Friends home 220 power safe ?

[traveldawg]

It only sounds complicated......

If you are handy with a multimeter you can measure his outlet to see how it is wired. Actually - since no one really knows what was done for the welder this is pretty much a MUST MEASURE situation.

If you are not handy or cannot measure the outlet yoiu probably want to pass on the offer.

FIRST - it has to be a 14-50R receptacle that matches your 50amp plug. If it isn't them move on......

IF it is the right receptacle (a 14-50R just like the one in a campground) you should measure the voltages to determine if you will be safe.....

In this diagram it show how it should be measured. You want to CONFIRM:
W to X = 120 VAC
W to Y = 120VAC
X to Y = 220 (actually should be 240VAC
W to G = 0VAC (or very close to it)



Finally - this would be a good time to install a power protection device similar to this.

[xrated]

Its just two 110V 50A (2 phase) lines, a neutral and a ground wire.

Attachment 39261

There is no such thing as (2 phase). It is exactly like the power that feeds into your home.....240V Split Phase.

[jkwilson]

Going to spend a week at a friend's house and he says he has power for me. He added a 220 line to run a welder and says i can use the for our 5th wheel (50 amp rig) He doesn't recall the type of plug off hand but will send me a pic. I'm wondering if that would be the same power as the 50 amp pedestals in RV parks and safe to use. I seam to recall its "Not"
Thanks

Not usually. Most welders use a straight 240V circuit with a 3 pin plug, while your RV requires a 120/240V circuit with a 4 pin plug. The 4th pin is critical to safely operating the 120V circuits in your RV. Damage will occur to things inside your RV if you connect to straight 240V power, even though it may work at first while lightly loaded. Once you turn on an AC, electric space heater, hair dryer, electric water heater, etc., the voltage inside the RV will jump to close to 240V and things will smoke.

It’s not unusual for an electrician to pull a neutral wire on such an installation, but it might be taped up in the box. You’d need an electrician to convert it even if the wire is there.

[Corky2]

There is no such thing as (2 phase). It is exactly like the power that feeds into your home.....240V Split Phase.

Yes, two phase and three phase are a thing and very common. Two phase and split phase means the same thing.

[xrated]

Yes, two phase and three phase are a thing and very common. Two phase and split phase means the same thing.

Uhh Nope! There are people that call split phase "two phase", but it's not what it actually is. The power transformer has one winding on the secondary side of it. At the electrical center of that winding is a tap, which is your neutral leg and it "splits" the one winding into two electrical legs that are 180° out of phase with respect to each other. Split phase is the correct terminology.

And I'm very familiar with three phase power, having been a Journeyman Electrician for over 41 years.

[dryfly]

I second the recommendation of the Progressive Industries HW50C Hardwired EMS Surge & Electrical Protection, or another EMS of your choice. I never gave an EMS a thought when I had trailers wired for 30 amp service. With 50 amp service there are so many issues that can arise plus high or low voltages in a campground. I've had mine trip and discontinue electrical service because of low voltage, which can be very detrimental to appliances. However, even with an EMS I would want to know exactly the wiring configuration I was plugging into.

[Jerryr]

NO. NO. NO. You can cause damage to every AC device in your RV if you try to connect to a typical welder receptacle.

Welders typically use a 6-50R 240v receptacle. It does not have a neutral which is necessary to provide the proper power to a 50 amp RV. A 14-50R 120v/240v RV receptacle to provide 2-120v legs. The RV does not utilize 240v anywhere in the RV.

[Corky2]

Uhh Nope! There are people that call split phase "two phase", but it's not what it actually is. The power transformer has one winding on the secondary side of it. At the electrical center of that winding is a tap, which is your neutral leg and it "splits" the one winding into two electrical legs that are 180° out of phase with respect to each other. Split phase is the correct terminology.

And I'm very familiar with three phase power, having been a Journeyman Electrician for over 41 years.

So your saying when someone says "2 phase" they really mean "split phase" because "split phase" is the correct terminology.

Got it!

[xrated]

So your saying when someone says "2 phase" they really mean "split phase" because "split phase" is the correct terminology.

Got it!

That's correct!

[jkwilson]

So your saying when someone says "2 phase" they really mean "split phase" because "split phase" is the correct terminology.

Got it!

You’ll generally hear engineers say two phase or referencing the phases, because when you work on signal and control applications there are many occasions when multiple phases are created in similar ways by tapping a transformer at different points. With North American power, the term phase has a very slightly different meaning. Our residential power is 240V single phase. In order to have lower voltage available for light duty, a neutral is attached to the center of the secondary of the transformer, creating two available 120V legs that are 180 degrees out of phase with each other from the single phase power source. From a non-power systems engineering perspective, you immediately think of these as different phases, but when dealing with power distribution it is a single phase.