TM Electrical Systems

[Bill]

RV electrical systems - two kinds

All RVs have two electrical systems. One is based on 120 volts AC, like power in your house, and therefore referred to as "house power". RVs do not have their own source of house power (although one can be added), so you have to plug the trailer itself into an outside outlet to bring in house power, just like you would plug in a lamp or a coffee-maker in your home. How do you plug it in? Your Elkmont has a big black outside cord near the rear, with a special plug on the end that matches a special outlet in a campground. (Do not plug it into a dryer outlet or other 240 volt outlet!) With an adapter, you can also plug the black cord into a normal household outlet in your home or garage, though that has a somewhat lower power capacity.

The second RV electrical system is based on 12 volts DC, like the power system in your car or truck. Since the power source is a battery, it is often called "battery power". An RV always has its own built-in battery, and most (but not all) of the appliances and devices in the trailer operate from this battery. And just like any other battery, it must be re-charged as you use its power. It is helpful to think of all the 12 volt devices as powered by the battery, and all the rest of the related circuitry as just various ways of keeping the battery charged. For example, if your trailer has solar panels, they can provide recharge power. Also, the trailer has another big black cord up near the hitch, that plugs into your truck. When plugged in, this cord brings in 12 volt power from the truck to charge the trailer battery. Finally, the trailer has its own built-in battery charger, that is active when you plug the trailer into house power.

All this is automatic and transparent to you. More info in the next post.

Bill

 

[Bill]

How the two electrical systems are used

Hello again ...

The only things that operate solely on house power are the air conditioner, the household-style outlets, and the built-in battery charger. Those won't work unless you plug your trailer into an external source of house power. Other than those, all of the TM lights, and most of the small appliances including fans, radio, water pump, and other small appliances, operate exclusively on the battery-power system. An exception is the furnace, which uses gas to create heat, and a 12 volt fan to blow it out into the room.

Some of the appliances have the option to operate from different energy sources - you get to choose which. These include the water heater (house power or gas), and the 3-way refrigerator found in collapsible TMs (gas, house power, or battery power). I think the Elkmont refrig, being bigger, is 2-way only (gas or house power, but not battery). A quick glance at its front panel will tell you for sure.

The Forum has diagrams that outline all this, including a summary diagram at

https://www.trailmanorowners.com/forum/album.php?albumid=8&pictureid=1969

To reflect the basic factory configuration, this diagram does not show the solar power system. If present, the solar charge controller connects directly to the + post of the battery. And for simplicity, certain battery power circuits such as the break-away switch, the propane/CO leak detector, and an electric tongue jack if you have one, are not shown.

Those are the basics. There is no need to memorize all this, as long as you are aware of the multiple systems. TM owners are a creative bunch, and have created lots of mods and upgrades to the electrical systems. These will appear in the Electrical sub-forum, and I will let you page through them at your leisure.

Bill