Low Voltage

Hey Guys,

Generator starts up all is good... house AC panel comes up inside coach all voltage and amps are within normal limits everything looks good.
Then after 5 minutes of running the generator the transfer switch kicks out due to low voltage. the generator is only putting 88 volts out on both legs.

I've replaced the AVR (automatic voltage regulator) still no luck.

Pro Tech 17.5 gen set with 2533 hrs Any ideas ?

I'd give Power Tech a call. Most say they are very helpful.

There is an adjustment on the regulator. Mine was doing that on one leg and I looked up a qualified service co. for Power Tech, took it to them and they adjusted it.

Thanks Danss
I tried that but it still continues.

Hey Gill
I called them and they think it might need a whole new gen head ( rotor , stator and so on , they said it comes as one whole unit )

thanks guys

Jeff great to talk to u. A new gen head is not as difficult as many may think.

I see u have a stacker and im guessing u could be a handy guy in the garage.

It does separate from the engine as an assembly pretty easily.

If u have a fork lift u can unplug and pull the gen from the bus by undoing as few as about a half dozen things. The battery cables the fuel lines, the 4 power leads from the bus with some smaller phone cable remote connections and that's about it. 4 bolts through the floor. Its not a rush to have it out before lunch.

Once out it does come apart as an assembly. All that gets undone is 5 or 6 bell housing bolts and 5 or 6 flex plate bolts, all completely accessible . And that's it. Once u have the gen out on the garage floor it is minutes to unbolt and separate the 2 halves.

If u get your ducks in line it is a weekend project.

U will spend just as much time if not more cleaning and redoing whatever stuff in the bay that my require attention. Not a bad thing either.

Be conch, If u have a service center do it I don't see any reason why u could not be serviced in a day or 2 if prearranged.

If it is the power head, know there are multiple sources for compatible power heads. The biggest difference in other heads, or maybe even a new one from PT, is the placement of the electrical junction box.

I've seen Joe do this before. Let me just say easy for some may not be easy for all.

BTW, if the generator does have to come out, that's a great time to recondition the generator box.

Attachment 14660

Attachment 14661

Pictures worth a thousand words here's a 20K head at the bell housing right here. Those are the two sets of bolts you have to remove to split it. The inside ring im pointing to u get those through some duct openings on the side of the housing.

This is a good 20k head but with a ton of hrs. Not sure what's going to happen to it. I might just take it all apart for a few pieces and steampunk it.

Gill, when they send it with the panel relocated that totally complicates the project with about a half dozen fiddly items that need proper engeneering to be moved besause of the generators ability to be slid out.

Attachment 14662

This panel is on top, others r on the side. That's a bigger change than u might think on a gen that's shoved in a hole.

Matathon is a great American manufacturer of gen heads and I've used them. However experiance has taught me that repacing with OEM usually eliminates most if not all of those hurtles. Defiantly look at good pictures of aftermarket heads for location of the electrical panel. That will simplify things tremendously when it's in the same place. Locate specific locations of the "knock outs" . Moving location creates hurtles.

Also some aftermarket heads don't come with the panel. In fact now that u r jogging my memory. I put a Marathon head on Ben Wilmores Liberty. I had to use the exzisting panel the Marathon head had no panel. That also required sizing and dressing all the leads coming from the head. U get it with all leads at about 2 ft and cut clean and u start from scratch.

Hey Joe,

Thanks so much for all the good info on pulling the gen. Sounds like you’ve done one or two.
I think it may be a little more than I want to tackle on my own. I think I’ll just let them do it when I head to Florida in March.

Gill
thanks for your info on the box placement also....good info.