Electrical box fan

[FionaGrant]

Whenever we turn on the range hood fan while connected to shore power, a fan in the electrical box under the fridge starts up.

Turn off the light, the fan turns off.

Seems odd that one light bulb would cause this?

[BuddyRay]

I would agree, that is very strange.
The fan coming on is PROBABLY the cooling fan on your converter (the box that converts 110v AC power to 12v DC). Normally those fans only come on when the converter reaches a certain temperature and needs cooling. It normally takes a significant 12v load to turn the fan on, it's an automatic process.

Perhaps your Converter fan is designed to come on ANY time there is a 12v load. But if that was the case, turning on ANY light or other 12v load (like a ceiling vent fan) would trigger it.

The only other factor is that most if not all of your lights are probably LED and draw very little power. However, they haven't made an LED light that can stand the heat of a vent hood or oven. So those lights are usually incandescent. It may be drawing as much as 5 to 7 watts. So that MIGHT be enough to trigger the fan in the converter.

I think you need to verify exactly what the Fan you're hearing is to be sure.

[FionaGrant]

It is definitely coming from where the converter would be. The box contains all the 12v fuses and ac breakers

[ARoamer]

Originally Posted by FionaGrant

Whenever we turn on the range hood fan while connected to shore power, a fan in the electrical box under the fridge starts up.

Turn off the light, the fan turns off.

Seems odd that one light bulb would cause this?

Not necessarily. There are other 12v loads besides the range light, such as refrigerator, water heater, CO detector, and charging the 12v battery. Turning that light on likely adds enough draw to start the power converter fan running.
The bulb appears to be a incandescent, if it's a issue you may be able to swap it out easily with a LED bulb which MIGHT NOT kick the fan on.

Amazon has them, 10 for $8.99, or maybe your local RV stealership might have them. https://www.amazon.com/Bright-Traile...e95133f20&th=1

[FionaGrant]

Thanks, I'll see if an led helps

[THE MEEKER]

It is working correctly. As BuddyRay said, whenever there is a 12v. load it should come on.

On my 2001 Fleetwood TT, the converter fan would come on when several incandescent lamps were turned on. As soon as they were turned off, the fan would stop.

[RogerR]

I switched my hood fan to LED and the load really went down as tested on my Renogy app where I could see that the little bulb drew almost 1 amp. Plus the converter may be supply power to the battery charge circuit and the total goes over the heat limit. Or your heat limit switch on that fan is a little off on the warm turn on.

[FionaGrant]

It's such a small bulb.

https://photos.app.goo.gl/FShetGSxfhjnwA1S9