Community Forums

WDW · 04-01-2018, 05:10 AM

A friend of mine had a problem with a 110 light switch in his fifth wheel. He had another gentleman change it, and he chose to replace it with a traditional house style light switch. There’s something in the back of my head thinking there’s a difference in how they work and it does not permit this type of interchangeability. Am I wrong?

gerdutch · 04-01-2018, 05:27 AM

I have changed out 3 of my outlets with house type 110V/USB outlets that work just fine. The difference was the construction of the outlet. The RV style was substandard and fit better in in shallow spaces.

twinboat · 04-01-2018, 05:50 AM

The RV style outlet doesn't need a juntion box in the wall. It is self contained with no wiring exposed.

A home style receptacle has exposed connections and, by code, needs to be in a junction box.

Often times the wall isn't deep enough for a box and tape is not a substute.

I'm not sure if RV wall switchs are self contained or they use junction box's. All of mine are 12 volt.

wa8yxm · 04-01-2018, 06:10 AM

You said it was a 110 Volt light switch (Never seen one in an RV) as opposed to a 12 volt.

THe difference is that the House light switch is more "Robust" than the 12 volt switch since it is designed to "Break" a much higher voltage. So it is better than the 12 volt switch.

If it was a 110 volt switch, then that is the same as a standard house light switch.. electrically that is.

70ChevelleSS · 04-01-2018, 06:18 AM

We have a 120v switch for the electric water heater. It's an RV style switch, contained wires and looks from the back like an RV style outlet.

nothermark · 04-01-2018, 10:01 AM

The RV light switches are rated for 12 VDC not 120 VAC. Significantly less insulation needed, no protection from touching the wires needed. Heavier contacts might be needed but lights don't draw much current so probably not. Don't need to break nearly the arc of 120 VAC so can snap slower and open less of a gap.

Calling 12 VDC parts substandard usually indicates the ignorance of the person making the pronouncement. The requirements are significantly different between 12 VDC parts and 120 VAC parts. Neither one is automatically a better substitute for the other. In many cases the higher voltage part will work *if* it has the current rating.

hohenwald48 · 04-01-2018, 10:20 AM

The OP specifically referenced a 110 light switch so I don't really understand the comments regarding 12 VDC light switches in some of the responses. That usually just confuses and novice whose looking for helpful information. I believe 5th wheels and travel trailers routinely use some 110 VAC light fixtures. Not as common in motorhomes.

Most 110 wiring devices (outlets and switches) in RVs are designed in such a way as to not require junction boxes. These switches and outlets require a special tool to install and are specifically designed to avoid loose connection screws caused by vibrations. Since most folks don't have the special tool they often replace them with standard residential devices.

That's usually not a problem as long as a junction box is also installed to cover the live connecting screws on residential devices. Loose connection screws due to vibration are seldom a problem but they can be.

Jim18655 · 04-01-2018, 10:22 AM

DC arcs are harder to break since the voltage remains high the entire time. An AC switch has 'help' since the voltage is at zero volts two times during a cycle. An AC switch can operate (open) slower because of this. DC ratings on switches, if they have one, are usually, but not always, less than the AC current rating. Remember, we're switching power not just voltage. A low voltage DC circuit carries more current to do the same work as a 120v circuit.
Protection from the voltage is more critical on 120 VAC, due to the shock hazard, but either could short to ground and cause problems, including fires if over heating occurs before a fuse blows or breaker trips.

nothermark · 04-02-2018, 05:46 AM

Do they put 120 VAC lights in any RV? All I know is that we have had to explain to many folks that their lights run off batteries.

As far as DC arcs vs AC arcs go agreed. It's the difference in voltages to begin with. 12 VDC vs ~180 Vpeak on 120 VAC RMS.

crb478 · 04-02-2018, 07:06 PM

I have a 1998 Beaver and all of my lights are 120 volt not 12 volt. I don't know if other RV's are wired this way or not, but I have tested the out put of all of them and they are a full 120 volts, some on 3 way switches some with dimmers.