trailer plugged in

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sierramann

Well-known member
Joined
May 15, 2006
Posts
64
Location
Hampton, New Brunswick
here's a stupid question....... when i park my fifth wheel in my driveway between trips i usually leave it plugged into my house. i have noticed that on several occasions a whirring type noise coming from the fuse panel/invertor area. it is also quite warm to the touch. is this normal??? i know that the invertor will keep the battery charged up fully, but should be idle once the battery is fully charged. while the trailer sits there is nothing on, except the fridge, but its ac power.
 

Ned

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Joined
Feb 1, 2005
Posts
25,107
Location
USA
Even though you're on shore power, there are devices that draw 12V from the batteries.  The controller boards in your refrigerator, for instance, still require 12V.  The inverter/charger will also use some 110V power, even when idle, so what you're probably hearing is the fan running.  Since you say the fuse panel is warm, I would say the inverter is located there as well.
 

John From Detroit

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Joined
Apr 12, 2005
Posts
24,798
Location
Davison Michigan
If it warm, the fan on the inverter will run, as the other poster said, there are things that always draw power evein if "off"

In addition some inverters do a "equlize" every so often, (This is good if you have flooded wet cell batteries, not so good with AGM)
 

Kirk

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Joined
Oct 30, 2005
Posts
287
Location
Full-time , Escapee
By far the most common sound from an RV's 12V-dc converter is transformer hum. All transformers have some tendency to make noise and if there is anything at all loose it will vibrate with the 60 hertz frequency. There could be some sound from the fan, but most of them use a little "muffin" fan that makes almost no sound. On the other hand, transformer hum is there whether under load or not, and is very little different under load than not.

As stated, there are things that use 12V power in the RV all of the time. Your refrigerator has a control board that uses 12V-dc power to control the temperature and to choose between 120V or propane to operate the heater. Most, if not all of your lights are powered by 12V-dc so that you will be able to use them no matter where you are. Your water heater also has a control board that is powered by 12V. As a result, it is very rare for the converter to be completely idle.
 

woodartist

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Joined
Jun 23, 2006
Posts
563
Location
Wandering the Old West
Well, in one of my previous lives I had an RV repair business. Most of the issues about noise and heat, as you described, were from the power converter. Keep in mind that you will be drawing some current, even if nothing is hooked up to the secondary. Small, but it is still power....FYI
 
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