My in-laws want to replace old electric range (240V, 40A) with one cooktop and one wall oven (240V, 30A, each). The old range was powered by a circuit from a 40A breaker in the sub-panel sitting on a 240V, 100A circuit without the ground, as in the photo (the other 40A breaker is not used).

The "purple" line in a pipe from the main panel enters this sub-panel, then leaves it as the "yellow" line that continues to another box upstairs, with the ground wire outside as in the photo. The new appliances have to be grounded.

My question is: If I run new grounded circuits from the two 40A breakers, can I connect their ground wires to the ground wire that hangs outside as in the photo? Will probably also replace the old breakers by 30A ones.

Thanks, h.

 

That panel doens't look like it was wired correctly to begin with.

Yellow is in the conduit (pipe) and purple is not in the conduit in your picture. Do you have them backward?

The conduit has to be attached to the panel. You cannot have individual wires out of of the panel or junction box like that.
Also, all cables entering the panel has to be clamped.

There has to be a ground bus bar (sold separately) has to be installed to the panel and all ground wires has to connect to it. If there is any bonding screws or tap boding ground and neutral bus bar, it has to be removed in subpanel.

Existing ground wire will not do any good if it doesn't have ground wire coming from the main panel.
You will have to run another ground line in yellow conduit.

Replacing that panel is highly recommend. That is discontinued stab-lok breakers and they are known to cause fire. Also, whole new main lug panel is much cheaper than buying replacement breaker for this panel.
Double tapping is not allowed in most modern main lug panels, but you can install feed through lugs in them.

 

Thank you, Lambition! Yes, you are right, I got it backwards. The "yellow" cable in the conduit comes from the main panel; the "purple" continues on to another panel.

The bare ground wire comes out of the conduit, I believe it is the ground wire from the main panel. I mean it has to be because these cables in this conduit is where the power comes from.

Yes, this is clear. Will see if I can install a ground bus bar to connect the ground wire properly.

I was not going to double tap. There is no need in double tapping because the other breaker (on the right) is not used for anything. I would just connect a new cable from it. Would this be acceptable?

Thanks, good to know. Replacing a breaker sounds much easier though.

 

That would not be possible since the other end of that ground runs to NM cable. Unless someone stripped NM of same length as wires in the conduit, ground will not run to the panel.
Try pulling that ground wire. It was probably used pushed few inches in the conduit.
Is that metal conduit? If so, and the conduit runs continuously to the main panel using metal conduits, it can be used as ground.

I was referring to double tapping of main lugs feeding the panel. That is not allowed in most panels.
Either you can use feed through lugs or use some other wire connectors (Polaris connectors, split nut, etc..) with pigtails.

 

Appreciate your commets, Lambition! I'm afraid you might be right about the fake ground wire. Will try to pull it.

 

Is that an FPE Stab-Lok panel? The breakers look like it.

If it is, you should definitely consider replacing it during this process. Those panels have a high incidence of breakers not tripping when they should and overheating and causing fires. For a small panel like that, it would be pretty cheap and easy to replace, and well worthwhile.

(Unless I'm mis-identifying it of course!)

 

Thank, Zorfdt! Below is the photo. As far as I can tell you are right!

 

Lambition, my FIL is quite impressed! He now suspects that you are the one who installed it this way -- how else would one know that that wire is fake.

He's still reluctant to change the entire Stab-Lok panel, just put new 30 amp breakers and pull second line. Will see if I can find new breakers.

Again, thanks for you help. H.

 

Sure you can find new 30 amp breakers under the Connecticut Electric brand name, but the cost of two 30 amp breakers will be more than the cost of a new panel. I would change the panel too and get the old FPEs out of my house.

 

I'll join the chorus to say replace the FPE panel. Both the panels and breakers have significantly higher failure and fire rates than other panels of similar age. It's a storied history with FPE, but the bottom line is they have known engineering failures for decades. Experts believe the original safety certification documents (in the US at least) were forged, and the product line has been the target of numerous investigations, lawsuits and similar action over the years. UL withdrew certification in the 80s after discovering the fraud by FPE executives, and now the US-CPSC recommends full panel replacement as the only safe solution.

 

Your latest picture shows metal conduit. If that metal conduit runs all the way to the main panel, it will serve as ground.
The conduit just needs to be extended to the panel using various fittings or flexible metallic conduit.
That ground wire may have be pushed in the conduit in attempt to connect ground wire.

To correct wires entering the panel, you will have to pull all the wires out anyway. The new panel will only cost you $20 to $30 and $10 for 2 pole breakers.
New breaker for this panel will cost you $50 to $60 or more.

 

Yes, the metal conduit goes all the way down to the main panel, so I should be able to tie the ground wire to it.

I have relayed all the information about the outdated Stab-Lok panels and breakers to my in-laws. I think they are leaning towards replacing it soon. Appreciate all the responses, Lambition.


Thank you ibpooks! Interesting information. Yes, I guess my in-laws' concern is that the inspector would for sure see many violations of the code accumulated over the years and won't close the permit without major overhaul of the wiring.

Thank you, Joe! Will check the Connecticut Electric brand.