Fan Constant On

[Tinkerman2]

Hello,

I'm kind of new to TC. I have a 2015 Northstar 650SC. Why does the fan where the electric box is constantly on? It's off if I turn off the Refrigerator circuit breaker.

Is it supposed to be on all the time?
Thank you.

Alex

[Old-Biscuit]

Fan is to cool down the converter
Fan comes on when there is a High DC Demand and converter is generating heat

Fridge.......brochure shows Three different Dometic fridges ALL 3-way
AC, LP and DC
DC is a HUGE Drawn on DC Battery/System
Otherwise the DC to fridge for controls when using AC/LP is minimum

Check the fridge controls and make sure it is NOT in 'DC Mode'
*DC Mode is for when traveling so vehicle alternate can maintain DC demand
*Some newer fridges use AC has Priority then Swap to DC vs LP
(Should be AC then swap to LP and DC be selective not auto but logic got changed.....stupid!)

Post Model of fridge

[Tinkerman2]

Originally Posted by Old-Biscuit

Fan is to cool down the converter
Fan comes on when there is a High DC Demand and converter is generating heat

Fridge.......brochure shows Three different Dometic fridges ALL 3-way
AC, LP and DC
DC is a HUGE Drawn on DC Battery/System
Otherwise the DC to fridge for controls when using AC/LP is minimum

Check the fridge controls and make sure it is NOT in 'DC Mode'
*DC Mode is for when traveling so vehicle alternate can maintain DC demand
*Some newer fridges use AC has Priority then Swap to DC vs LP
(Should be AC then swap to LP and DC be selective not auto but logic got changed.....stupid!)

Post Model of fridge

Thank you. Fan continues to run despite fridge being off.
Perhaps the battery is charging due to being low at 12.67V??

[Old-Biscuit]

12.67VDC is over 90%

Where/How are you measuring Battery Voltage?

*Voltage will read higher when charging and for couple hours after charging cycle

Once again ----- Model of fridge????
Was it running of the DC Element?

Your converter is a 25A charger......so it will run frequently when using DC devices

[Tinkerman2]

Originally Posted by Old-Biscuit

12.67VDC is over 90%

Where/How are you measuring Battery Voltage?

*Voltage will read higher when charging and for couple hours after charging cycle

Once again ----- Model of fridge????
Was it running of the DC Element?

Your converter is a 25A charger......so it will run frequently when using DC devices

Well, I disconnect the battery and the fan stopped running. This tells me something is wrong with the battery although it was read 12.67 VDC with the negative cable disconnected.

The battery is only 1 year old but been outside all Winter long.
Converter DC output is read 13.6 VDC.
I'm charging the battery and will try again when the battery is full.

[Fridge Defend]

First, we do not advise using the 12VDC heater on the fridge while driving.
The 12VDC heater can overheat the fridge boiler, it is stated in the user manual in so many words, but not directly.

Next, due to the formula P=V*I, as your battery voltage goes down, the current has to go up to deal with the load. So what!

So your fan comes on due to the fact that more current in the inverter results in more heat. The fan is doing its job from what I see, and the battery is doing its job from what I see.

Hope this helps you understand the physics behind the fan running, and gives you a safety tip based in the use of 12VDC to heat the boiler in your fridge, all combined with real world driving data collection.

[laj]

So if i understand you correctly my 3way was never designed correctly.

My manual says never to run it on propane while driving down the road, but to run it on DC instead.
Explain

[Tinkerman2]

I told you guys the fridge itself was off. The Fridge circuit breaker was the only thing on.

[Old-Biscuit]

Originally Posted by Tinkerman2

I told you guys the fridge itself was off. The Fridge circuit breaker was the only thing on.

Fridge Circuit Breaker is 12V0AC and has NOTHING to do with the cooling fan for converter

So if you would answer some questions ASKED you can get better responses

Model Of FRIDGE?


Fan stops when you disconnect battery.....charger is NOT running so no heat requiring cooling fan

You need to check battery water levels and specific gravity on EACH battery cell
One of the cells could be bad causing overcharging
*Converter output when charging S/B 13.6VDC ----converter doing it's job

[Old-Biscuit]

Originally Posted by laj

So if i understand you correctly my 3way was never designed correctly.

My manual says never to run it on propane while driving down the road, but to run it on DC instead.
Explain

3 way fridge
AC Priority
LP for boondocking and while in transit
DC while in transit only due to high DC Demand
***That is what the DC Heater is designed for ---to be used while in transit (DC heater elements are less wattage then AC elements but generate sufficient heat to MAINTAIN cooling in fridge while traveling)

10,000s of RV fridges are operated on LP while in transit


What is the Brand/Model of your fridge?

[laj]

Sorry Old-Bisquit, can’t tell you the model, but its a dometic. It. is a 2020 model. use to run mine on propane all the time in my CC on the road, also dometic. I was surprised to read this in my owners manual.

[ArtJoyce]

I had a camper and all you had to do was turn a few 12v lights and the fan would come on.

[Tinkerman2]

Thank you all who chimed in.
All is well, The fan was on for one reason the battery was low from sitting over the winter (disconnected)
After the battery was charged overnight and reading around 13.06 VDC. No more converter fan stay on all the time. Everything was okay.

[Old-Biscuit]

Originally Posted by Tinkerman2

Thank you all who chimed in.
All is well, The fan was on for one reason the battery was low from sitting over the winter (disconnected)
After the battery was charged overnight and reading around 13.06 VDC. No more converter fan stay on all the time. Everything was okay.

AH....nugget of info
Battery out all winter....that will cause a converter to run