Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

Installing an oven in a house built in '78 - Do I replace the entire feed?

Installing an oven in a house built in '78 - Do I replace the entire feed?

Reply

  #1  
Old 10-16-13, 09:18 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
Installing an oven in a house built in '78 - Do I replace the entire feed?

The original oven died (35 years old). I have a main feed coming from the 50 amp breaker (Red, Black and a paper "insulated" white ground). The feed from the breaker is a heavier gauge then it's reduced (in a box) to 10# and wired directly to the old oven. The reduced feed has an actual insulated white copper ground and an bare copper line (both from the paper insulated copper ground of the main feed). When I stripped the reduced black and red wires I noticed they are are twisted wire (aluminum?).

I have a newer oven (2009) with a 3 way plug. The plug on the new oven says 50 amp and the back of the oven says "Use a new UL listed 40 amp power supply cord, 8 gauge copper or 6 gauge aluminum". I'm not sure if those specs refer to the outlet or the actual cord already attached.

I bought a 50 Amp 3-Pole,3-Wire non-grounding outlet. Am I going to burn my house down if I use the existing wiring? Should I replace all the wiring back to the breaker?

I have pics if anyone needs me to upload them I would be greatly appreciative if anyone has some feedback for me.

Thanks in advance!
 
Sponsored Links
  #2  
Old 10-16-13, 10:03 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: NJ - USA
Posts: 43,439
Welcome to the forums.

An aluminum feed to the appliance is not necessarily a bad thing if the wire is sized large enough and you use a receptacle that is designated for Cu/Al use.

Can you describe the type of wire that is run... is there anything on the outer jacket ?
 
  #3  
Old 10-16-13, 10:12 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
PJmax,

From the pic I have it shows the aluminum wire outer jacket to read "XPT #10 AWG (UL)" which I would think is too small if those specs on the back of the oven (8 gauge aluminum) are indeed for the outlet.
 
  #4  
Old 10-16-13, 10:45 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,354
We need the info from the cable in the wall, not the oven wiring.
 
  #5  
Old 10-16-13, 11:00 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
pcboss,

Thank you both for the replies. I don't have the exact information from the sheath of the cable in the wall but here is a pic. It's much larger in gauge than the #10 going to the old oven. The white copper cable is paper insulated. I did check that.

I won't be able to get you the info from the sheath of that main cable until I get home though.
 
Attached Images  
  #6  
Old 10-16-13, 11:47 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,354
If you can't see the info on the cable near the oven, look near your electric panel.
 
  #7  
Old 10-16-13, 11:51 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
PCboss,

The only electrical panel is the breaker box in the garage. It's on a double 50 amp breaker. Not sure if that means it's 100 amps? Attached is a pic.
 
Attached Images  
  #8  
Old 10-16-13, 06:44 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: NJ - USA
Posts: 43,439
That looks to be older style 8-2 NM type cable with a #10 or #12 ground. So there doesn't appear to be any issue with aluminum wiring. That wiring is all copper. Even the twisted wires. They may be tin plated and look like aluminum. That wiring should be fine.

Sometimes if the cable jacket is painted at one end it's not at the other end. PCboss was suggesting to look at the jacket of the wire at the panel end. If the panel is in the wall that could be a little tough. That is a two pole 50A breaker. It is 50amps at 240 volts. The handles don't get added together.
 
  #9  
Old 10-17-13, 05:48 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
PJMax,

Thanks for the reply as well. I inspected the twisted wire and I did see copper color within it where I had snipped it. Never knew it was plated.

Okay so I guess the next question since the wiring appears to be okay is when they wired the original oven there are 4 wires coming from the 3 wire. Red,Black,White,Unshielded Copper (ground?).

White-> Reduced Gauge Red
Black-> Reduced Gauge Black
White Paper-->White and Unshielded Copper


Since I purchased a three way, three pole, non ground 50 amp outlet I'd assume I need to remove the bare copper line from that feed and just wire up the Red,Black,White wires correct?
 

Last edited by avanbaelen; 10-17-13 at 06:07 AM.
  #10  
Old 10-17-13, 06:28 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,643
If it is #8 as PJ thinks you must use a 40 amp breaker. Go to the hardware store and buy one foot od #8 and #6 stranded THHN/THWN. Compare them with insulation removed to the wires you have to determine size. However best practice is to replace with 3 conductor plus ground cable sized to the amp requirement of your new oven.
 

Last edited by ray2047; 10-17-13 at 11:11 AM.
  #11  
Old 10-17-13, 10:53 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,212
However best practice is to replace with 3 conductor plus ground cable sized to the amp requirement of your new oven.
This is not only the best practice, but a requirement. The old 8-2 W/G NM cable (aka romex) cannot be used if your oven requires a neutral conductor and evidently it does. The bare ground in NM cable HAS NEVER been approved to be used as a neutral conductor.
 

Last edited by ray2047; 10-17-13 at 11:12 AM. Reason: Typo in quote from my post.
  #12  
Old 10-17-13, 11:02 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
CasualJoe,


Yeah the copper ground in that bundle has a white paper like "insulation. It's not the same as the other two larger wires (which appear to have wire insulation similar to current wire). As ray mentioned also I'll need to change the breaker too. Guess I'll run entirely new cable and a new breaker. Rather do things the right way than burn my house (and myself) up.
 
  #13  
Old 10-17-13, 11:35 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,212
In your post #7 you gave us a picture of your Federal Pacific Electric service panel. Just so you are aware, replacement of that FPE panel needs to be one of your next projects with high priority. Read some of this info on FPE.

The Federal Pacific Electric FPE Stab-LokŪ Panel Circuit Breaker Hazard, Repairs, Electrical Panel Replacement Electricians Directory for Stab-LokŪ Repairs

As ray mentioned also I'll need to change the breaker too.
Expect a new 2 pole 40 amp breaker to run between $40 and $50, depending on where you find it. FPE has been gone for a long time, but there are a couple manufacturers who still make them.
 
  #14  
Old 10-17-13, 12:21 PM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
Hmmm.... I figured I'd have to replace the electrical stuff if/when I bought this house but I didn't really know if that was just an overly cautious stance or not. Now I can say with confidence it's something I definitely need to do.

I assume a project of replacing all the electrical wiring/panels/outlets in the house would legally require a certified electrical contractor with an inspection by a local agency?
 
  #15  
Old 10-17-13, 01:13 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,643
I assume a project of replacing all the electrical wiring/panels/outlets in the house would legally require a certified electrical contractor with an inspection by a local agency?
In Miami almost certainly. Out in the county two miles south of the alligator ranch maybe not. Ask you local code enforcement office.
 

Last edited by ray2047; 10-17-13 at 02:43 PM.
  #16  
Old 10-17-13, 01:18 PM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
Thanks Ray. I'm up in Palm Coast in central Florida and they are pretty by the book here so I'm sure it'll definitely have to be inspected. Gonna talk with a few contractors that I know.
 
  #17  
Old 10-17-13, 02:47 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,643
You need an electrician or an electrical contractor not a general contractor. There is one thread on the board right now where the member is having to correct the electrical work by a GC. To get the panel changed out you just need a master electrician.
 
  #18  
Old 10-17-13, 03:01 PM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
Yes I figured I'd contact a few electrical contractors. I guess if I'm going to replace the panel I might as well do all the wiring too? Add GFCIs where needed etc. or is it typical to just swap out the panel? I don't want to cut corners. If wiring should be replaced I'd rather do it all.
 
  #19  
Old 10-17-13, 03:40 PM
Nashkat1's Avatar
Member
Join Date: Mar 2012
Location: USA
Posts: 8,470
I guess if I'm going to replace the panel I might as well do all the wiring too?
A house built in 1978 should have a ground conductor running with each circuit. If you have that there should be no need to replace any wiring.

Add GFCIs where needed etc. or is it typical to just swap out the panel?
This is a good time to add GFCI and AFCI protection where needed. Usually that's separate work but I'd add it in to a single contract because AFCI is almost always provided from breakers in the panel and GFCI can be. You should be able to save money by having it done right in one go.
 
  #20  
Old 10-17-13, 07:08 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,212
I don't want to cut corners. If wiring should be replaced I'd rather do it all.
Is your branch circuit wiring all copper? There weren't manyhome built that late that had aluminum wiring, but there were defintely some built. Aluminum branch circuit wiring would open up a whole new line of issues.
 
  #21  
Old 10-18-13, 10:48 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
CasualJoe,

I don't know. I've found a master electrician that I'm going to have come over to look at everything.
 
  #22  
Old 10-18-13, 06:08 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,212
I've found a master electrician that I'm going to have come over to look at everything.
When he opens the panel he can easily tell if you have any aluminum wiring. My guess is that you don't, but I have seen homes built as late as 1979 that did.
 
  #23  
Old 10-22-13, 04:51 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
Yeah it's all copper. We looked at it a few days ago. Gonna replace that breaker and mount an outlet for the oven then get an estimate on how much it'll cost to redo the panel and address that at a later date.
 
  #24  
Old 10-22-13, 06:53 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,212
Yeah it's all copper. We looked at it a few days ago. Gonna replace that breaker and mount an outlet for the oven then get an estimate on how much it'll cost to redo the panel and address that at a later date.
...............................................................
 
  #25  
Old 10-22-13, 06:56 AM
Member
Thread Starter
Join Date: Oct 2013
Posts: 12
CasualJoe that's what I said! Haha. I'm considering buying this house and I was going to factor in upgrade costs when I do it. I'm just glad it's going to be the lesser of the possibilities. I appreciate everyone's help on here. Thank you!
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'