Backfeed for a panel that does not have such lugs?

I’ve called out the lack of a tie down for the backfeed breaker in the above panel. This is as Square D Homeline panel: I don’t see a listed way to tie a backfeed breaker. Is there such a listed way to do so? The factory 100A main breaker is marked “Vacant” on the deadfront.

HOM2040M100PCVP
HOMC21UC Cover

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Is this a auxiliary/remote panel with back-feed breakers?
Tie-downs required.

Ampacity smaller than the main breaker?
Are the neutrals shared?

This is an apartment subpanel, eight unit apartment.
There’s a 175 amp main->100 amp unit meter->50 amp fuse->this 50A backfeed breaker.

The question is it even possible to get a listed tie down for the Homeline panel pictured?

That clip appears to be listed only for certain HOM panels:

This retaining kit secures circuit breakers to the interior for HOM612L100F/S, HOM612L100RB, HOM48L125GC or HOM48L125RB load centers. Retaining kit is UL Listed. HOM1RK 785901076568

I saw that, but couldn’t see your panels #. If they make it for those, they may make it for others.

(Probably the same clip anyway…)

I don’t see any equipment ground conductors with the feeder how is this thing even grounded?

Since there is a 50 amp fuse ahead of the feeder they could have just used the 100 amp main breaker and eliminated the back fed breaker entirely.

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Or install a QOM50VH , since flipping a breaker is easier than replacing fuses.

This is a pre-ground building. None of the branch circuits have the third wire. The subpanel is a 3 wire feed. The ranges are 3 wire plugs with hot/hot/neutral.

That’s strange. A 3-wire feeder of this type to a subpanel within the same structure was never permitted. There must be an EGC with the feeder.

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The panel would still require to be bonded back to the disconnect.

Otherwise the panel could become energized.

Correct me if I’m wrong @rmeier2

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Correct the panel could become energized. In this case although not code compliant it would be safer if they installed a bonding jumper from the neutral to the enclosure.

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This was a one-to-one Federal Pacific Electric (FPE) subpanel swap, done apparently without permits. Triggered by an insurance company insisting on a 30 day fix.

The old panel had no exposed metal and was in a closet, the new one is as pictured on the opposite side of the closet wall.

What bonding grounding choice tradeoffs would you endorse @rmeier2 ?

  1. None. Grandfather 2-wire system, is what it is.
  2. Bond neutral to ground at the subpanel
  3. Bond the panel to a nearby cold water pipe.
  4. Replace main 50A fuse with a new 50A GFCI.

In this area 3 wire subpanel feeders were used well into the 1970’s, fully permitted professional jobs. Current work is 250.32(B)(1) Exception 1 if I remember right.

I would choose:
5. None of the above. The existing feeder without an EGC is not and never was code compliant and should be replaced. If I had to pick one from the four choices then #2.

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I’m left without an explanation why a huge fraction of the apartments from the 1960’s through some date in the 1970’s or early 1980’s never had four wire subpanels. Never.
How about in your area?

Note for the above panel even if an EGC came to the panel, no EGC exits the panel. The literal only thing that would be protected is the panel cover itself. The old panel cover was isolated, the new one is bonded (and in the living room as opposed to the closet).

Many old installations from the 60’s and 70’s had metal raceways or type AC as the wiring method for the feeder. The metal raceway or the cable jacket was the EGC. So the panel enclosure was properly grounded even if the branch circuits did not use a wiring method like the old NM cable without an EGC.

As the picture above shows, that’s not the case here. That’s clearly a cloth jacketed 3 wire feeder cable. No conduit.

The local building inspector (the City inspector) writes:

Bryce,

Running a new egc would be optimal. That said im not requiring it for a simple sub panel out of the closet thing. As long as there are no three prong outlets in the units. I’m not sure what the insurance guys think of that though…

Senior Building Inspector II
Community Development

Under the above rule should the neutral become disconnected and a box fault develop, the panel cover could become hot. At the same time it’s been like that since the 1960’s. What’s changed now is the panel moved to a more prominent place.

Does anyone sell a subpanel with an electrically isolated / composite plastic cover?

It never should been installed that way in the first place but like you said it’s been there for 60 years.

Does this work require an electrical permit and an electrical inspection? I know of no electrical inspector who would sign off on that.