Plug 50amp in to dryer outlet

[Dad]

http://www.myrv.us/Imgs/PDF/50-amp%20Service.pdf

Have a 2001 Monaco Dip. 50amp plug 4 prong. See above pdf. When I look at my dryer outlet it matches up to this pdf. We have used a volt meter to check for polarity. But every time I use the words "Dryer outlet" people in the RV world freak out. I have no idea my my dryer out let has the 4 wire plug, it is a new house so I guess that is what they are putting in.

So what is bad about using it to plug in when it match's up to this (how to install a 50amp guide)?

[jesilvas]

If the wiring, voltages, and amps match, it's fine.

Usually the issue with "dryer" or "welding" outlets is when you plug in 30A RVs.

[aauummm]

Originally Posted by Dad

http://www.myrv.us/Imgs/PDF/50-amp%20Service.pdf

Have a 2001 Monaco Dip. 50amp plug 4 prong. See above pdf. When I look at my dryer outlet it matches up to this pdf. We have used a volt meter to check for polarity. But every time I use the words "Dryer outlet" people in the RV world freak out. I have no idea my my dryer out let has the 4 wire plug, it is a new house so I guess that is what they are putting in.

So what is bad about using it to plug in when it match's up to this (how to install a 50amp guide)?

Whoa.....I'd wait for some of our electrical experts to chime in here before proceeding!

[Steve Ownby]

Originally Posted by Dad

http://www.myrv.us/Imgs/PDF/50-amp%20Service.pdf

Have a 2001 Monaco Dip. 50amp plug 4 prong. See above pdf. When I look at my dryer outlet it matches up to this pdf. We have used a volt meter to check for polarity. But every time I use the words "Dryer outlet" people in the RV world freak out. I have no idea my my dryer out let has the 4 wire plug, it is a new house so I guess that is what they are putting in.

So what is bad about using it to plug in when it match's up to this (how to install a 50amp guide)?

Older dryer outlets were 3 prong. The angled prongs were both hot and the round bottom prong was the neutral. The 30 amp RV outlet looks much like this old dryer outlet but is wired with one hot and one neutral with the bottom round prong a ground only. If the 4 prong outlet you are referring to measures as follows, it's ok to use:
1. 120 vac from each hot to neutral.
2. 120 vac from each hot to ground.
3. 240 vac from hot to hot.
4. Zero vac from neutral to ground.



Steve Ownby
Full time since '07

[paz]

Be very careful using any plug that was wired for use with a dryer. A 3-prong dryer plug looks a lot like the 3-prong, 30-amp plug on RVs. The problem is most dryers are 240V, and most dryer receptacles are wired accordingly. 240V will fry the electricals in your RV, and that's why everyone freaks out when you mention "dryer plug."

If your dryer plug indeed has 4 prongs, check it out according to Steve's description before trying to use it.

[andy29847]

The dryer plug is probably a NEMA 14-30R, the RV plug is probably a NEMA 14-50r - they are wired the same but the ends don't match.

[BatteryPro]

Originally Posted by paz

...240V will fry the electricals in your RV, and that's why everyone freaks out when you mention "dryer plug.”....

The only way you can “fry the electricals” is if someone has miswired the RV or the receptacle you plug into. All 50 amp RV plugs are 240 volt split phase. 240 volts does not harm your RV. In your AC breaker panel, the 240 volts is split into two discrete 120 volt circuits by using one hot leg and the neutral. Some all electric coaches use the 240 volts for cooktops.

Electric dryer plugs come in 4 styles. See photo. All are 240 volts. Some use 3-wire, some use 4-wire. One of the 4-wire plugs (top right) is identical to a RV 50 amp plug. That type of receptacle can be used safely.

The other 3 dryer plugs do not match any RV plug so there is no way to plug your RV into one of the other receptacles. If someone has modified your RV cord, all bets are off!

Larry

[wa8yxm]

The problem with everybody "Freaking out" is we are used to seeing folks wanting to plug a 30 amp RV into a welder or dryer outlet, Some of which are capable of accepting the plug, but alas, you should not do this, As it's dangerous and they will damage THEIR Rvs.. Please note I'm talking about THEM, not you.

In your case. Yes there may be a danger.. However I suspect odds are slight.

Just to be safe you shoudl trip the breakers (TURN OFF) feeding that outlet then inspect the wires.. Are the black, read,a nd white wires the same size? IF so no danger. If the white wire is smaller (possible but I do NOT think that is code) There is a fire hazard,, but so long as they are the same size. No problem.

The Green/bare wire can be smaller, also no problem.

[MattC]

Originally Posted by Dad

http://www.myrv.us/Imgs/PDF/50-amp%20Service.pdf

Have a 2001 Monaco Dip. 50amp plug 4 prong. See above pdf. When I look at my dryer outlet it matches up to this pdf. We have used a volt meter to check for polarity. But every time I use the words "Dryer outlet" people in the RV world freak out. I have no idea my my dryer out let has the 4 wire plug, it is a new house so I guess that is what they are putting in.

So what is bad about using it to plug in when it match's up to this (how to install a 50amp guide)?

You have checked the outlet, so I really don't understand the problem.

If the plug fits, Use it.... (If it is a 14-50, Three flat blades the same way and a round ground pin, that is what it is.)

I plug my coach into the "Welder" outlet according the panel. And, according to the USGC, I am an expert. I am a licensed ships engineer and was and industrial electrician at one time.

Matt

[CapuTech]

Originally Posted by BatteryPro

The only way you can “fry the electricals” is if someone has miswired the RV or the receptacle you plug into. All 50 amp RV plugs are 240 volt split phase. 240 volts does not harm your RV. In your AC breaker panel, the 240 volts is split into two discrete 120 volt circuits by using one hot leg and the neutral. Some all electric coaches use the 240 volts for cooktops.

Electric dryer plugs come in 4 styles. See photo. All are 240 volts. Some use 3-wire, some use 4-wire. One of the 4-wire plugs (top right) is identical to a RV 50 amp plug. That type of receptacle can be used safely.

The other 3 dryer plugs do not match any RV plug so there is no way to plug your RV into one of the other receptacles. If someone has modified your RV cord, all bets are off!

Larry

x2. Exactly right. Those freaking out don't know what they don't know (yet somehow have tremendous confidence in giving wrong advice). The pdf you linked explains it well.

I have three engineering degrees - one of which is in electrical engineering if that helps qualify the advice.

[cochise1949]

When we had an electrician install a 50amp outlet in our driveway, he saw that we had an unused dryer circuit, having gone to a gas dryer. Made his job easier (so he said) as well as the hit on my wallet. He split that 240v into 2 120v legs for the RV. Worked well.


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[70ChevelleSS]

Originally Posted by cochise1949

When we had an electrician install a 50amp outlet in our driveway, he saw that we had an unused dryer circuit, having gone to a gas dryer. Made his job easier (so he said) as well as the hit on my wallet. He split that 240v into 2 120v legs for the RV. Worked well.


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2 120v legs, 180* out of phase is 240v. Your dryer outlet was always 2 120v legs. He really didn't do anything but maybe replace the wire with longer wire and put the outlet on the end.

[wa8yxm]

I will say again, Those freaking out do not read well.

Many Dryer outlets are 3-wire 240 volt.. And many of them can accept a TT-30 plug.. You plug an RV into one of these, bad things happen.

We are very used to reading of those bad things when someone does just that..

But that is not the case in the Original Poster's post.

Still people fail to properly read that it is a modern FOUR WIRE outlet, not a 3 wire from the sixties and thus they freak out. I read (And several others here it seems) read the full post.. Still others did not,

Best advice: Plug in something like a Progressive Industries PT-50C or better yet put an HW-50C in your RV.. IF it approves.. you are generally good.

But as I said before I'd check the outlet to make sure the neutral is the same size as the hot wires.. Just to be safe.

[paz]

Originally Posted by BatteryPro

The only way you can “fry the electricals” is if someone has miswired the RV or the receptacle you plug into...
Larry

That's one of the points I was trying to make. OP stated his "dryer plug" matches the link in his post, which shows a 14-50R RV receptacle. If it was indeed being used for a dryer, it was very likely mis-wired.

The other point I was trying to make is the reason many people "freak out" when you mention a dryer receptacle is most people know dryer receptacles are usually wired for 240V. As you so aptly point out, however, even though the plugs look similar, they won't fit.