250volt/50Amp conversion to standard 220?

Hi Folks!
I have a question about household wiring. My father, in his infinite and gifted wisdom, installed a 250 volt 50 amp circuit for an arc welder in his shop. I recently inherited the family home but I have no intention in keeping the outlet or workshop as is. After much discussion we'd like to convert the circuit to a standard 220 outlet and use the room my father had as his shop area as a laundry room. My question is, What would need to happen to change the circuit and outlet to a standard household 220 volt wall receptacle? Can we just use some sort of adaptor or would we need to rewire the entire circuit? Would I need a Certified Electrician or can this be re-done with little hassle?

Looking at it , I'm not sure if it could be done. I need to be certain one way or the other.

Thanks in advance,
Too Wired

 

Standard single phase residential circuit is 240v not 220v. There are no standard 250v single phase or three phase circuits in the US.

 

Standard for what purpose? It is already standard for a welder. If you're referring to the voltage rating stamped on the receptacle, that is the maximum rating. The actual voltage is about 240V +/- 10%. Some people call this 220V, 230V, 240V, 250V but those are all the same type of circuit.

Since you mentioned laundry, I'm guessing you want a hookup for an electric cloths dryer. The existing circuit may be able to be converted, but probably not. The main issue is that welding circuits usually have only three wires and dryers require four wires. However your father may have installed a cable that has four wires and capped one of them off. If there is a conduit it may be as simple as pulling another wire through the conduit. If it is wired with a cable, the cable may need to be replaced.

Let us know what you want to do with this circuit and what wiring method is used. What is the breaker size, what are the wire sizes, and what color wires are installed?

 

I am thinking what might be confusing is the recept rating of 250V.

 

thanks for you're quick response! I mean standard for a 220 dryer outlet. Ok. guess I have some work ahead of me this week. If I were to turn off the main power to the house should I be able to take the receptacle and circuit breaker it's connected to apart and see how many wires it has? oh and what should I be looking for color-wise for the wires?

Thanks,
Rechlai

 

Your house is supplied with 240v ±5%. Modern dryers are designed to work in that range. You can safely open the receptacle by turning off the breaker but turning off the main breaker is even safer. To change the breaker you will need to turn off the main breaker. The receptacle box must contain 4 wires. One must be bare copper or green. One must be white. The other two are probably red or black but can be any color but white, gray, or green. If you have metal conduit continuous to the breaker box and is not old style BX you do not need the green or bare wire.

 

You should be looking for black, red, white and bare copper (or green) wires. You should also try to identify the wire size (AWG). The size needs to be #10 or larger (smaller numbers are larger wires).

To install the dryer, the breaker would be replaced with a 30A double-pole breaker. The receptacle would be replaced with a NEMA 14-30R and a matching 14-30P cord on the dryer. Follow the dryer's instruction manual to ensure the internal wiring is configured for a four-wire circuit.