Skip to main content ↑ ↓
Topic: generator power surging, but engine running fine (Read 697 times) previous topic - next topic

generator power surging, but engine running fine

I looked through several pages of posts on genset problems, but did not find any like I am running into.

I crank on the genset and it runs great. After the ordinary time lag the ATS kicks in and the monitor says it is putting out good electric.

After running for 3-5 minutes the monitor shows the voltage start fluctuating, and then the ATS kicks out.

During the entire process the genset sounds like the rpms are consistent and no great bogs on the system.

Any ideas?

Thanks,

Len
Len and Deb Speiser
1999 U270 36'
2017 Jeep Wrangler Unlimited
You're either on the bus, or you're off the bus!--Ken Kesey
If you're lucky enough to live in a bus, you're lucky enough!

Re: generator power surging, but engine running fine

Reply #1 –
Would narrow it down to the brushes or voltage regulator,make sure all connections tight on ATS.If you have the manual check
the troubleshooting pages.If all else fails call power tech and try and get the tech he's been helpful.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: generator power surging, but engine running fine

Reply #2 –
Add, check connections generator to coach wiring to the list.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: generator power surging, but engine running fine

Reply #3 –
You have the same symptoms I had when I lost the regulator. And when I installed the new regulator with the same wire match up as  the old one fried the generator head. Your year being the same as mine, yours is probably brushless. Jeff at PowerTech can help you trouble shoot to see if it is the regulator.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: generator power surging, but engine running fine

Reply #4 –
I agree with craneman, but ONLY after verifying that generator to coach wiring and connections in the ATS are clean and tight.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: generator power surging, but engine running fine

Reply #5 –
Are the voltage fluctuations random or cyclical?  Random would point to a connection or regulator issue. If they are cyclical, looseness in the generator head could be the culprit.
Steve DeLange
2005 U320T 40'
Pearland, Texas

Re: generator power surging, but engine running fine

Reply #6 –
They seem to come on after 3-5 minutes of fairly consistent output. Things will be going along fine and then start jumping up and down.

I checked the ATS connections and they are fine. I have not rolled out the genset to check all of the connections on it yet.
The generator has less than 900 hours on it.

Len
Len and Deb Speiser
1999 U270 36'
2017 Jeep Wrangler Unlimited
You're either on the bus, or you're off the bus!--Ken Kesey
If you're lucky enough to live in a bus, you're lucky enough!

Re: generator power surging, but engine running fine

Reply #7 –
Last spring mine was doing the same, run normal for about 3 to 5 and then voltage jumped up to 160 or 170 on both legs, Progressive EMS would throw it off line. Isuzu engne always sounded normal. I would follow Brett's advice and then call Jeff. Voltage regulator is specific to brushless or brush generator, and according to model. Mine a late 1997 Protech 8Kw. Voltage regulator solved the problem. 625 hours at time of problem. Have put another 100 hours with clean, stable voltage. Did have to tighten the fan belt because it shut down from high temp, as it was supposed to.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: generator power surging, but engine running fine

Reply #8 –
Cyclical voltage swings would have me looking at the zener diode in the voltage regulator. May be getting hot and failing. I had a similar problem on my bigger standby gen. Two dollars and a few minutes soldering had it like new.
95 U300SE

Re: generator power surging, but engine running fine

Reply #9 –
These regulators are hermetically sealed. Filled with some kind of epoxy.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: generator power surging, but engine running fine

Reply #10 –
You don't comment on how high the voltage fluctuates. Higher voltages are a symptom of voltage regulator failing. Changing regulator can be as simple a plug swap or as difficult as non-plugged wire connections that need to modified. Just read instructions from Power Tech new regulator.
 

Re: generator power surging, but engine running fine

Reply #11 –
Quote from: Barry & Cindy –
You don't comment on how high the voltage fluctuates. Higher voltages are a symptom of voltage regulator failing. Changing regulator can be as simple a plug swap or as difficult as non-plugged wire connections that need to modified. Just read instructions from Power Tech new regulator.
Should put read instructions in bold print. No mention of the ground wire that fries the generator. The instructions if followed exactly will get it done. Do not use the terminal strip in the control box under any circumstances.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean