Is my motorhome wired for 220 volts?

eddie haas · 09-15-2023, 01:23 PM

my coach has a 50 amp plug. is this for 220 volts?

IOS 3 · 09-15-2023, 02:28 PM

No. Absolutely not.

powercat_ras · 09-15-2023, 03:05 PM

Well, actually yes and no. The 50 amp outlet you plug into is on a 50A 240 volt 2 phase breaker. It is called a NEMA 14-50R and supports either 120 volt or 240 volt loads.

That said, nothing in your RV uses 240 volts. Only 120. Your RV uses each of the 2 "hot" wires for 120 volt breakers that return the power to a third wire called "neutral".

Other things that use only 240 volts (electric vehicle charger) or both 120 or 240 volts (elctric range or cooktop) can be plugged into the same outlet wired the same way to the breaker boc.

Some VERY high end RVs actually have power boxes that can take 240 volt breakers and can have a few things that use 240 volts subjects to the 50 amp total load on each leg limitation of the NEMA 14-50R.

Hope that helps.

bigb · 09-15-2023, 03:25 PM

I will add for the OP if you are considering plugging into a 240 volt car charger outlet, Air cond or power tool outlet, or considering changing a 240 volt outlet to a 14-50, it should be noted that 240 volt EV chargers, 240 volt AC units and power tools do not require a neutral and there is a chance that the EV outlet could be wired without a neutral. A power tool outlet and AC outlet is almost always wired without a neutral. Plugging into or converting such an outlet would cause damage to your RV.

In other words, you cannot plug into a 240 volt outlet, only a properly wired 240/120 outlet (4 wires).

Most of us use an EMS to check power before plugging in anywhere. You could get by with a meter but the EMS will protect you against a multitude of issues.

powercat_ras · 09-15-2023, 03:55 PM

If someone wires a NEMA 14-50R without a neutral, they have violated its installation requirements and electrical codes for that particular receptacle. Could it happen? Yes. Is it a legal receptacle install? No.

Unfortunately outlets get miswired occasionally, in particular NEMA TT-30R 30 amp 120V receptacles sometimes get confused with 240V 30 amp receptacles and get mis-wired with 240V which is catastrophic to RVs and TTs without a EMS with overvoltage protection that get plugged into the miswired receptacle

Personally I've never seen a NEMA 14-50R installed without the required neutral but I suppose some non-qualified person installing a electric vehicle charging receptacle could do a stupid thing like this.

You can buy a 50 amp outlet tester that will warn you of a missing neutral or ground on it. Don't plug your RV/TT into it UNTIL you see no fault lights on it as it only tests for problems and does not PREVENT those problems from reaching what gets plugged in to them.

For more money you can buy a PROTECTOR that will prevent the problem from reaching the RV or TT, such as the Power Watchdog PWD50-EPO-H, Bluetooth Surge Protector with Auto Shutoff, 50 Amp, a hard-wired one. Or there are others that go in-line between the end of the power cord plug and the power receptacle.

If it costs less than $ 250 its not a overvoltage / missing neutral PROTECTOR only a monitor with surge protection, so buyer beware. You get what you pay for.

**creativepart** · 09-15-2023, 05:51 PM

Quote:

Originally Posted by eddie haas

my coach has a 50 amp plug. is this for 220 volts?

Please tell us what your motorhome is... Year, Model and Floor Plan. You've not mentioned, nor did you enter that info into your Profile.

bigb · 09-15-2023, 05:51 PM

Quote:

Originally Posted by powercat_ras

Personally I've never seen a NEMA 14-50R installed without the required neutral but I suppose some non-qualified person installing a electric vehicle charging receptacle could do a stupid thing like this.

I have seen them, and I have read about people doing it when they wire up their own EV. I have seen 240 volt circuits re-purposed for EV's using a 14-50, Teslas and other EVs come with a 14-50P although you can get the proper adapters to fit a 6-50R the DIY isn't thinking about that, he is just going to wire up the recep that fits his plug. A Tesla HPWC is wired for 240 only, when that owner moves and takes the HPWC with him the next guy wires up a 14-50 for his Leaf.
I've seen plenty of DIT TT-30s wired for 240V also.

Over the years working in the field I learned never assume it is what you think it is. Thus my warning to the OP lest they assume.

Ray,IN · 09-15-2023, 08:07 PM

The difference is in your 50A (actually 100A) main entrance panel in the RV. Unless an RV is built with 240VAC appliances the special main panel has totally separate bus bars inside. Those bus bars are designed so a double-breaker cannot contact both.
Up to the RV main entrance panel, there is 240VAC.
The few high-end luxury MH's wired for 240VAC have a standard household main breaker panel installed that utilizes that service for 240V clothes dryers ,etc.

The standard 4-wire 240VAC clothes dryer receptacle is no different than the CG 50A pedestal receptacle. IT MUST BE A 4-WIRE DROP!
reference: https://www.myrv.us/electric/

thunderjet · 09-20-2023, 06:55 PM

When i had to replace my water heater element it was 120/1500 watt, I up graded to 240/ 4000 watt Element.
I had to add a 240/ 20 amp breaker to the fuse panel. and I also added a 3 way light switch to feed the heater. This gives me 1000 watts when on 120 volt ie on a 30 amp plug or genny and 4000 watts when on 50 amp plug.

The neutral wire from heater goes to black screw on the three way switch and the panel supplies a neutral or 2nd 120 leg to the other screws as needed

I found this to be a good use of 240 volt power. We take back to back showers with no problem when on 240 volt of course water at our Florida site is supplied at almost 60 degs
from the tower.

TJ

Ray,IN · 09-20-2023, 07:10 PM

Quote:

Originally Posted by thunderjet

When i had to replace my water heater element it was 120/1500 watt, I up graded to 240/ 4000 watt Element.
I had to add a 240/ 20 amp breaker to the fuse panel. and I also added a 3 way light switch to feed the heater. This gives me 1000 watts when on 120 volt ie on a 30 amp plug or genny and 4000 watts when on 50 amp plug.

The neutral wire from heater goes to black screw on the three way switch and the panel supplies a neutral or 2nd 120 leg to the other screws as needed

I found this to be a good use of 240 volt power. We take back to back showers with no problem when on 240 volt of course water at our Florida site is supplied at almost 60 degs
from the tower.

TJ

You lucked-out by having a main panel with alternating bus bars, normally they are straight on each side.