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Generator and voltage question

I suspect the answer to this but want to throw it out anyway.

Attached are picture of the voltage readings in camper with my propane powered generator with one AC unit.  The generator doesn't run smooth and "surges" under load- so probably a tune up in order. 

My question is shouldn't the voltage read higher than the 110V minimum with no load?  This leads me to think the generator itself is needing attention- anyone else experienced it and how much coach $ to fix?

Thanks,
Dan 1989 U280 40'

Re: Generator and voltage question

Reply #1 –
Dan,

First, it quite common for those old analog voltmeters to be off.

So, I would start by verifying with a digital voltmeter.

And, yes, if your propane generator is surging, it needs attention.  First suspect (if it is a liquid LP generator) is the propane regulator.  So, is your generator a liquid LP generator, or do you have a regulator external to the generator itself?
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 and voltage question

Reply #2 –
Quote from: wolfe10 –
First, it quite common for those old analog voltmeters to be off.
So, I would start by verifying with a digital voltmeter.
Another quick way to check generator output is with a Kill-A-Watt meter.  Plug it into any duplex outlet, read volts and frequency (Hz).  It is a very handy tool - commonly available for under $20.

Kill A Watt Meter - Electricity Usage Monitor | P3
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Generator and voltage question

Reply #3 –
Thanks for the quick replies!

Brett- yes, liquid propane with external regulator.  I will start with checking the voltage with another meter (good suggestion above and I have other uses for this!) and then to the regulator. 

I don't think it is so much a meter issue as when on shore power the meter runs about 116
Dan 1989 U280 40'

Re: Generator and voltage question

Reply #4 –
Generators run at 1800 rpm.  That allows a 4 pole generator to produce 60Hz. Output voltage is a function of field voltage. These are generally rotating field generators, that keeps brush current low.  Check your output cycles to insure the generator is actually oscillating.  Oscillating at low power can indicate a loose stator.  Oscillating at high power likely an engine performance issue.  Low voltage is usually a regulator problem as long as you are not at max output.
Steve DeLange
2005 U320T 40'
Pearland, Texas

Re: Generator and voltage question

Reply #5 –
My power watch meter is about 5 volts lower than the generator or shore power actual voltage.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country
 

Re: Generator and voltage question

Reply #6 –
yep, not saying the meter is accurate, but the generator is running about 8 volts lower under load than the shore power under same load (one AC), thus the generator issue.

Have an IMPCO model J regulator currently- going to address that first and see if it fixes.

Thanks to all for the help!
Dan 1989 U280 40'