220v question

[Yossarian 208]

I know there are a couple of electricians on here so  I figured this would be a good place to ask. My wife is a potter (a pretty amazing one) and she just got a new kiln.  The plug doesn't match the receptacle, that should be an easy enough fix, but nothing with this house is ever straightforward.  This is a picture of the receptacle that is being replaced.  I believe that the red and black are the hot wires and the white is ground. Is that correct? 

[The Tuul Crib 7,336]

5 minutes ago, Yossarian said:

I know there are a couple of electricians on here so  I figured this would be a good place to ask. My wife is a potter (a pretty amazing one) and she just got a new kiln.  The plug doesn't match the receptacle, that should be an easy enough fix, but nothing with this house is ever straightforward.  This is a picture of the receptacle that is being replaced.  I believe that the red and black are the hot wires and the white is ground. Is that correct? 

Yes white and green are  common  

Or ground.  And a four prong is an added ground which doesn't make sense to me anyway but that is code here 

Edited September 8, 2019 by The Tool Crib

[953 nut 55,099]

You are showing us a 30 Amp dryer receptacle. What is the amperage draw on the new Kiln you are going to hook up? If it is greater than 30 amps you will need to have new wires installed that will handle the load. Just replacing a device could cause a fire, we don't want that.

[Yossarian 208]

Not sure of the draw on the kiln. She's had another kiln plugged into it for about five years now.  It was the outlet for a stove originally.

ETA: I think the 30amp your thinking of has an L shaped prong.

 

Edited September 8, 2019 by Yossarian
add info

[953 nut 55,099]

That wire is not heavy enough for a range.    Can you take a good picture of the information plate on the new kiln and post it please?

[Sparky-(Admin) 21,312]

  That solid copper wire is #10 gage max. You can put that on a 30amp breaker or fuse max. Code states you can only load up to 80% so your kiln needs to draw 24amps or less.

  

[Yossarian 208]

Here is the info from the kiln.  I pretty sure it's #8 wire in the the receptacle. When we switched out the stove for the kiln we were renting the house. The landlord went through everything and consulted electricians he worked with to make sure it would all work.  The kiln is rated for #8 wire some require  #6, this one was chosen because it is not. The receptacle is a 50amp and its on a 50 amp breaker.  When I can find my wire stripper/crimper I can measure the gauge to be sure. 

[ZXT 2,401]

Can you see anything on the sheathing? It should say but there probably isn't enough sticking out. Sheathing appears black, but that doesn't mean it's #8 for sure. I will say that I have never seen black-sheathed 10/3. 

 

Can you get us a picture of the plug on the kiln? That is a 50A receptacle that you have already, but there are a few different styles. 

 

Being that it's an older home (Which is apparent from the lack of a ground wire) it wouldn't surprise me if that were 10 AWG on a 50A breaker.. I see worse daily. Unrelated, but what brand breaker panel does the house have? Depending on the brand it might not make a difference what size breaker it's on...

Edited September 8, 2019 by ZXT

[Yossarian 208]

Home was built in '73 by Wick.  Square D box.  I should have included more info in the original post.  I'm not replacing the receptacle, I'm changing out the plug on the new kiln. The kiln tech said it wouldn't void the warranty as long as the plug is rated for 40 amps or more.  The issue is that the plug was wired differently on the old kiln. On the old one the white wire was attached to what I think was the ground (that should be the first picture).  The plug attached to the new kiln has the green in the center position (second and third picture). While I was at work my wife had switched the plugs and plugged in the kiln.The control panel was lit up and everything seemed to be functioning but it was not test fired.  Wanting to double check her work before a test fire, since she doesn't do that sort of stuff very often, I unplugged it and opened up the plug.  Copying the placement of the plug she had removed she  wired the rounded plug with the green in the center position.  It is very clearly marked W. Inside the cover it is clearly labeled "white".   I pulled the receptacle to verify which prong plugs into the ground/common and without the presence of a green or bare wire it went over my pay grade.  Some googling seemed to indicate that in a red,black, white configuration white was the neutral/ground and maybe on the old kiln they had wired it with black and green as hot.  The old kiln was fired successfully at least twice a month sometimes weekly for the last 5 years so I have no reason to believe the plug was wired wrong.   If the wiring in the house is seriously fubared I'll address that. I have a good friend that is a very experienced electrician but he's in Canada catching walleye right now. In the mean time I want to make sure the plug is attached correctly.

[Racinbob 11,045]

The very best thing you can do is have a qualified electrician check it out. I hate and am against troubleshooting some things over the internet, phone, etc. and electrical issues are at the top of that list. Keep in mind that electricity is colorblind. The neutral is a grounded CONDUCTOR. Yes, it connects in the panel in the same place as the ground but if you think it doesn't carry a load just try opening it up and hanging on to the two ends while in operation (NO, don't really try that!). That being said, I doubt that your kiln needs a neutral because it doesn't have any 110/120 volt loads like, say a range. That is the reason that a three wire cord is fine. Cords are usually undersize and exceptions in the code allow it. Keep in mind the size of that cord on a table lamp, TV, etc. and they are plugged into a circuit backed by a 15 or 20 amp breaker. That's one of the reasons I only use 15 amp breakers on all the general use receptacles in our house except for certain appliance outlets. I'd be tempted to use 10 amp breakers if they made them. I repeat, have a qualified electrician look at the owners manual and verify that your wiring is adequate and wired properly.

[953 nut 55,099]

6 hours ago, ZXT said:

Sheathing appears black, but that doesn't mean it's #8 for sure. I will say that I have never seen black-sheathed 8/3.

Can't go by the sheathing color of non-metallic cable on older installations. White 15, yellow 20, orange 30, black 45 amp started being done in the early part of this century.

57 minutes ago, Racinbob said:

very best thing you can do is have a qualified electrician check it out.

[bc.gold 3,403]

• The Chinese love to complicate things, this information is from the Skutt website. Your kiln uses a Nema 6=50 receptacle with number 8 wire.
•  
• Wires coming off the kiln black and white are hot and green is ground
•  

https://skutt.com/skutt-resources/resources-just-for-you/architectural-specifications/electrical-specifications/

KM-822

1

208V

38.5A

8000W

8

6-50

Edited September 8, 2019 by bcgold

[Racinbob 11,045]

There are exceptions allowing the white to be connected to one of the hot legs. This is one of them but remember what I said, electricity is color blind. I'll say it again, get a qualified electrician to check things out and verify you have a safe installation in all respects 

[bc.gold 3,403]

6 minutes ago, Racinbob said:

There are exceptions allowing the white to be connected to one of the hot legs. This is one of them but remember what I said, electricity is color blind. I'll say it again, get a qualified electrician to check things out and verify you have a safe installation in all respects 

 

I agree with ya, if connected with the wrong service he and his missus could end up standing on the street in their night cloths watching the house burn.

 

After the insurance guys discover the cause of the fire will void paying out on any claim.

[Yossarian 208]

Thanks guys. I guess I'm glad posted that.  Like I said, I've got an electrician friend that will look at it.

[Matt Young 63]

Dvom is your friend to see how the house plug is wired. Done a lot with generation over the years

[ZXT 2,401]

11 hours ago, 953 nut said:

Can't go by the sheathing color of non-metallic cable on older installations. White 15, yellow 20, orange 30, black 45 amp started being done in the early part of this century.

Yep, I know the colors. Started being color coded around 2001. I pull a couple thousand feet of Romex almost daily. I did mean to say 10/3 rather than 8/3 in my first post though. 

 

Yossarian, If you can verify that you have 8/3 and own a DVOM to ensure that power is in fact off, you should be perfectly capable of changing the receptacle yourself. That being said, if you friend charges reasonably, then by all means have him do it. 

 

Racinbob, if the white were being used as a hot leg it would be connected to a different terminal in the receptacle. It should also be marked with black tape in the panel.

[adsm08 2,032]

Do not lick 220V.

 

That's all I really know about house wiring. Now if we want to talk about 12V, then I know things.

[Yossarian 208]

32 minutes ago, ZXT said:

 

 

Yossarian, If you can verify that you have 8/3 and own a DVOM to ensure that power is in fact off, you should be perfectly capable of changing the receptacle yourself. That being said, if you friend charges reasonably, then by all means have him do it. 

 

 

The plan is to just change out the plug. If I end up needing to pull new wire I will go with whatever my buddy says as far as receptacle.  It might cost me a cold beer and a few hours of fishing my lake. 

 

all of this fuss will lead to more stuff like this

[Racinbob 11,045]

1 hour ago, ZXT said:

Yep, I know the colors. Started being color coded around 2001. I pull a couple thousand feet of Romex almost daily. I did mean to say 10/3 rather than 8/3 in my first post though. 

 

Yossarian, If you can verify that you have 8/3 and own a DVOM to ensure that power is in fact off, you should be perfectly capable of changing the receptacle yourself. That being said, if you friend charges reasonably, then by all means have him do it. 

 

Racinbob, if the white were being used as a hot leg it would be connected to a different terminal in the receptacle. It should also be marked with black tape in the panel.

Depends which picture you're looking at. All the more reason to have a qualified electrician look at it.  

[ZXT 2,401]

4 hours ago, Racinbob said:

Depends which picture you're looking at. All the more reason to have a qualified electrician look at it.  

Whoops! I apparently looked right past that post with all of the pictures. Thanks for pointing that out! 

 

Yes, let your electrician friend look at it. The plug you have a picture of with the "W" on it is definitely wired wrong. Ignore that label. What you are installing is a 50a non-grounding style range plug, which would've had a white wire present for the neutral, since a neutral is not supposed to be bare copper. The factory plug on the new kiln uses a 50a grounded (often used on welders and such) receptacle, which doesn't require a neutral, so the labeling will be incorrect.  Chances are if you had fired it up and touched it while grounded (e.g. walking around with your shoes off), you would've been shocked. It needs to be wired identical to how the original plug on the new kiln (picture 2) was wired. In other words, you need to swap the white and green in picture 1. 

 

Good to hear that it has a Square D box. Square D QO is just about the best out there. Glad you don't have a Federal Pacific or Zinsco. Those were extremely common around that time and will burn your house down if you do something wrong. They don't trip.

 

By the way, those are some great looking pieces your wife made! Does she just do it as a hobby or does she sell those?

Edited September 9, 2019 by ZXT

[Yossarian 208]

25 minutes ago, ZXT said:

Whoops! I apparently looked right past that post with all of the pictures. Thanks for pointing that out! 

 

Yes, let your electrician friend look at it. The plug you have a picture of with the "W" on it is definitely wired wrong. Ignore that label. What you are installing is a 50a non-grounding style range plug, which would've had a white wire present for the neutral, since a neutral is not supposed to be bare copper. The plug on the new kiln uses a 50a grounded (often used on welders and such) receptacle, which doesn't require a neutral, so the labeling will be incorrect.  Chances are if you had fired it up and touched it while grounded (e.g. walking around with your shoes off), you would've been shocked. It needs to be wired identical to how the original plug on the new kiln (picture 2) was wired. In other words, you need to swap the white and green in picture 1. 

 

Good to hear that it has a Square D box. Square D QO is just about the best out there. Glad you don't have a Federal Pacific or Zinsco. Those were extremely common around that time and will burn your house down if you do something wrong. They don't trip.

 

By the way, those are some great looking pieces your wife made! Does she just do it as a hobby or does she sell those?

 

Thank you. That is what I have figured out so far.  I believe the plug with the W was wired "correctly" for the kiln it was on. That is the connections were all correct even if the colors weren't.  It was not the factory cord or plug but it worked faithfully for 5+ years.  Swapping white and green seemed to be the correct course of action. Thanks everyone here for confirming that.  The sub-standard wiring in the wall is another issue entirely that I hadn't expected, will take care of it. Like I said, nothing in this house is straight forward.  Best part is, I bought it from the original owner.

 

She is a full time art teacher but she puts in easily 20+ hrs a week for her business.  Much more over the summer. She sells on Etsy under 3Dandelion seeds and does local craft fairs and Renaissance Faires. 

[Seathe 0]

I am not an electrician, however as I know the red and black wires must be the hot ones.

[seven 202]

You really have to have #8 wire pulled put on a 2 pole 50amp breaker 8/2 Romex two hots  black and white one equipment ground bare.

[Yossarian 208]

I'm not sure exactly how this thread made it back into rotation 2 years later, but I'll respond for those that need closure.  I did have my electrician friend come out and look at the kiln, the receptacle, the breaker box and everything in between.  He knew the original owner of the home and was not surprised by the situation. Although, he was slightly amazed that the house hadn't burned down just from the use of the stove that previously occupied that outlet.  I bought exactly what he told me to buy and it was installed exactly as directed.