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Topic: Analog Voltage gauge oscillating - any harm? (Read 387 times) previous topic - next topic

Analog Voltage gauge oscillating - any harm?

The Powerwatch analog A/C Voltage gauge on the Heart panel is wobbling between115 and 125v with the 8kw gen running powering one of the roof mount original equipment a/c units.  The a/c compressor is running continuously at 92F here in Killeen Texas (we are in a covered metal pole shed (thank god)).  Glad to have a ducted ceiling so we can run the back a/c and pipe it forward to reduce noise.

Wondering if this is a sign of problems ahead or just a "feature" of an analog gauge.  We don't run the generator often and it and the a/c seem like they are running smoothly and normally - we serviced both recently.  Polarity is correct and believe it or not, the generator only has 60 hrs on this 1997 U270....runs and starts like new. 

The RV park we are in is having their own issues....yesterday it was a burned up connector on a meter and today one of the transformers is being replaced (which is why we are on the generator in the first place with shore power unplugged).  I think Texas may be on the verge of a brownout as the afternoons here show a dip in voltage on shore power down to 110v and a little warble to the analog voltage meter...... we survived the big freeze here and now this...what a place!  Everything is original and working on our coach...hopefully it will stay that way.  And info on this appreciated.



Carl and Kathleen
Killeen Texas
1997 U270

Re: Analog Voltage gauge oscillating - any harm?

Reply #1 –

First of all, 60 hours on gen means gauge has been replaced or malfunctioned or gen has not been used very much. Generators like to be used so you do it a favor by using it.

Between the analog meter being your only voltmeter and its needle movements, this could be seen as normal. Generator speed control manages 60-cyle frequency, so as long frequency is stable, gen is running correctly.

This $7-$10 Amazon meter would be helpful to understand gen & shore voltages:

Flat US Plug AC 80-300V LCD Digital Voltmeter Voltage Measuring Monitor, AC...

Or this $15 Amazon meter that displays both voltage AND frequency:

LM YN Digital AC Voltmeter AC80-300V Frequency Counter 45.0-65.0HZ LCD...

On another point if you unplug the small white connector in the rear roof air, the rear AC will cycle on thermostat room temperature of the front of coach, instead of cycling on bedroom temps. We used to find that the bedroom cools down faster than the front living space. Putting a switch on the connector wires will allow easy change from bedroom to front temp sensor. Also, if the rear bedroom temp sensor wire is connected to front roof AC, you can run the front AC at night for a quieter operation while maintaining temp in the bedroom. These wiring changes are easy to make and have been discussed on the Forum.  We have instruction if needed.

We also have a 1997 U270 with 8,000-watt gen. Our analog meter also oscillates sometimes.

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Re: Analog Voltage gauge oscillating - any harm?

Reply #2 –
If you only have 60 hours on the generator make sure you check you rear
bearing.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Analog Voltage gauge oscillating - any harm?

Reply #3 –
Quote from: Carl Cox –

Wondering if this is a sign of problems ahead or just a "feature" of an analog gauge. 


Not exactly a "feature of the gauge" although when trouble shooting an analog gauge sometimes gives better information than a digital gauge simply because you CAN watch the needle swing.

If your generator's engine has a mechanical governor, a drop of oil on each pivot point may do some good.  As will ignoring the volt meter and just running the generator. 115-125 is a normal voltage range for the AC mains, so you won't be hurting anything, but we're all used to the power company supplying one or the other and not everything in between.

FWIW the closer you adjust a mechanical governor to eliminate voltage sag, the more likely you are to cause it to hunt for the right speed.
1992 Foretravel Grand Villa
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1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
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