No EGC on feeder to sub panel

[Cleveland Apprentice]

Hi,

It's been awhile since I've been on this site. I ran into a situation where customer wants to change out a small Edison fuse panel (two 30 amp fuses) and replace it with a small breaker panel. This sub panel is in the garage and there is no way to replace the feeder without tearing out drywall. The current fuse panel has no EGC and no EGC within 10/3 NM. The panel is not grounded. The branch circuits have no EGC either. Another electrician suggested putting a gfci breaker on the existing feeder in main panel. Just wondering what your thoughts are. Thanks

 

[user 100]

Hi,

It's been awhile since I've been on this site. I ran into a situation where customer wants to change out a small Edison fuse panel (two 30 amp fuses) and replace it with a small breaker panel. This sub panel is in the garage and there is no way to replace the feeder without tearing out drywall. The current fuse panel has no EGC and no EGC within 10/3 NM. The panel is not grounded. The branch circuits have no EGC either. Another electrician suggested putting a gfci breaker on the existing feeder in main panel. Just wondering what your thoughts are. Thanks

Is the 10/3 w/o egc the feeder? If so, that's no longer legal when you change that sp. Another issue here is why the need to get away from the fuse panel anyway? What is the fuse panel feeding exactly? And what do you mean when you say the old sp isn't "grounded"- just no egc(s) and/or the can is floating or...?

 

[ActionDave]

Refeed it or don't touch it.
Since it's in the garage why not surface mount the panel and run conduit till you have to drop in the wall at the main panel?

 

[Little Bill]

Is the 10/3 w/o egc the feeder? If so, that's no longer legal when you change that sp. Another issue here is why the need to get away from the fuse panel anyway? What is the fuse panel feeding exactly? And what do you mean when you say the old sp isn't "grounded"- just no egc(s) and/or the can is floating or...?

If the install was legal as a 3-wire when installed, what makes it not legal just because you change the panel? You're not messing with the feed, just the fuse/panel box.

 

[user 100]

If the install was legal as a 3-wire when installed, what makes it not legal just because you change the panel? You're not messing with the feed, just the fuse/panel box.

My thing here is that he is wanting to swap it out for a reason- if he needs an egc, the 3 wire has to go. Otherwise he could just leave the old setup alone entirely, and just gfci where needed on the old bcs if worried about the shock protection.

 

[Little Bill]

My thing here is that he is wanting to swap it out for a reason- if he needs an egc, the 3 wire has to go. Otherwise he could just leave the old setup alone entirely, and just gfci where needed on the old bcs if worried about the shock protection.

I agree if he needs an EGC but didn't the "old rules" allow the grounded conductor to bond to the panel then also have a ground bar? You could run EGC then, just like at the main service.

And you didn't answer my question of what makes it not legal just because of a panel change. There a lot of things he can do I just wonder why it would be not legal to leave the feeder as is. Assuming it was legal when it was installed.

 

[user 100]

I agree if he needs an EGC but didn't the "old rules" allow the grounded conductor to bond to the panel then also have a ground bar? You could run EGC then, just like at the main service.

And you didn't answer my question of what makes it not legal just because of a panel change. There a lot of things he can do I just wonder why it would be not legal to leave the feeder as is. Assuming it was legal when it was installed.

Not ignoring your question.

What is getting me here is that I don't know if or when a 3 wire feed w/ neutral as egc to a sub in same structure was legal(???)- in sep structure I know it was up until fairly recently- now for your question: wouldn't think so if only for a strict sp panel only change out if it was legal when installed.

 

[ActionDave]

Not ignoring your question.

What is getting me here is that I don't know if or when a 3 wire feed w/ neutral as egc to a sub in same structure was legal(???)- in sep structure I know it was up until fairly recently- now for your question: wouldn't think so if only for a strict sp panel only change out if it was legal when installed.

AFAIK it was never legal in the same structure, but was not uniformly enforced.

 

[user 100]

AFAIK it was never legal in the same structure, but was not uniformly enforced.

Thanks.

Since it isn't legal today and probably never was , then the op effectively has his answer about that old feed if he needs an egc. Wondering too what those (2) 30 amp fuses are feeding.

 

[Cleveland Apprentice]

Sorry guys, just to clarify the feeder is 10/3; red, blk, wht, but no grd. I'm not sure if I can bond the neutral with bonding screw and still be considered grandfathered in because I am not changing the feeder. I was going to error on the side of caution and just gfci the feeder with a 2 pole 30 amp gfci breaker at main panel.

The sub panel isn't grounded at all (floating)

The sub panel needs to be changed because of corrosion and overloaded due to small size. The two 30 amp fuses were feeding 4 or 5 #12 BC's and another reason why I need to change it out and put 20 amp CB's in

Thanks

 

[user 100]

Sorry guys, just to clarify the feeder is 10/3; red, blk, wht, but no grd. I'm not sure if I can bond the neutral with bonding screw and still be considered grandfathered in because I am not changing the feeder. I was going to error on the side of caution and just gfci the feeder with a 2 pole 30 amp gfci breaker at main panel.

The sub panel isn't grounded at all (floating)

The sub panel needs to be changed because of corrosion and overloaded due to small size. The two 30 amp fuses were feeding 4 or 5 #12 BC's and another reason why I need to change it out and put 20 amp CB's in

Thanks

I know it seems counterintuitive to even entertain the thought of leaving something floating but imo, don't think you can bond the new sub panel panel to the neutral in that old nm- you really need to pull new cable/ do what ActionDave said above in post #3.

 

[kwired]

Does GE still have those small 4 - 6 circuit panels in a non metallic cabinet?

 

[Little Bill]

AFAIK it was never legal in the same structure, but was not uniformly enforced.

I'm not seeing where the OP says its in the same structure. I was talking about the rules (old) for a separate structure/building.

 

[kwired]

I'm not seeing where the OP says its in the same structure. I was talking about the rules (old) for a separate structure/building.

If it was a detached garage you could have bonded the neutral at the garage.

Supply cable was NM though - probably in same structure.

 

[mwm1752]

I agree if he needs an EGC but didn't the "old rules" allow the grounded conductor to bond to the panel then also have a ground bar? You could run EGC then, just like at the main service.

And you didn't answer my question of what makes it not legal just because of a panel change. There a lot of things he can do I just wonder why it would be not legal to leave the feeder as is. Assuming it was legal when it was installed.

The AHJ has the ability to make judgements on life safty issues -- If the one time compliant installation is deemed a life safty hazard by the AHJ that would make it not legal. --
2016 appliances & electronics are completely different from the 1940's so would you consider a 1940 feeder without an EGC to a new panel safe?
Lets say there was a nm type cable without a ground as an installation, code has ways of upgrading devices in order to not replace a legal installation, but now you find rodents have damaged the wire exposing and damaging the conductor, was it legal when installed(yes) should it be replaced due to damage?(yes) IMHO

 

[user 100]

If it was a detached garage you could have bonded the neutral at the garage.

Supply cable was NM though - probably in same structure.

Did a little research on this today and found out that many, many years ago it was accepted practice in a lot of areas to leave the sp can in same structure floating- kind of surprised me- apparently it hasn't been NEC legal to use the neutral as egc in same structure sps since at least the 1930's.

Guess you really do learn something new everyday.

 

[Cleveland Apprentice]

Yes, garage is in same structure

 

[user 100]

Yes, garage is in same structure

Then no can do for sure w/ that same feed if replacing that old sp- forget about the grandfathering. You are installing a new panel and by the current NEC, that replacement can has to be bonded, and there is no exception that allows you to use the neutral in the old cable to do so in same structure as main. Not the answer you wanted but remember that once you touch it you own it-don't leave it floating and don't use that neutral for case bond. Need to Re-feed.

 

[jumper]

Sorry guys, just to clarify the feeder is 10/3; red, blk, wht, but no grd. I'm not sure if I can bond the neutral with bonding screw and still be considered grandfathered in because I am not changing the feeder. I was going to error on the side of caution and just gfci the feeder with a 2 pole 30 amp gfci breaker at main panel.

I do not see how that would make the install legal. Nothing short of a new 4 wire feeder seems to acceptable/legal AFAICT.

 

[Michael15956]

What's interesting is GFCI protecting the ungrounded sub-panel. Code aside, it seems safe, we are allow to do it for an ungrounded receptacle.