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Pexring · 06-13-2014, 11:40 PM

Still trying to learn things about my first Class A. When my Onan 4000 generator runs, my lights get much brighter than when using shore power or 12V. Seems like the generator is putting out too many volts. What's an easy way to check and adjust?

Attachment 65373

94-Newmar · 06-14-2014, 05:51 AM

Post your generator model number.

To check voltage you need a voltmeter; probe any AC outlet. I wouldn't be overly concerned with any reading between 110 and 130 volts AC.

vsheetz · 06-14-2014, 05:53 AM

You are speaking of DC powered lights in the house, right? Check voltage with a meter to see what the difference is with and without the generator running.

Triker56 · 06-14-2014, 05:57 AM

OP is probably talking about his 12V lights.
When on shore power they probably are getting around 12V from your converter/charger.

The generator may be putting out around 14V.
Generator volts won't hurt anything.

mel s · 06-14-2014, 06:10 AM

Quote:

Originally Posted by Triker56

The generator may be putting out around 14V.
Generator volts won't hurt anything.

Other than shorten the iife of incandescent light bulbs.

94-Newmar · 06-14-2014, 06:19 AM

Quote:

Originally Posted by Triker56

OP is probably talking about his 12V lights.
When on shore power they probably are getting around 12V from your converter/charger.

The generator may be putting out around 14V.
Generator volts won't hurt anything.

No, the generator would not be powering the house DC directly. It would be powered through an AC to DC converter/charger. Depending upon which converter type he has the DC output may be proportional to the AC input. In a coach of his vintage he could very well have either a linear or ferroresonant type converter. While early ferroresonant converters were much better at DC voltage swings based upon AC input power, they could still swing enough to cause noticeable light dimming/brightening. Switching type converters (the most stable type) were just being introduced.. if memory serves me correctly it would have been around 1992-1993 but his coach is listed as a 1991.. so yes, it is entirely possible he is experiencing this based upon generator AC output.

johnzuki · 06-14-2014, 06:22 AM

Check the simple things first. My opinion is that he has a battery that is faulty. Battery voltage may only be around 11 or so, but with generator, getting full 12 to 14 volts on dc lights. Check water level in all batteries, then load test them if you have that ability and report back.

94-Newmar · 06-14-2014, 06:24 AM

Quote:

Originally Posted by johnzuki

Check the simple things first. My opinion is that he has a battery that is faulty. Battery voltage may only be around 11 or so, but with generator, getting full 12 to 14 volts on dc lights. Check water level in all batteries, then load test them if you have that ability and report back.

You missed the part where he mentions that the difference he's experiencing is between the generator and shore power, not between any AC power and the batteries by themselves :-)

Pexring · 06-14-2014, 07:46 AM

Both the AC and DC lights are brighter. Well, the only AC light I have is the light in my new residential fridge, but when you open the fridge door you about need sunglasses to look inside with the genset running.

Coach batteries are brand new as of yesterday.

I will get my meter out and take readings. I can also post the model of my converter.

94-Newmar · 06-14-2014, 08:19 AM

Quote:

Originally Posted by Pexring

Both the AC and DC lights are brighter.....
I will get my meter out and take readings. I can also post the model of my converter.

Yes please :-)

TQ60 · 06-14-2014, 09:12 AM

Until figured out limit battery connection or turn off charger as indications are of high voltage on ac side and charger may also be high but until you measure you do not know so turn off batteries

wa8yxm · 06-14-2014, 11:13 AM

To adjust.. I can not tell you since it is an electronic voltage regulator

To check, That one is easy, more ways than I can list

I have a nice Analog meter I got from Camping world
I have a Kill-a-watt (Which is about a kilo-buck worth of meters in a 20 dollar box and has several other useful fucntions, epically in this case)
I have an assortment of Multi-meters (hazard of my hobby).

But I'd go with the Kill-a-watt plug in (The analog cost nearly as much)

Plug it in, press VOLTS and take a reading

Fact: "Standard" for power is 120 volts. Many shore power outlets are a bit.. er.. anemic (Like 82 volts on the surge guard display in one park, That's way too low) just so you know.. 125 is OK , 130 is a bit high.

Pexring · 06-15-2014, 03:06 PM

Finally not raining today so got out my volt meter and was all prepared to check voltages. Except for the first time ever, the generator will not start. The starter just sits there and clicks. Ugh!!

mel s · 06-15-2014, 03:54 PM

Quote:

Originally Posted by Pexring

Finally not raining today so got out my volt meter and was all prepared to check voltages. Except for the first time ever, the generator will not start. The starter just sits there and clicks. Ugh!!

Pexring
That may be caused by low battery voltage.... either the chassis or the house batteries, (depending upon which batteries your coach maker used for starting the generator).
Using the "battery boost" switch may help as it does for starting the engine.
Mel
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