Expert: Master Bob - 2/11/2005

Question
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Followup To
Thanks Master Bob for your quick reply, I looked at the outlet and it is NEMA 10-50R. and goes to a 50 amp fuse.
The welder plug is a NEMA 6-50P the input data card on the welder says:
230 volts AC 48amps
60HZ single Phase
Thanks for all the help, and as far as the snow shoveling,,,, i sincerly symphathize with you, although i now live in Arizona, i was raised in Up-state new york and lived in Alaska for 6 years.  I've cursed many a snow plow drivers for filling in my driveway just as i finished cleaning it out. but i do miss it!
Mark

Question -
I have an existing 220v outlet, i have a small 22v welder.  the plugs are diffrent!  I took the cover plate off the outlet, and it has a red,black, and white wires, with a smaller bare ground wire connected to the outlet frame,  my welder however has only a white, black, and green wire, what do i do to the outlet to change it to fit the welder,, what do i do with the red wire?
thanks
Mark
Answer -
Hi Mark,

  Just getting back in....we are having a bad storm here in the Northeast...getting buried.

 There are several different possible plug and receptacle outlet configurations for 240 volt use....and the main difference is either twistlock versus non-twistlock, grounding versus non-grounding....and amperage size.

 Based on your description....your existing 240 volt outlet is a 120/240 volt configuration....having 2 hots, 1 neutral and a ground. (such as a typical dryer outlet has..)

 Your welder appears to requires no neutral....having just 2 hots and a ground (the black and white are hots...although white is normally used for neutral....just not on most welders)

 Looking at your info....it sounds like you are describing your existing outlet as a NEMA 14-30R or a 10-30R...depending on how the ground is. Your welder may have only a 6-20R or a 6-30R.

 I'll need you to review the different NEMA configurations and tell me which one matches up exactly to your existing outlet and which one matches the welder cord's plug end. For the chart showing all the different styles, please see:

http://www.leviton.com/sections/techsupp/nema.htm

 Please follow-up with the Code numbers for what you have...at both ends....and I'll try to help you get the correct connections...provided this welder uses the same amperage as the existing outlet supplies. (for example...if it's a 20 amp welder....and you have a 30 amp outlet...you will NOT be able to use this outlet to supply power for the welder..without changing the breaker and wire). The welder should have a metal nameplate on it stating how many amps it draws...

 Please follow-up with the requested Code numbers for the ends....and I'll do what I can to help out.

  Heading back out to clear the driveway....for the 3rd time today.

Best Wishes,

Bob Osgood
Master Electrician

RKO ELECTRIC


wwww.rkoelectric.com


rkoelectric@verizon.net  

Answer
Hi Mark,

  Sorry this response wasn't as quick as my earlier response...but with your experience in up state NY and Alaska..you already know what a crippling effect a storm like this can have......we got a non-stop 2 day total of over 22 inches..(waiting for the offical report - should be close to the 2 foot mark) ...mostly the wet heavy sticky stuff at that...closed just about every business in the area....what a disaster.  Maine is no stranger to significant amounts of snow....but the plows simply couldn't keep up....10 minutes later you couldn't even tell where they had just plowed. Top that off with tree branches breaking under the weight of the wet snow....and you've got power lines and communication lines down everywhere. We had several brief outages here yesterday...both with our DSL and power.

 Fortunately...it's over now (finally!)...and we have a sunny mid-30's day forecasted for today and tomorrow(the "calm after the storm" effect)...with rain coming early next week...to help wash some of this white stuff away. Lot's of clean-up to do...

  Okay...so your outlet is NEMA 10-50R and the welder plug is a NEMA 6-50P ...so your all set amperage wise. The problem becomes your outlet is a 120/240 volt - having 2 hots and a neutral (with a micro-ground to the frame)....and the welder is straight 240....having 2 hots and a ground...with no neutral.

 If you plan to no longer use the outlet for it's original use...with the fuse pulled (confirm power is off at the outlet) - you will need to change it over from a 10-50R to a 6-50R to match your welder plug....using the red and black as the 2 hots....and the white as the ground (tape the end of the white green at both ends)....and the small ground wire can be clipped off. (You'll note the neutrals and ground are connected to the same bar back at the main panel...so this is a legal change-over - as long as the white is made green)

  Connecting as above should provide you with the correct outlet and power for your welder.

 If it doesn't...or you run into any problems, please follow-up.

Best Wishes,

Bob - buried in Bangor, Maine