Service Upgrades

[meterman]

I work in the Meter Department for Norheast Utilities in Connecticut. Sometimes while changing meters in old houses the customer will ask me how they can get ground protection for their old wiring. Some of these houses are old enough to have knob and tube and some have 2 wire romex without a ground. Can someone tell me what year it became code that romex was required to change from 2 Wire to 3 wire with the ground included and can the house circuits with 2-wire romex that now require GFI's like bathrooms and outside receptacles be protected by installing GFI circuit breakers at the main panel when they upgrade the srevice

 

[tom baker]

Re: Service Upgrades

There are several methods NEC Article 250 Grounding allows when replacing a 2 wire recptacle with a 3 wire. An equipment grounding conductor (green wire)can be run to an acceptacble grounding electrode per Section 250.130C

"(C) Nongrounding Receptacle Replacement or Branch Circuit Extensions. The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following:
(1) Any accessible point on the grounding electrode system as described in 250.50
(2) Any accessible point on the grounding electrode conductor
(3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates
(4) For grounded systems, the grounded service conductor within the service equipment enclosure"

The safest method is to replace the non grounded repctacle with a GFCI. It does not have a ground and this can effect the operation of TVSS devices.
A GFCI does not require a ground to operate.

If it were me I would install GFCI's and feed downstream from them to protect the entire circuit.


I don't know when romex with ground was inroduced into the NEC.