Possible electrical issue with lights 2009 Springdale?

[DMKRV]

I have a 2009 Keystone Springdale with a “WFCO Model 8955AN Power Converter With Panel”. My interior overhead lights will work when on battery only. So I assume they are 12V.

This last trip I noticed that while at the campsite hooked up to 30 Amp service, with several of the interior overhead lights on, they would occasionally dim and go brighter. Not a lot, but just enough to notice it. I also noticed the sound of a fan kicking in and out occasionally, coming from the area of the electrical panel.

It may have been doing this before, but I didn’t notice it. The battery is only a year old and shows full charge when I’m plugged into shore power, I haven’t checked it when I’m not plugged in. Is this light dimming/brightening and fan running normal?

Thanks.

[sourdough]

You are probably hearing your converter kick on and off and yes it is normal. Some things to consider; if you don't have 2 batteries I would put them in, a single battery, especially a dual purpose (cranking/storage) just doesn't have much oomph running all the 12v "stuff" in an RV. Secondly I would replace all the lamps with LEDs. It will cut that converter kicking in and out to almost zero. If you are using lots of 12v accessories it will make the converter kick on and off more frequently and deplete your battery(s) more quickly if not plugged into shore power. Also, if you run on 12vdc only for a period of time expect that converter to kick in and run when you finally plug into shore power - it's what charges your battery(s).

[bobbecky]

Some years ago, I replaced all the interior light bulbs with LED's. Prior to this, we could turn on all the lights in the rig and both fans for the converter would start spinning loudly. We would also see the dimming of the lights. After the LED's were installed, we never hear the fans and never see any dimming. If you do upgrade to LED's, be sure to use the bulbs that are rated 10-30 volts DC, because your rig will hardly ever see exactly 12 volts, and 12 volt only bulbs will fail very fast.

[JRTJH]

Let's do a little "math on light bulbs"...

A WFCO 55 amp converter produces 55x12= 660 watts of DC power
A single 921 incandescent bulb uses 20 watts of power.
Five "dual bulb ceiling fixtures" will use 10x20= 200 watts of power which is almost 1/3 of the total converter output. Add a "partially discharged battery" that also puts the converter in bulk charge and you're going to "max out the converter output. Maxing it out and then turning on another bulb or the furnace or the water pump will assure that the "lights dim as the converter goes "over its maximum output".....

What's happening is normal. Not healthy for the converter, definitley putting it at/over max output and triggering the fans to run at maximum speed. Reducing the number of lights is one way to lower the DC power requirement on the WFCO converter, replacing the "power hungry 921 bulbs with LED's is another....

Essentially, your converter is screaming at full power, trying to climb uphill and letting you know that it's "the little engine that could" but might not for long......

[DMKRV]

Thanks guys, I'll replace the bulbs with LED's.