Floating ground ?

[dieseljeep]

Originally Posted by Kevin Kuehn

What scares me more than the old two wire system's, is the modern code approved twisted(wire nut) connections, and those crazy push in terminals on the back of duplex receptacles.

There's two types of wiring devices. Back wired and back stabbed. Back wired devices are the better quality devices. They have pressure terminals, that when using the back holes, you have to tighten the terminal screws to retain the connection.
The back stab devices, just have the holes to insert the wires. There's just a string type retainer to hold the lead. The screws are just there to connect the leads, if side wiring is desired. That is the best and preferred method. They're only listed for # 14 solid. The better back wired devices are listed for #12 or #14 solid or stranded.
Regarding wire nuts, they're only as good as the care used to install them. I've seen them burn up, from excessive load. That generally can be traced to improper installation.
Regarding K&T wiring: They claim that any K&T wiring, that remains unmolested, from the original installation is as safe as any other wiring system. The only negative is there's no ground available.

[old_coot88]

Some really scary stuff like house fires was recounted in the aluminum wiring fiasco.

[Electronic M]

I positively HATE back stabber outlets and switches! If they are not a problem then they are a problem waiting to happen. I've had those damn things kill power to other outlets down the line if you wiggled anything plugged into them the wrong way. When I replace any outlet or switch I always use the screw terminals...The extra time it takes is well worth it.

[dieseljeep]

Originally Posted by Electronic M

I positively HATE back stabber outlets and switches! If they are not a problem then they are a problem waiting to happen. I've had those damn things kill power to other outlets down the line if you wiggled anything plugged into them the wrong way. When I replace any outlet or switch I always use the screw terminals...The extra time it takes is well worth it.

The new code requires that all receptacle connections be pigtailed, when the circuit feeds more receptacles down the line, just for that very reason.
The code can't dictate the method of termination, as long as the device is U/L listed for back or side wiring.
AFAIC, these devices should loose their U/L listing, as I'M sure, it is the cause of electrical fires. Usually receptacles used for portable electric heaters or window air conditioners.

[wa2ise]

Originally Posted by maxhifi

I am assuming 1894 - that's cool, my great grandparents house had that sort of a set up too, ...

My grandma's house probably was built around 1894, but it still had the same wiring when my grandma checked out, in 1984. World's earliest BX cable, you look at it crosseyed, and the insulation turns to powder... The subsequent owner has upgraded the wiring, and installed air conditioning.

The house was a classic grandma's house, with a front porch, a back porch, full attic, and an added big kitchen in the back.

[dieseljeep]

Originally Posted by wa2ise

My grandma's house probably was built around 1894, but it still had the same wiring when my grandma checked out, in 1984. World's earliest BX cable, you look at it crosseyed, and the insulation turns to powder... The subsequent owner has upgraded the wiring, and installed air conditioning.

The house was a classic grandma's house, with a front porch, a back porch, full attic, and an added big kitchen in the back.

I lived in a few houses like that, being the oldest section of town.
Many of them had additions, as well.
If the home has that early BX, it was wired for electricity, well after it was built. The real hi-class homes had gas piping in the walls. Slightly newer homes had K&T wiring, as well as gas lines.
The old family home was wired in the mid-1920's. Back then, the electric utility, subsidized the wiring installation.

[maxhifi]

Originally Posted by dieseljeep

The new code requires that all receptacle connections be pigtailed, when the circuit feeds more receptacles down the line, just for that very reason.
The code can't dictate the method of termination, as long as the device is U/L listed for back or side wiring.
AFAIC, these devices should loose their U/L listing, as I'M sure, it is the cause of electrical fires. Usually receptacles used for portable electric heaters or window air conditioners.

Really? I hate how the solution to poor workmanship and poor product design is always more rules, that's a complete waste of effort and will require more deep boxes than usual.

[Reece]

I've seen electrical receptacles in old houses crumble into pieces due to overheating from using a 120V air conditioner.

[maxhifi]

I've seen "back stabbed" receptacles fail due to electric space heaters, but I think pigtails on every receptacle is kind of a heavy handed solution to an issue which has more to do with bad terminations. I could see making a pigtail for the neutral, but for both hot and neutral is serious overkill.

[dieseljeep]

Originally Posted by maxhifi

I've seen "back stabbed" receptacles fail due to electric space heaters, but I think pigtails on every receptacle is kind of a heavy handed solution to an issue which has more to do with bad terminations. I could see making a pigtail for the neutral, but for both hot and neutral is serious overkill.

I think you're referring to MWBC, multi-wire branch circuits, where a shared neutral is used. The code also changed on that, as well. MWBC's, now require a double pole breaker.
Regarding the pig-tailing of the neutral only, I've seen the hot conductor also burn up. A termination, that is subjected to a continuous heavy load is subject to heating and becoming loose. If all that's being used in a termination is a tiny bent piece of brass, holding the connection, any heating will cause it to lose it's tension.

[maxhifi]

Originally Posted by dieseljeep

I think you're referring to MWBC, multi-wire branch circuits, where a shared neutral is used. The code also changed on that, as well. MWBC's, now require a double pole breaker.
Regarding the pig-tailing of the neutral only, I've seen the hot conductor also burn up. A termination, that is subjected to a continuous heavy load is subject to heating and becoming loose. If all that's being used in a termination is a tiny bent piece of brass, holding the connection, any heating will cause it to lose it's tension.

Yes, that's just what I meant, for two or three pole multi wire branch circuits. I wonder if they need three pole breakers for three phase multi wire circuits now? This will be really annoying in some circumstances - say in an office if someone uses a plug in space heater and trips the three pole breaker to three or six desks, killing power to all the computers!

I don't support the use of "back stab" connections at all.. when I have wired houses I always use the screw terminals, even if it will take a little bit of extra time. I can't see how screw terminals are any better or worse than a wire nut and a pigtail though, provided it's a quality receptacle and they are torqued properly.

[N2IXK]

Backstabs should be banned, IMO. Has anyone else seen the REALLY scary PRC ones that don't even HAVE the screw terminals as an option?

The backwired pressure clamp ones are the way to go. Almost as fast to install as backstabs, and easier to disconnect without unlooping/bending the wire.

Rewired a house (Northern NJ) one time that had been converted from gas lighting to electricity (sometime in the 1920's). The sparkies reused the existing gas pipes as conduit for the lighting circuits! How they managed to pull wire through plumbing ells without shredding the insulation I have no idea, but this installation was in use up until around 2000. House went up for sale and buyers insurance Co. demanded a rewire.

Service equipment looked "fabricate on site", consisting of a slate panel with 6 open blade knife switches and bare wire fuses. A small hank of spare "fuse wire" was hanging neatly on a hook nearby. Looked like thin (~18 AWG) solid core solder. All enclosed for safety in an enclosure made from asbestos board! Insurance demanded that be professionally abated, as well.

[dieseljeep]

Originally Posted by maxhifi

Yes, that's just what I meant, for two or three pole multi wire branch circuits. I wonder if they need three pole breakers for three phase multi wire circuits now? This will be really annoying in some circumstances - say in an office if someone uses a plug in space heater and trips the three pole breaker to three or six desks, killing power to all the computers!

I don't support the use of "back stab" connections at all.. when I have wired houses I always use the screw terminals, even if it will take a little bit of extra time. I can't see how screw terminals are any better or worse than a wire nut and a pigtail though, provided it's a quality receptacle and they are torqued properly.

Right at this point, the code doesn't address the MWBC ruling regarding, three phase 120/208 network, general use circuits.
Being a retired industrial-commercial electrician, I had to stay current, with the code changes. Might be a little rusty now, being retired for eight years.

[wa2ise]

Originally Posted by maxhifi

I've seen "back stabbed" receptacles fail due to electric space heaters,...

Wonder if they have space heaters in the ISS Space Station?
I'm sure they don't have backstabbed outlets up there.