Old Romex Wire

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stevenje

Senior Member
Location
Yachats Oregon
I ran across a type of romex wire that I have never seen before. It is the old black cloth covered type. The hot and neutral conductors are copper but it has a #16 Al ground conductor. At first I thought it was a tinned copper conductor but after removing it from the ground bar and cutting the end off conductor, it is AL. Has anyone ever seen this type of romex before? According to the home inspection report the home was built in 1935.
 

ceb58

Senior Member
Location
Raeford, NC
I ran across a type of romex wire that I have never seen before. It is the old black cloth covered type. The hot and neutral conductors are copper but it has a #16 Al ground conductor. At first I thought it was a tinned copper conductor but after removing it from the ground bar and cutting the end off conductor, it is AL. Has anyone ever seen this type of romex before? According to the home inspection report the home was built in 1935.
That's about right. The insulation is very brittle in light boxes due to the heat over the years. It will get you in a bind changing out fixtures.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
That's about right. The insulation is very brittle in light boxes due to the heat over the years. It will get you in a bind changing out fixtures.
I also think that you should not change out any two wire receptacles for grounding receptacles while relying on that ground wire. Whether you should even connect it at the outlet if wiring a GFCI receptacle is a question I pose for those with more experience in old residences.
 

kwired

Electron manager
Location
NE Nebraska
I also think that you should not change out any two wire receptacles for grounding receptacles while relying on that ground wire. Whether you should even connect it at the outlet if wiring a GFCI receptacle is a question I pose for those with more experience in old residences.

I don't have as much of an issue with using the 16AWG ground wire, but the fact the OP said this one was aluminum would be a first for me also. I have a hard time believing it is aluminum first, but if it is I also have a hard time believing it is 16 AWG. Only place I have seen that small of an aluminum conductor is the sheath bond wire in AC cable. Not trying to call OP a liar, but is it possible it is something other than aluminum and/or is intended to be something other than an equipment grounding conductor? Steel strand for aerial support? Though not all that likely either.
 

jmellc

Senior Member
Location
Durham, NC
Occupation
Facility Maintenance Tech. Licensed Electrician
I cannot imagine something that old having AL ground. I have seen tinned or nickel plated copper quite often in old wiring. Try cutting it in several places and see if some CU does not shine out from the center. AL is usually very brittle too, in small sizes. Try repeatedly bending a short piece around your finger. It should breake after a dozen bends or so. I have seen a few pieces of old BX with an apparant AL ground, from about the 60's.
 

Blaer

Member
Location
St. Louis, Mo.
That sounds like the wire I found during a trailer rewire.

The mobile home was pre-1974,and thus before HUD or UL got involved. There was no doubt; primary wires were #14 copper, while the ground was a #16 solid aluminum wire.

Just opening the boxes was often enough flex to cause the aluminum wire to break - often right at the crimp ferrule.

Related, I've also encountered the rare home (late 60's) where the Romex had a reduced size copper ground wire.

It was legal at the time, so I see no reason to treat the system as being without an EGC. The joker is that you won't always know if you cracked the wire closing up the box.

1935 with any sort of ground wire? No way- someone did some work since then. You NEVER saw a ground wire until the late 50's. Aluminum had it's heyday in the early 70's. The late 60's was when the reduced ground was popular.
 

kwired

Electron manager
Location
NE Nebraska
I cannot imagine something that old having AL ground. I have seen tinned or nickel plated copper quite often in old wiring. Try cutting it in several places and see if some CU does not shine out from the center. AL is usually very brittle too, in small sizes. Try repeatedly bending a short piece around your finger. It should breake after a dozen bends or so. I have seen a few pieces of old BX with an apparant AL ground, from about the 60's.
AC (BX) does have an aluminum "bonding" wire inside. It's not intended to be connected in your enclosures, it is merely there to short each turn of the spiral sheath together to make the sheath have less impedance. The combination of the sheath and this bond wire are the equipment grounding conductor of the cable. I don't know when they started making it that way, old cable without plastic insulation on the conductors did not have this bond wire.

That sounds like the wire I found during a trailer rewire.

The mobile home was pre-1974,and thus before HUD or UL got involved. There was no doubt; primary wires were #14 copper, while the ground was a #16 solid aluminum wire.

Just opening the boxes was often enough flex to cause the aluminum wire to break - often right at the crimp ferrule.

Related, I've also encountered the rare home (late 60's) where the Romex had a reduced size copper ground wire.

It was legal at the time, so I see no reason to treat the system as being without an EGC. The joker is that you won't always know if you cracked the wire closing up the box.

1935 with any sort of ground wire? No way- someone did some work since then. You NEVER saw a ground wire until the late 50's. Aluminum had it's heyday in the early 70's. The late 60's was when the reduced ground was popular.
OP said this was a cloth covered cable. I have never seen aluminum conductors in a cable with cloth covering. I have seen EGC's in cloth covered cables. They usually only fed 240 volt equipment though. For some reason 120 volt equipment had no EGC but 240 volt did.
 

guschash

Senior Member
Location
Ohio
My old house had reduce ground wire. It was builtnin 1964. Also had federal pacific panel, the whole sub-division did. Never heard of any fires or problems and I knew all my neighbors.
 
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