my standby generator is acting up

This is probably the longest of long shots, but I'm often amazed by the knowledge on this group, so here goes...

I've got a small (7kW, Briggs & Stratton) standby generator. It's about 6 years old and it's only had a few hundred hours of use. Other than one warranty thing when first installed, it's worked flawlessly... until now. It starts up fine, but after a couple of minutes it stops with a "low voltage" error code. The manual has the following info:

"This condition is caused by a restriction in the fuel flow, a broken or disconnected signal lead, a failed alternator winding, the control panel circuit breaker is open, or the generator is overloaded."

The whole thing seems kind of fishy to me, since the voltage in the house measures just fine before it shuts down. Also, a fuel problem seems unlikely to me (it runs on propane, and it's a fairly short run from the tank), I'm sure the generator is not overloaded, and there does not seem to be any circuit breaker issue. I don't know what they mean by a "disconnected signal lead" (what "signal"?), so any hints there would be appreciated. Also, how likely is it that the alternator would go bad?

Btw, I installed it myself, including wiring the automatic transfer switch (_not_ a DIY project for the faint of heart). Apart from the generator, I've probably rewired at least half of my house. So, although I'm not an electrician, nor do I play one on TV, I'm not afraid of doing some electrical work.

Any and all ideas will be appreciated.

 

  Only experience I've had with a generator not working is, went out to run my genny at the time, started fine, ran fine, noted the runtime in the counter.  I came back 20 min or so and checked the run time. it didn't change!  so I grabbed a drop light to plug into one of it's outets.  Lamp didn't turn on.
  Generators motor was still running, but no voltage was being made.  I found the wiring plug from the generator part that supplies the voltage to the gennys panel, and measured it while it was still running. Got 0 nada on the 2 terminals.  The generator part failed somehow.
 Took it back to Costco as it was less that 4 months old at the time. Itt was a Honda 9500 power something or other, so it wasn't a inexpensive generator.  I was surprised it stopped making voltage!

My experience with a propane generator with those symptoms is that you need to adjust the metering valve.  That's the control for fuel flow after the last regulator before going into the carb.  Seems the adjustment is either set for good starting or for max power once warmed up. 

Also, propane can become contaminated with debris and water.  Try flushing propane through the system by removing the line to the motor and opening the tank, then pushing on the primer button on the back side of the regulator.  (It's like a priming button)

Also, try a different propane tank and see if it's a fuel issue that way too. 

Propane is sometimes contaminated and can cause problems.

Here is a photo of a propane kit.  A the top of the photo is a Tee fitting with a knob on the right side.  Try adjusting it. 

Check your systems exciter wire. That's what they mean by Signal Lead.

I'm with Jerry those propane systems in a fork lift can freeze up. I'm not a mechanic. But that silver Disk has a diaphragm that could have a Pin hole. Check youtube on a propane fuel system. If the system runs great then shuts down ( engine stops ) I'd be looking at the Propane system. The ones we dealt with, use the engine water, to keep it from freezing it up. What keeps this one from freezing up?

What the others said - or -Six years - have you replaced the battery. Our Generac has had a lot of problems. Anything with a digital display or a standby mode will cause a drain. When we were using ours using it over a period of days it would start a few  times then quit. Even a Solar panel wasn't enough to keep it going. The problem would be more acute if the battery was old. Sagging voltage can also play havoc and result in false diagnostics

Thanks for the suggestions. Based on this and some other info I found online, I'll start with the propane line and check for issues there. I also remember that we've had some issue with the pilot light going out on our propane heater, so maybe some crud in the line...

If that doesn't do it, the battery is next, then a couple other electrical things to inspect. If none of those do the trick, then I'll have to break down and pay to get someone out here who has proper diagnostic tools. I want to avoid that, since it'll cost more than $200 just to find out what's wrong---I hate to waste that kind of money on anything that doesn't catch fish...

Be careful sometimes it can cost more to fix than a new one will cost. I run two hondas now because they are easy to move. Than my old 5500 watt generator. 

you may want too check the ground fault interrupt circuit if the other suggestions don't fix the problem

Be careful sometimes it can cost more to fix than a new one will cost. I run two hondas now because they are easy to move. Than my old 5500 watt generator.

Yes, I'm not eager to spend any money to get this fixed, since I'd like to upgrade to something slightly larger and  quieter...

This is strange... We just got the propane tank filled. So, I decided to test the generator again, and it seems to be working fine.

The propane tank (250 gallon variety) was at about 30% before, and the generator stopped with an "low voltage" error after a minute or 2. I tested it several times, so I don't think it was a fluke. Now that the tank is full, no problem.

Any ideas? Is it possible there could be some dirt in the line, and the added pressure of a full tank is able to overcome that? If so, it would seem like the clog must be between the tank and the pressure regulator.

If it starts off the battery, then the battery should not be a problem. Look into fuel supply and alternator. Easy to check the alternator. Grab your volt meter, if a 12v system it should charge above 12. If 6v it should charge above 6. Unless there is a fail safe of sorts, the low charging alternator should not cause a shut down. Until that is that the motor cant run because its battery is depleted, but then it wouldn't start afterwards.  Peculiar.

Any ideas? Is it possible there could be some dirt in the line, and the added pressure of a full tank is able to overcome that? If so, it would seem like the clog must be between the tank and the pressure regulator.

A full tank has exactly the same pressure as a near empty tank.  That's the way a gas compressed enough to turn liquid works; the pressure where it turns to vapor remains constant, so as long as there is ANY liquid propane in the tank, the vapor will be the same.  Propane turns to liquid at -44 degress or at 128psig.  At a pressure less than 128 the liquid turns to gas.  So as long as there is any liquid propane in the tank, the tank will be at 128psig.  (That assumes a relative ambient temperature of 60 degress.  Remember, propane is a liquid at -44 and therefore would have zero pressure if it got that cold outside where your tank is.)

Then there's the regulator.  Those fail quite often.  Most propane regulators are set for 11" of water column.  That means, if you take the hose from the regulator and put it in a bucket of water, then turn on the propane tank's valve, there will be bubbles.  As you lower the hose into the bucket, the bubbles will stop when you get the hose outlet to 11" below the water surface.  That is the pressure you want and is easy to check with a 5 gallon plastic bucket since they are more than 11" deep.  Some regulators are adjustable, but most are not.  Regulators are pretty much universal and can be picked up at any place that sells BBQ's, like Home Depot for example. 

Once a regulator is proven to provide enough pressure, 11" WC, then there could be the question of volume and fuel contamination.  Since the tank is never empty, and liquid propane is 128psig under pressure, the only way the fuel can be contaminated is with the delivery.  In other words, someone sold propane with water in it most likely.  Adding more propane to your tank with GOOD fuel diluted the contamination to a point that it no longer affects the running of the generator.   

That's my guess anyways....

This is probably the longest of long shots, but I'm often amazed by the knowledge on this group, so here goes...

So true!  Thanks for the info on how a regulator works and how to test it Jerry!  That's great to know!

Any ideas? Is it possible there could be some dirt in the line, and the added pressure of a full tank is able to overcome that? If so, it would seem like the clog must be between the tank and the pressure regulator.

A full tank has exactly the same pressure as a near empty tank. 

...

That's my guess anyways....

That makes perfect sense. Thanks for the details and especially the DIY pressure check. I'll test the regulators---there's one regulator at the tank itself, which is higher pressure, and one by the generator which is supposed to be set to 11" WC (a 2-stage setup). I'd suspect the higher pressure one might be where the problem is. I wasn't here when the propane guy came this time, but that could easily have gotten jostled around. And come to think of it, the pilot light on our little propane heater has gone out a few times recently. That heater is on a different (low pressure) regulator, but it taps off of the same higher pressure regulator by the tank.

If the higher-pressure regulator is defective, is it something I could get at HD?