outage, my gen maxed out at 5.8kw. its a 22kw generator, but since it was summer time i didnt have all the heated horse waterers, heated greenhouse (wife insists), and misc winter loads on it. good thing was it only ran at about 25% load, and only burned a little over 1.2 GPH. (19.66 gal in 14-1/2 hours). now, normally i wouldnt even run it during daylight hours (when the power went out) but wife had her quilting group in basement working away. had to keep her happy.

now if i only had a 11kw unit i would have used more fuel per hour of use, and would not be able to handle my winter loads, which include hot tub heater.

now as far as oil leaking in air cooled units. there was an issue years ago, before the redesign. i dont have many issues with it anymore unless owner overfills unit. one stupid thing generac has is a 1.7 qt oil fill with new filter. lots of nutters out there overfill with 2 full quarts. best case is overflow thru crankcase breather tube. worst case is blown oil seal. those oil seals SUCK to replace....hours of work. if you fill it properly i cant remember a single leak in the 100's of units i take care of, until i go older than 2008 series.

 

[ponytug]

Wow 24kw? I can run two window ACs, one hot tub pump and hot top filtering, one stove burner and well pump and some other lights and appliances and max I used was 9KW. If I used the washer and dryer ad 1.6kw to that.

For me to get to 24kw, I would have to simultaneously run washer and dryer, two elements on stove, 3 window AC, Hot tub with two jets running, heater heating and filtering, Air Compresser, well pump, heat and hot water, with 4 circulater pumps and well thats still 16kw...

It's a working ranch, and I didn't even turn on the welder. Fridge, freezer, AC, air compressor, dryer, LED/CFL lights, and a 3kw of heaters (to stand in for the well and booster pump). No electric stove. No pool or hot tub. Pretty boring. Normally, the house idles along at about 450W, going up to 2.4kw when the fridge and freezer are running. So, yes, way more than normal, much of it due to the older, inefficient AC.

We have 200Amp service for the house, and a separate 3 phase service for the Ag well(5HP). This was just the house and workshop.

There was some doubt from our utility about whether we needed the amount of grid tied battery backup that we plan to install... Just because we are routinely frugal doesn't mean that demand isn't there. We tend to need backup during fires and winter storms, neither of which is a low load scenario. Unfortunately, we are likely to need more backup than you could really get out of a large propane tank, and permanently installed diesel generators aren't permitted here. Batteries aren't perfect either, especially as they can't be charged by both solar and a generator. That's a whole other discussion.



All the best,

Peter

 

[Industrial Toys]

Most people think they need more capacity than they actually need. But, it's also a matter of managing loads, and if you can't, it can put you (unfortunately) into a much larger set.

Depending on the engine, I would consider throwing all the computer garbage, in the garbage and making the rig simpler. Analogue controls. Just, if the engine is computer controlled, I wouldn't even know where to start. I'm sure someone else would. You need to rely on a generator and if you need to rely on someone to make sure it works, that is a problem.

It could be my imagination. But it seems some companies are using this Corona Boogeyman to be able to pick and choose where they have and don't have resources available.

 

[5030]

With a standby / auxiliary genset, running below rated output decreases the efficiency of a unit (and increases the fuel usage as well) and because they are electrical in nature, all will have electronic controls except a PTO unit but that will also have limited electronic controls.

 

[Industrial Toys]

It all depends how handy one is. If you need backup and have no experience or ability to work on the equipment, then you are really at the mercy of someone elses technology, service (or lack thereof) and worst of all, old man Murphy!

 

[grsthegreat]

With a standby / auxiliary genset, running below rated output decreases the efficiency of a unit (and increases the fuel usage as well) and because they are electrical in nature, all will have electronic controls except a PTO unit but that will also have limited electronic controls.

?. Not sure what you mean by this statement. I had an actual fuel use gage set ip on mine during last run of 14 hours. Max output was 5.8 kw on a 22 kw unit. Normal max fuel use at 100% output can be up to 3.25 GPH. I averaged about 1.2 GPH. I DIDNT see any degradation of the efficiency. I have a program that shows real time frequency and rpm and power output. All were absolutely spot on. Now, if it were a diesel unit running at 25% that might cause some issues.

Oh, and the reason my gen was running during the day was due to the wife having her quilting group meeting in basement. I left gen running while i was out clearing some downed trees blocking the road into our development with the tractor. In this particular example, a pto generator would not have worked for me. Dont want a mad wife .... if you want a trouble free life.

 

[ponytug]

I hear you on electronic complexity. For better and worse, modern engines come with computer controls. The upside is better fuel efficiency and lower emissions, and the downsides include having enhanced complexity. I had a CAT3126 engine die on me because the fuel injection computer died. (fixed with a new ECU-after being towed) Certainly on standby generators, I prefer simplicity over complexity, but I have had simple generators do odd things like throw a valve rod- not something I had stocked as a repair item.Then again, I have backup backup generators.

Diesel engines have a much lower impact of reduced load compared with ignition engines. So, you do get significantly reduced fuel consumption with load reductions. Most non-inverter generators are constant RPM units. Inverter units have much greater abilities to throttle down, and reduce fuel consumption. The trouble with underloaded diesels is that they are prone to wet stacking (carbonizing condensate in the exhaust).

If my neighbor wasn't 80, I might suggest something like a MEP-803A, with an automatic transfer switch, but she is. She and her ninety year old husband aren't particularly mechanically inclined. Hence the Generac, with an automatic transfer switch and automatic engine controls.

All the best,

Peter

 

[ponytug]

Update:

I had a look at the installation today and a couple of things to share.

One, the required pipe is inch and a quarter NPT, and the underground pipe is that. But coming out of the ground, the installer reduced it to one inch NPT to feed a second regulator (gas to gas) in the midst of this one inch pipe. (Honeywell 1813, available in 1 1/4" ) and then through four 1" elbows and about three feet of pipe before feeding it into the 1 1/4" inlet on the generator.

Second, there is, of course, a second regulator, liquid propane to gaseous propane, at the propane tank. It is specified as being able to supply the necessary 240cu.ft./hr that the generator needs. There is about ten inches of 3/4" NPT pipe at the regulator.

Third, apparently the generator initially started up ok until they added significant load to it, when it started surging. Many tech visits since have been unable to fix it, and other errors are / were being thrown.

I have no idea what either regulator is set to for pressure. Any suggestions?

Is it possible that the undersized pipe or second regulator, or both, would cause the surging issue?

All the best,

Peter

 

[grsthegreat]

all propane installations use 2 regulators. a primary one at tank that allows for high pressure and another at generator that drops pressure to meet generator requirements. that unit needs a 2nd regulator that can provide up to 605,000BTU of fuel and the unit has to allow between 7-14" water column of pressure at start up and running. this level is not supposed to fluctuate more than 1" on the meter. do you know weather anyone actually used a manometer while starting and running?. if there is a surging issue i can almost guarantee its a fuel issue. personally i see so much wrong with that picture, its amazing. generac recommends at least 10 feet of 1-1/4" pipe between regulator and generator to allow for a storage area for fuel to assist with start up. second, i do not see any type of a drip leg to protect system from contamination. third, that looks like galvanized pipe which is not supposed to be used on gas systems (need black iron pipe. galv pipe can create flakes of galv coating entering system among other stuff), and the instructions clearly state to not bend the flex pipe, and to not attach flex pipe directly to the generator feed. you need to cross reference regulators to see if they can handle the huge load that unit puts on system.

an d one last thing....but very important. did the installer reconfigure the unit to run on propane. i have run into this problem before, on both the liquid and the air cooled units.

i just looked at a 48kw installation manual, and the chart specifically says no pipe smaller than 1-1/4" no matter what the length of installation.