To bond or not to bond neutral and ground in new electric service panel?

[STx]

Bonding screw? I don't think I have one. This Federal Pacific 100 amp sub-panel in the barn was installed about 1966 but it might have been a used salvage panel at that time, Dad was 'frugal'.

As I noted in the prior post the panel is fed by two hots and a neutral, no ground wire, then has its own good (recently replaced) grounding rod. All the neutral wires within go to the same neutral bussbar as does the grounding rod - and also a couple of green wires from circuits added later. (nearly all the sub-circuits are two-wire).

I assume this shared neutral/ground bussbar has the same effect as a bonding screw between neutral and ground in newer construction.

Is this scheme merely obsolete or a real immediate problem?

If the neutrals and grounds are going into the same buss, you're ok. It sounds like that's what you've got.

If the aren't, run a piece of #6 copper to connect the 2 separate busses.

 

[STx]

Thats odd. I guess they dont enforce national electric code in your neck of the woods. Technically its ok as thats how it was done for years, but this has not been a legal way to do it for quite awhile.

It depends on which h version of the code they're using. Some places are still on NEC 2008 or earlier.

 

[California]

If the neutrals and grounds are going into the same buss, you're ok. It sounds like that's what you've got.

If the aren't, run a piece of #6 copper to connect the 2 separate busses.

Thanks!

 

[crazyal]

If we are telling war stories my father's house (built in the late 60s so not that old with 100 amp service) had a 3 way switch installed so the living room outlet could have a light that was able to be turned on by either a switch at the front door or one by the master bedroom. The power came from the outlet to the switch by the front door then to the switch in the hall. The power came back down that same wire to the outlet controlled by the switch. They used 14/2 romex to connect the switch in the hall. The black wire was the hot return to the outlet while the white and ground wires connected the two 3 way switches. This somehow passed an inspector but it was easy as day to realize something was wrong. You should never see a bare ground wire connected to a terminal on a switch. It took a month or so before my father agreed to correct it.

 

[grsthegreat]

Well according to section 250 of the nat electric code, after 2008 revision on, a separate equipment grounding conductor MUST be run with the feeder and separate neutral no matter whet the situation. In the 2014 code (idaho hasnt adopted 2017 yet) its section 250.32.
In a grounded system there are no exceptions. So i dont see how your jurisdiction allows it...unless they are still using 2008 codes.

 

[fried1765]

Thank you! That describes what I see. So I don't have an immediate problem, but do have a system that is grossly out of conformance with modern specs.

Not only do I have that obsolete layout, worse is everything at both panels is Federal Pacific- a company now out of business because their stuff caused fires. I'm careful to never load any circuit to near breaker capacity. Thankfully this isn't our primary residence, we spend most of our time now at the ranch but have a house in town.

Photo: Worst example of how obsolete (and amateurish) the farmhouse wiring is, under the house in an area made inaccessible by a later remodel. I hope the wiring in the walls isn't like this.

I certainly hope that you NEVER permit yourself to fall asleep in THAT house !!!

 

[ultrarunner]

The old 1860 barn and other outbuildings have questionable wiring on the farm...

The first thing I did was put in a disconnect so I could sleep!

 

[California]

I certainly hope that you NEVER permit yourself to fall asleep in THAT house !!!

The little farmhouse is too screwed up to get ahead on repairs and too cute to tear down.

Last week I rebuilt a wooden screen door that was in 5 pieces after it had blown open and hammered against the porch rail. Carpentry and carpenter's glue, brass screws to compress the glued members, flat mending plates at the intersections in L or T-shapes, primer, and its back in service. Next trip, the top coat of paint. Why not buy a door? Because the doorway is lower than standard size. I've tried, nothing available can be cut down enough to fit. A custom screen door would be several hundred $.

New photo, below. I took this to show my kids how Rocky Racoon had tried to paw his way in a different screen door when we were away. (Our wet boot prints inside were subsequent to the dry racoon prints on the screen). This photo also illustrates the utter simplicity of everything. 1) we never put a finish on the t&g flooring when I helped Dad build this sunporch in 1961. 2) The plank inside the door is new. I recently noticed the flooring is springy there. I laid that plank down temporary to spread a person's weight until I can get underneath and rebuild whatever holds up that floor. That will mean going under the house past that scary light in the prior photo. I'll wait for dry weather before starting that project.

As I've noted I was advised by Dad to just bulldoze the place. Now I'm several years into retirement and I'm giving that advice to my kids. Thankfully our primary home in town doesn't have problems like this little, cute, labor-intensive farmhouse.

View attachment 535837

 

[hr3]

Well according to section 250 of the nat electric code, after 2008 revision on, a separate equipment grounding conductor MUST be run with the feeder and separate neutral no matter whet the situation. In the 2014 code (idaho hasnt adopted 2017 yet) its section 250.32.
In a grounded system there are no exceptions. So i dont see how your jurisdiction allows it...unless they are still using 2008 codes.

Agree 100 %

 

[Tractor Seabee]

If you are using metal conduit for a ground conductor between panels; you need a grounding bushing at each end that has a metal enclosure. that bushing then is bonded to the ground buss. There is a washer unit available for the same purpose if doing a retrofit to keep from disconnecting wires; the name escapes me right now. Aluminum conduit is a bad conductor as the joints tend to corrode badly and lose continuity.

It is amazing all the old stuff still working that is considered unsafe today. I have remodeled several old houses and updated them to current code. You have to use a lot of ingenuity on some things.

Ron