I worked on the 1956 wiring in the house again, replacing the garbage disposal.
When did solid replace stranded wiring in house electrical systems? I hate that stuff, particularly when it is 70 years old.
Smaller gauge cable - 10AWG or smaller - is typically solid, wire in conduit is more likely to be stranded. This has always been the case in my experience.
Pretty much since NM cable (Romex) became the standard for residential construction.
Thanks.
This 70 year old stranded breaks when it is flexed. It was stranded from the switch, but the run to the switch is solid. I presume that run was made when the disposal was installed in the 70s or 80s.
Sounds like a handyman special. Is this cable or individual wires?
They fed the switch with #12 two conductor with ground solid from the dishwaser. They fed the disposal with stranded cable, #10? apparently left over from original construction. That’s what is falling apart. The insulation cracks as it is bent… The switch is wired in the “modern” fashion, the cable goes to the switch and the cable to the disposal in spliced in the box. A light switch I replaced last year had just the switch with two wires and the splice occuring inside the light box.
Romex was invented in 1928 but apparently didn’t become the standard until the 60s.
Our house on the farm had cloth sheathed wiring. Probably run through the walls on insulators. And four fuses for the entire house. You know the scene in A Christmas Story when the Old Man plugs in the leg lamp into the already-overloaded outlet? That was my childhood.
Over here in the UK, all fixed electrical runs - those between the main board and the outlets or appliances - are solid, Flexible wires like the connectors from outlet to appliance, or extensions are always stranded.
It seems obvious to me that since solid is cheaper and suffers slightly fewer losses than stranded, it makes sense to use it where it will not be subject to flexing.
I think stranded was easier to twist together and slap a wire nut on. The connection I describe in the most has stranded twisted onto solid with tape wrapped around it.
That stuff is called “knob and post” wiring. It is still “legal” or whatever for existing installations, so long as the insulation is in good shape, or so I’ve read. Maybe that has changed? There isn’t any thing “wrong” with it per se. The main problem is vintage electrical systems aren’t up to the increased current demands.
I’ve always wondered why houses haven’t burned down from rats touching both conductors at once and burning. Perhaps the conductors are further apart than I think.
Knob and tube. The “post” and the “knob” are the same thing. The tube is used where the wire runs through framing.
Looks like a rat could fry himself quite easily.
My parents house was built in 1964/65. We used BX cabling with 12 gauge solid wiring. Some areas of the house used metal conduit with 12 gauge solid wiring (long uninterrupted runs). The house was built with real journeymen carpenters and still stands solid as a rock.
The house my wife and I have was built in 1999 and we’ve owned it since 2005. It uses Romex with 14 gauge solid wiring. Every time I finish using the vacuum cleaner, as I unplug it from the wall, the plug is warm. Never happened in my parents house. And oh, my house today was built like crap compared to my parents home. If my wife and I build our next home, I will pay extra for BX cabling with 12 gauge solid wiring.
Why not just use 12 gauge Romex?
Using armored cable is pretty pointless, unless you plan on filling your wall full of holes.
My parents’ house was built in 1895 or so and was knob-and-tube. When they retired and went to sell it in 2007, they were told that to get insurance, a new owner would have to have it rewired. They had been grandfathered. I’m still not sure how that got done: good old plaster walls, so I assume lots of cutting. What electricians call “minor drywall damage”, i.e., any hole that they can’t fit both head AND shoulders through!
The buyer knew what he was getting into, though, and we’ve talked to him since and he’s happy. So I guess it wasn’t as bad as I feared.
My current house, built in 1986, has all 12 gauge for 15 amp circuits. Over designed. But never had any problems!
As others have said, I think it’s always been the case that solid wire is usually used for branch circuits—anything smaller than about 10 AWG. It’s considerably more difficult and less reliable to land stranded wire on most switches, receptacles, and other devices. The terminals thereon are pretty much designed just to have solid wire landed on them.
As wires get bigger, solid wire becomes unmanageable due to excessive stiffness. I do not think that solid wire comes in any larger size than 8 AWG.
On a related note, larger wires cannot go anywhere, because they are stranded.
Without a wire nut? Just twisted together, with only tape on it? That’s not good; that’s not safe, that’s not legal.
You’re telling me?