Running TMCC/Legacy in an old house

Years ago many older homes had their kitchen/bath outlets upgraded by snaking single ground wires from the Service Panel into the outlet boxes and replacing the existing two wire receptacles with a modern 3-prong unit. Subsequent to the 1965 Code change regarding grounded circuits many municipalities approved the procedure when performed by qualified electricians.

I have no clue as to whether the procedure is still allowed but if done properly it was effective and safe assuming the circuitry was otherwise in good shape. 

Mike CT can enlighten us on the current circumstances regarding this procedure.

Upgrades are allowed, but you can't snake one wire - you have to run individual ground wires from the breaker box to the outlets. That's what the electrician did in our house, but because of California home construction techniques of the day, it's not easy and he was only able to do two downstairs outlets. Upstairs outlets were just not cost-effective. They also installed a properly grounded outlet outside, and I tapped off that when doing the garage.

A friend of mine decided to tackle the same job in his 1950s home, and then decided after a few attempts that the easiest way to do it was to tear out every piece of sheet rock in the house first.

Fred

Fred

I didn't write it very well but the TVA System allowed a single ground wire per circuit, one from each breaker controlled circuit that could have more than a single receptacle on it. This was way back in the day so I could be wrong. 

So, you definitely have only 2 conductor wiring?

Where's the panel located and where's carpet central get set up?

There should be a sewage drain vent running up to the attic. There's usually enough space to fish a cable next to it. Create a new circuit to a junction box. Then you can drop into the upstairs wall from the attic junction box. You only need 14-3 for a 15A circuit.

Okay, rechecking the Legacy Command Base manual, I see that it's power supply is three-prong. I was wondering where the ground fit in, since I wasn't seeing it in the diagrams in Barry's book.

So, barring major rewiring projects (believe me, in my house, all wiring projects are major) would there be anything wrong with using a long (20') extension cord to power it?

Fred

Extension cord should be fine.

Try to find a 12 gauge extension cord. If it's a pain, 14 gauge will do.

The 12 will supply ~10 amps, the 14 ~6amps.

 The real concern behind TMCC/ Legacy ground is that one side of the signal is sent through the ground lug of the base. It is then "broadcast" through the ground wiring in the walls of the room/ building that the system is located in.

Having said that, there are folks that run TMCC/ Legacy outside. I'm not sure if that is dependant on how close the layout is to the house to operate correctly.

I believe you only need to run the command base off of a grounded outlet and that draws minimal current, so virtually any extension cord should be OK. It's an antenna, for radio frequency, more or less.

There are 3 wires connecting outlets, a hot wire, neutral wire, and ground.

The neutral and ground are tied together at the box and are the same from an electral point.

Replace the 2 prong outlet with a 3 prong outlet and connect the center prong

to the neutral prong. Its not code but it will work from an electrical point.

Depending on the age of the wiring, there may be ground wires (reduced size) in the electrical outlet boxes, just not applied to a (3)prong grounded outlet.  Late 40's wiring though early 60's, kitchen, basement, and maybe the bathroom.

Grounds are designed as a safety path. An interesting note about old, (not working), (2) prong outlets, is that they are to be replaced with a (2) prong outlet.