DIY Home Improvement, Remodeling & Repair Forum

DIY Home Improvement, Remodeling & Repair Forum (http://www.houserepairtalk.com/forum.php)
-   Electrical and Wiring (http://www.houserepairtalk.com/f9/)
-   -   Range wiring (http://www.houserepairtalk.com/f9/range-wiring-8142/)

Texas 12-11-2009 04:54 PM

Range wiring
 
I am looking at the supply to the stove/range (typical stovetop with broiler/oven below) in this old house and want to make sure they did it properly.

I see a #10 ground, two #6 hots, and a #10 neutral, off a double pole 50A breaker. All wires copper, run <50'.
Did they do it correctly?
Thank you.

Nestor_Kelebay 12-11-2009 06:21 PM

Can't say about the wire size, but I'll tell you all what I knows for sure...

The 50 amp breakers is right. Electric ranges come in at least two standard sizes; 30 inch wide for normal residential stoves, and 24 inches wide for "apartment" size stoves. The bigger ranges will have two 8 inch surface elements (instead of only one) and larger bake and broil elements, and will typically require 50 amp service. That means 50 amp fuses on BOTH the black and red wires going to the range. Because there's no designated plug and receptacle configuration for 40 amp, 220 volt service, the smaller apartment size ranges will still use the same cord and plug as the large residential 50 amp ranges, but will typically be fused down to 40 amp service by using two 40 amp fuses or breakers instead of two 50 amp fuses or breakers.

(Electric clothes dryers will typically have two 30 amp fuses and will use a different plug and receptacle configuration designated for 30 amp 220 volt service so that you can't plug a dryer cord into a stove receptacle or vice versa.)

There's a convention in wiring terminal blocks, plugs and receptacles for 220 volt appliances, and that convention is that the three connection points will alway be in a straight line. The white neutral wire will ALWAYS be connected to the MIDDLE connection point, and the two hot wires (black and red) will be connected on either side of the white wire. It doesn't matter which side the black and red are on, so long as white is in the middle and black and red are on either side, you're good. That's true even if you have red connected to black on opposite sides of a terminal block, or if the stove's red wire connects to the prong of the plug that goes into the slot of the receptacle that the house's black wire is connected to. As long as white's in the middle and the black and red hot wires are on either side in both the plug and receptacle or on both sides of the terminal block, then it's kosher and your karma is in harmony with the universe.

The fourth connection terminal for ground won't be in the same line (cuz that could cause confusion) and will always be easy to recognize cuz it'll be permanently electrically connected to ground and/or the steel electrical box the receptacle is mounted in.

Dunno if this helps any. Hopefully an electrician in here can confirm that the wire sizes are OK.

rdmayers 12-12-2009 08:15 AM

The wire size is correct for a 50 amp circuit,#6 is rated for 60 amps,but what i do not understand is you say the neutral is a #10. In a normal cable all the conductors are the same size except for the ground which would be #10.

Nestor_Kelebay 12-12-2009 10:49 AM

Rdmayers:

It's cuz the black and red wires both carry the same voltage, but they're out of phase by 180 degrees. As a result, the current and voltage of both the black and red wires (ideally) would cancel each other out perfectly where they meet at the white wire. So in a perfect world, the current and voltage in the white neutral wire should theoretically both be zero. How big a wire do you need to carry 0 amps at 0 volts?

But, the real world isn't perfect and Lassie kills chickens. You'd get close to complete cancellation of the voltage and current in a stove ONLY because the heating elements in it act like almost perfect resistors. They have almost no reactance.

It's when you put the black and red wires through reactive loads like capacitors (TV sets and CRT computer monitors) or inductive loads (like electric motors and electromagnets) that the current sine waves get out of phase with the applied voltage sine waves. And, when you have the current and voltage sine waves in both the black and red wires out of sync, when they meet at the white wire they won't cancel out completely, and you can have some residual current and voltage in the white wire.

I'm certainly no expert on this stuff, and I don't want to give that impression. Hopefully, one of the electricians in here can explain reactive loads better than I did. But, rest assured, in a resistive load like a toaster, light bulb or kitchen stove, both the voltage and current from the black and red wires will almost completely cancel out where they meet at the white wire, so there won't be nearly as much current or voltage in the white wire as there is in the black or red wires, and so you don't need nearly as big a white wire to carry that small amount of voltage or current.

I have a write-up on my computer hard drive that explains house wiring a bit better. I wrote it up for a lady that wanted to know how to install a cord and receptacle on her dryer so that she could clean under and behind it easier. If anybody wants, I can post it here. It explains about the phase difference between the red and black hot wires in 220 volt wiring and why the voltage and current in the white wire isn't always zero.

rdmayers 12-12-2009 01:17 PM

I guess you did not understand what i was saying. Normally all the conductors in a cable are the same size. they do not under size the neutral. So the question i am asking is how there is only a #10 neutral. I understand exactly how everything works.and i also understand that they do not under size the conductors in a cable. I am not questioning if the conductor will carry the load, the only thing the neutral is used for in a electric range is the timer and light. I am just asking how the #10 neutral got there.

travelover 12-12-2009 02:32 PM

I think the neutral is there for the 110 volt applications of the range (like the light, timer, etc). As Nestor so succinctly pointed out, the 220 volt current flow is all through the red and black wire. And the ground wire is just that - a ground wire.

Nestor_Kelebay 12-12-2009 03:05 PM

Quote:

Originally Posted by rdmayers (Post 37652)
Normally all the conductors in a cable are the same size. they do not under size the neutral. So the question i am asking is how there is only a #10 neutral.

Yes, you are right. Now that I come to think of it, every range and dryer cord I've ever installed had a white neutral wire of the same gauge as the red and black wires, even though it would appear that it didn't need to be as big.

We need an electrician in here to tell us whether the reason the neutral is the same size just because of electrical code requirements. It's a guess, but I'm guessing the electrical code requires the neutral to be of the same size in the event of a short circuit. If the neutral were required to carry the same current as the black or red if the range shorted out, then undersizing the neutral could result in a fire.

rdmayers 12-12-2009 03:07 PM

Nobody seems to understand what i am asking. I would like to find out how a #10 neutral got to the range location. I know what the neutral does once it get there. What I am saying is they do not make a romex with 2 #6 and a #10 neutral and a #10 ground. So I just wanted to know how the neutral ended up being a #10. Did they run conduit to the range location and pulled the conductors in it, or did they run a 6-2 with ground an ran a single conductor #10 for the neutral,which would be against code. So for the third time, how is the #10 neutral getting there. That's what i want to find out.
Texas asked the question if it was done correctly.I can not answer this until i find out how the #10 neutral gets there.Is this so had to understand.Everyone want to reply,but nobody want to answer my question

Nestor_Kelebay 12-12-2009 04:00 PM

RDMayers:
Quote:

Everyone want to reply,but nobody want to answer my question
That's cuz only Texas can answer that question.

Texas: Can you describe the wiring between your electrical panel and your range please.

Blue Jay 12-12-2009 04:00 PM

Quote:

Originally Posted by rdmayers (Post 37660)
Nobody seems to understand what i am asking. I would like to find out how a #10 neutral got to the range location. I know what the neutral does once it get there. What I am saying is they do not make a romex with 2 #6 and a #10 neutral and a #10 ground. So I just wanted to know how the neutral ended up being a #10. Did they run conduit to the range location and pulled the conductors in it, or did they run a 6-2 with ground an ran a single conductor #10 for the neutral,which would be against code. So for the third time, how is the #10 neutral getting there. That's what i want to find out.
Texas asked the question if it was done correctly.I can not answer this until i find out how the #10 neutral gets there.Is this so had to understand.Everyone want to reply,but nobody want to answer my question

Can't tell you in this case, I know I have seen older wire with a smaller neutral but they did NOT have the ground wire.


All times are GMT -6. The time now is 06:51 PM.