Adding grounding wire in older house

[Marty Lustig]

I'm relatively new to the Forum, so if this topic has been covered in depth previously, just point me in the right direction, please. I'm working in an older home (1950's) wired with Romex (2 wire without ground) for much of it. Where a true equipment ground is not required, I've put in GFCIs (combined with AFCI's in most places). However, there are some places where having an equipment ground would be very desirable...various electronic equipment. I'm looking for some "best" (or at least "good") practices for running an equipment ground back to panel. Getting TO the panel from most of the critical need locations would (naturally) be extremely difficult. I CAN get to the #4 running from panel to cold water pipe into house quite easily. Questions: 1. Can I run a grounding green #12 from JBox through same opening/clamp as Romex is going, wire tie the grounding wire to the Romex for as much as I can, then "branch" over to the #4 and connect with a split-bolt approved for the #4. 2. What about locations that are not near anything that is grounded. Does anyone run a grounding wire outside the house and eventually to the panel or to the #4 running to water pipe?

 

[user 100]

I'm relatively new to the Forum, so if this topic has been covered in depth previously, just point me in the right direction, please. I'm working in an older home (1950's) wired with Romex (2 wire without ground) for much of it. Where a true equipment ground is not required, I've put in GFCIs (combined with AFCI's in most places). However, there are some places where having an equipment ground would be very desirable...various electronic equipment. I'm looking for some "best" (or at least "good") practices for running an equipment ground back to panel. Getting TO the panel from most of the critical need locations would (naturally) be extremely difficult. I CAN get to the #4 running from panel to cold water pipe into house quite easily. Questions: 1. Can I run a grounding green #12 from JBox through same opening/clamp as Romex is going, wire tie the grounding wire to the Romex for as much as I can, then "branch" over to the #4 and connect with a split-bolt approved for the #4. 2. What about locations that are not near anything that is grounded. Does anyone run a grounding wire outside the house and eventually to the panel or to the #4 running to water pipe?

A separately run egc is kosher----See 250.130(C)

 

[buzzbar]

When I’ve had this type of situation cross my path, I always say that if you’re going to go to the trouble of running ground wires, you might as well replace the old “romex” with new NM-B wire. Sure, it’s more costly, but that old wire is over 60 years old, and the labor is about the same.

 

[qcroanoke]

When I’ve had this type of situation cross my path, I always say that if you’re going to go to the trouble of running ground wires, you might as well replace the old “romex” with new NM-B wire. Sure, it’s more costly, but that old wire is over 60 years old, and the labor is about the same.

+1

 

[Knuckle Dragger]

When I’ve had this type of situation cross my path, I always say that if you’re going to go to the trouble of running ground wires, you might as well replace the old “romex” with new NM-B wire. Sure, it’s more costly, but that old wire is over 60 years old, and the labor is about the same.

+2

 

[winnie]

I agree with the general feeling that running a new romex is preferable to running a separate ground wire, since the materials cost is small and _usually_ it is essentially the same amount of labor. However the OP specifically said:

Getting TO the panel from most of the critical need locations would (naturally) be extremely difficult. I CAN get to the #4 running from panel to cold water pipe into house quite easily.

I know that a separate EGC is permitted for retrofit, but I don't recall the details, eg. can this retrofit EGC be connected to an accessible GEC or does it need to go back to the panel.

-Jon

 

[Dennis Alwon]

I agree with the general feeling that running a new romex is preferable to running a separate ground wire, since the materials cost is small and _usually_ it is essentially the same amount of labor. However the OP specifically said:



I know that a separate EGC is permitted for retrofit, but I don't recall the details, eg. can this retrofit EGC be connected to an accessible GEC or does it need to go back to the panel.

-Jon

It can be connected to either a grounding electrode conductor or back to the panel

250.130(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) An equipment grounding conductor that is part of another
branch circuit that originates from the enclosure
where the branch circuit for the receptacle or branch
circuit originates
(5) For grounded systems, the grounded service conductor
within the service equipment enclosure
(6) For ungrounded systems, the grounding terminal bar
within the service equipment enclosure

 

[winnie]

Another thought: the desire here is to add an EGC for electronic equipment which might be in some way 'sensitive', eg. using the EGC as a reference for noise filtering or the like.

Having an EGC that does not follow the circuit conductors creates a 'loop' which can act as an antenna, picking up noise through magnetic coupling. As a design decision you may need to replace the run to get 'proper' receptacles for this equipment anyway.

-Jon

 

[Marty Lustig]

Thank you all for excellent input. Very much appreciate the citation in the code. The electronic equipment needs to be protected by surge protectors, so that is primary reason for equipment ground. The specific ref to 250.130(C)(4) "An equipment grounding conductor that is part of another branch circuit that originates from the enclosure where the branch circuit for the receptacle or branch circuit originates" may present a number of possibilities. Re re-wiring: I'd very much like to do that, and I have done that in a few places. But to do the difficult areas would require opening walls, ceilings, etc.