No ground conductor in lighting branch circuit

[katwalatapan]

Hello,

I'm working on a renovation plan for a corridor area in my house. The building is relatively old (1980s) and during initial scoping, I noticed that there is no ground conductor on the lighting circuits for this area.

I wanted to inquire if installing a grounding conductor to the junction box via a threaded ground screw installed on the junction box would meet code? Then I could connect the grounding wire on the light fixture to this new ground conductor.

I'd appreciate your insights to resolve this issue and meet code.

Thank you.

 

[waross]

Not that old.
The 1956 Canadian Electrical code mandated loomex with a grounding conductor for all non-metalic wiring.
Was this home wired with pre 1950"s loomex or some other wiring method?
But back on track and let's deal with the situation as it exists.
A grounding conductor (suggest, green insulated #14 AWG copper) should follow the same route as the existing conductors and be as close as possible to the existing conductors to keep the impedance as low as possible.
When the conductor arrives at the ungrounded junction box, I suggest a three way splice;
The incoming wire, the wire out to the lighting fixture and a pig-tail to the ground screw in the junction box.
Older codes were quite forgiving as to the method of grounding/bonding circuits when retrofitting installations that were originally unbonded.
eg: A ground could be effected by a connection to any nearby metallic water pipe when upgrading an old installation.
Unfortunately I can no longer find these provisions in the Canadian code.
A friendly chat with the local UHJ may be in order.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[dpc]

Any house in US or Canada built after about 1960 should have ground wires run with each circuit. You can't create a new ground by just running a ground from the nearest metallic box. As Bill says, the grounding conductor needs to run along with the hot and neutral conductors back to the source (panelboard). Check to see if the bare ground wire was cut off in the box that serves the lighting fixture.

If the circuit is run in metallic conduit, the conduit can be used as a grounding conductor. Bad practice, but legal.

 

[waross]

You can't create a new ground by just running a ground from the nearest metallic box. As Bill says, the grounding conductor needs to run along with the hot and neutral conductors back to the source (panelboard)

I agree with dpc, however, if some of the wiring is properly grounded, and if the ungrounded circuit is fed from a circuit and junction box that is properly grounded, you may extend an existing ground from a properly grounded junction box or outlet.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[katwalatapan]

Thank you very much guys for your insights.