Generator Quitting on Low Voltage

[e57]

The manual lists the following problems that could cause a Low Voltage: restricted fuel flow, broken or disconnected signal lead, a failed alternator winding, control panel CB is open, generator is overloaded. Since the house is empty it can't be overloaded.

This thing is puny. 10k is not a lot... Even if the house is empty - what is it connected to? The 'idiot lights' - (which is what they are often reffered to - not implying you are...) may just be telling the truth - I would eliminate that first... Even if you may be there measuring voltage - one of two things could be happening while you're standing there.

1. Your meter is not fast enough to catch a voltage dip that the generator senses due to the applied load.
2. The applied load that would cause a drop in voltage is/may be cycled in an 'off' state. Like a refer that is already cold, or a heater when it is already warm... Starting a motor too large, or doing so across a reduced or resistive connection could act very much the same way.

Eliminate the obvious - One you're certain it is not something like that would I go start looking deeper or ordering parts you may not need.

Then I would seek to replicate the problem while I'm there - and investigate that... Which set of controls is shutting it down - the transfer sw, or the generator? Focus on how that senses voltage.* Then go from there. Swapping parts until it works can only cost money and time.

And I'm sure you may have already called the manufacturer - they usually deal with the item in particular...

*FWIW I used to work on generators in the service, a few of them had some round about ways of sensing things - like 'engine speed' sensed by Hz - seems logical until something on the load changes the sensed Hz for reasons unrelated to actual 'engine speed'... Some flaws in air field lighting dimmers would knock out the generator due to 'over-speed'.

As far as connection issues go - WD-40 is not really a 'fix' - infact over time may do more harm than good. Is an oil, a dirt magnet, and does little to improve the connection once it drains away. Physically clean connections - flush with contact cleaner - repeat... Then coat the connection in dielectric or dielectric/silicone grease.

 

[JWCELECTRIC]

Mk,

You could also check to see if the voltage regulator is operation properly. Check with manufacturer on test that you could perform before you send out the Techs.

 

[danickstr]

since the only thing that changed is the gas, I would still look at that. The thing is, if the gas is trickling in, it will run on no load.

A lot of times old plumbers would put in a big pipe, since reservoir tanks are illegal, but a 4" pipe for 10 feet is not. This allows the gas to have some extra during heavy draws. Also, if the line in not clear due to a clogged area, it might just starve on heavy load.

I would want a 20 dollar pressure meter near the intake before you go ordering stuff and running up lots of hours.

 

[problemsolver600]

Natural Gas lines do freeze!

Natural Gas lines do freeze!

Twice in the last two years I had customers who stated that their natural gas lines had been infiltrated with water and froze up.

As a Generac techician, i would definitely first check the pressure.

Gary

 

[Mgraw]

I had a call 20+ years ago about a heater that would not light. Checked the gas valve and had voltage. Pulled the valve and water ran out. Had to blow out the line, dry out the valve and the heater worked.

 

[hillbilly1]

Low gas pressure/volume will cause that problem, It will run fine without load, but when loaded up the engine is staved for fuel and bog down. I have run across that a couple of times, One time on a commercial job, the generator (80 KW if I remember correctly) would shut down when the load was transfered to it. The generator tech swore up and down that we had a fault in our load (480 volt). I turned all of the load off, then brought it on one breaker at a time. It shut down with about 30% of the load on it. Started it back up, then started turning the load back on from the other side of the panel, not turning on anything I had turned on before. Again at about 30% load it shut down again. I went outside to tell the generator tech that it was on his end, when I looked down and seen that they had run a 3/4" low pressure gas line to it. The plumber had run too small of line to it. Don't know why the gen tech had not checked that first.

 

[mkgrady]

Thanks for all the replys, but I think most are not honing in on my problem.

The generator runs very well even with a load or a substantial load. I just can't get it to transfer in the auto mode.

When left in the auto mode, I kill the normal power. The ATS opens the normal relay but does not close the gen relay. After a half minute or so the generator quits and sends a low voltage fault code. This is despite the fact that the gen is putting out 245 volts to the gen relay.

If I run the gen in manual mode and kill norm power the ATS switches to gen and everything runs great off the generator.

This seems to tell me that I don't have a fuel problem. I'm stumped and the manuals provided with the gen and ATS do not provide a lot of info. Tech support at Briggs & Stratton have not been very helpful. They told me was to change the gen relay in the ATS. I don't buy that as it is working when it receives voltage at its coil. They recommended I change the control board. I did and that did not change anything. The last thing they told me was that they did not understand why the ATS failure to transfer would shut down the gen.

I have gone to generator forums but they all seem to deal with Generac and not B&S. I got lots of ideas like I have here but nothing has lead to a fix yet.