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

grsthegreat · Sep 23, 2020

dodge man said:
In the case of the OP’s neighbors, it uses very little fuel since it doesn’t work. You would think if it will work with very little fuel pressure the wrong piping wouldn’t affect it.

I had a car with a feedback carb that adjusted the mixture automatically so it doesn’t have to be fuel injected.

The op’s unit may just have never been set on controller for propane. A simple fix. But not having proper sediment trap on a propane system is a certain future failure issue. You would not believe the junk that gets trapped there. Would not want that going thru my carb.

TractorGuy · Sep 23, 2020

Not sure if it's been asked or mentioned but was the installer a liquid cooled certified Generac tech? If so the owner should at minimum let Generac know about the way it was installed.

I will stick with diesel for now. I load mine to near max on a monthly basis to keep it clean. When we have a long term outage we will crank up the oven and bake cookies for everyone every few days to keep it cleaned out. It seems to stay around seven tenths of a gallon per hour no matter how we load or don't load it.

grsthegreat · Sep 23, 2020

Diesel gens are sure nice. If i had more power outages or were subjected to prolong outages like eastern seaboard weather related issues, id have one myself. But in 4 years i only have 50 hours on my generator. Also, where i placed my generator, right next to my patio, i like the clean look of the generac system.

bnold · Sep 23, 2020

Run into gas piping deficiencies on boilers all the time. Incorrect regulator sizing, effective length of pipe incorrect (pipe and fittings), incorrect pipe size, regulator not set correctly, etc...

Sooo many I’ve come across have just matched gas pipe size connection on the unit... Almost never allowable.

Biggest issue with boilers is maintaining minimum pressure (and we are talking 14” wc or 0.5psi) on startup. The initial lighting sequence opens the gas valve a good deal and immediately slows to a low burn rate to start. If the pressure drops below 8 or 10” generally, the boiler controller will fail on low gas input.

CalG · Sep 23, 2020

I'm trying to help an older single gal (in her early 80s) with a 15 kw whole house Generac unit that doesn't keep the battery charged.

After a month or so of once weekly auto runs, there isn't enough battery to start the propane Kohler.

Checking around with a meter, the fuses are both good (5 and 15 amp) and power is getting through after the fuse. The transformer is putting out 15 v.

Any "Usual suspects" to look into? I don't quite get the function of the relay... I need to study the electrical schematic more.

I've got the unit on a battery tender now. stop gap.

Sorry to bring an aside to the OP thread, but it seems such deviations are not uncommon. ;-)

TIA

Industrial Toys · Sep 23, 2020

Most standby generators must have some kind of continuous charging method. You didn't say if it had one and simply wasn't doing it's job or the machine was relying on the excercise time for recharge.

grsthegreat · Sep 23, 2020

CalG said:
I'm trying to help an older single gal (in her early 80s) with a 15 kw whole house Generac unit that doesn't keep the battery charged.

After a month or so of once weekly auto runs, there isn't enough battery to start the propane Kohler.

Checking around with a meter, the fuses are both good (5 and 15 amp) and power is getting through after the fuse. The transformer is putting out 15 v.

Any "Usual suspects" to look into? I don't quite get the function of the relay... I need to study the electrical schematic more.

I've got the unit on a battery tender now. stop gap.

Sorry to bring an aside to the OP thread, but it seems such deviations are not uncommon. ;-)

TIA

I dont know how old your generator is, but since you state a transformer, i assume its around 2008 era generator. i would need a serial number to cross reference it truly.
the older units have a transformer within the generator control panel area, and a relay. the relay swaps between utility supplying power to transformer and the generator windings while running powering the transformer. theres also a battery charge module.

transformer should show 16 volts aprox at both sets of upper terminals. theres 2 set of 16 volt AC output on the transformer. since your getting voltage at transformer, i bet your issue is with the battery charger itself. ive had to replace quite a few of these over the years. you need the serial number of the generator to verify proper part.

It's very possible that the charger is bad. You can test for AC voltage on the input wires at the top of the charger (the smaller 2 wire connector) and should read around 19 VAC. The output is measured in DC voltage and will be the larger 3 wire connector that only has two wires (no wire in the middle spot). Output should be around 13.5 VDC on those 2 wires. If you have AC input and no DC output, the charger is bad. but, before you do this test you should start generator a few times to draw down on the battery reserve. if the battery is fully charged, i sometimes see no voltage at these terminals. best to be sure battery isnt fully charges. the battery charge module is a 2.5 amp trickle charger.

ponytug · Sep 23, 2020

grsthegreat said:
The op痴 unit may just have never been set on controller for propane. A simple fix. But not having proper sediment trap on a propane system is a certain future failure issue. You would not believe the junk that gets trapped there. Would not want that going thru my carb.

Hmmm... I wondered about that. You might notice in the photo that I posted above that the existing, to be replaced, piping doesn't have a sediment trap. What do you recommend? "Tee" style? Screen?

All the best,

Peter