DIY Home Improvement Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
125 Posts
Discussion Starter · #1 ·
I have seen a number of these posts when I search but I couldn't find my specific situation.

I am remodeling my kitchen. I'm keeping the oven/microwave combo as well as the electric cooktop, however I need to remove then reinstall again after cabinets. When removing I found something I hadn't seen before and wanted to make sure it was ok. The oven and range are on the same 50 amp 240 V circuit. The feeder circuit coming from the breaker looks like 6 gauge aluminum. It goes to my oven, and cooktop. From my research i think the wire is SE wire. It has 2 insulated wires, black, and black with a red stripe and it has a bunch of bare aluminum strands that are twisted together in the junction box. This was wired to my cooktop which has 4 wires, red, black, white and bare copper in a metal junction box. The cooktop white and bare copper both connected to stranded bare aluminum, which was also connected to the metal box. The red went to the black with red stripe, and black to black.

From what I read, using bare ground of NM cable as the neutral is a no go, but everything seems to imply that with SE cable it is ok to connect both ground and neutral from the appliance to the bare strands. I want to confirm this before hooking everything back up again. FWIW, house was built in 1989, and at least the oven/microwave is newer than the house. I think the cooktop is as well. Am I ok hooking everything back up the same or what are my options?

Thanks,
Richard
 

·
Super Moderator
Joined
·
16,917 Posts
You are correct that the bare from NM was not to be used as a neutral, but the bare in SE cable was allowed.

I would run new grounded circuits for both if you could.
 

·
Red Seal Electrician
Joined
·
1,037 Posts
I don't know if current codes allow a 3-way 'tap' like that for 3 discrete appliances.


My used double wall-oven specified a 30A/240V circuit for each unit, plus a 15A/120V circuit for the controls. Maybe check your oven's manual. A cooktop or microwave would each be an extra circuit also.



I might put a small subpanel on the end of that #6, and run a fresh ground back to main.
 

·
Registered
Joined
·
5,678 Posts
When removing I found something I hadn't seen before and wanted to make sure it was ok. The oven and range are on the same 50 amp 240 V circuit. The feeder circuit coming from the breaker looks like 6 gauge aluminum.
Oven and cooktop sharing a circuit is OK.
Aluminum wire is OK if it’s AA-8000 alloy (no AA-1350 allowed).
6 AWG aluminum is OK for 50A if it’s a cable or wire type allowed to run at 75C temperature (so definitely not NM or UF cable).





It goes to my oven, and cooktop. From my research i think the wire is SE wire. It has 2 insulated wires, black, and black with a red stripe and it has a bunch of bare aluminum strands that are twisted together in the junction box.

From what I read, using bare ground of NM cable as the neutral is a no go, but everything seems to imply that with SE cable it is ok
WAS okay in 1989. Certainly is not OK now. Other than that, your analysis is spot-on.

Notice how you are assuming that you are entitled to “grandfathering” on the wiring, i.e. to continue using the old wiring even though it is deficient by modern standards. Remodels do not work that way. A remodel wipes out grandfathering and requires all the kitchen electrical to be brought up to Code, including dedicated circuits for every darned thing.

You can throw yourself at the mercy of your AHJ and ask permission to keep the 6/2 SE, and just retrofit a #10 ground wire. However the AHJ might not like that if the old cable is AA-1350, which needs to go.

Otherwise you’ll need to pull appropriate modern w/ground cabling. And you’ll need a wire upsize (either to #6 Cu or #4 Al) unless you use a 75C wire type such as THHN in conduit. From the AHJ’s perspective, you need to pull a bunch of new circuits *anyway* so what’s one more?


to connect both ground and neutral from the appliance to the bare strands.... Am I ok hooking everything back up the same or what are my options?
Aside from being illegal, you don’t want that for the reason it’s illegal. That style of connection is called “bootlegging ground”. The appliance industry lobbied to get this allowed as a special exception for dryers and ranges, because they feared huge loss of appliance sales if people had to rewire.

If the neutral wire gets loose, normally, that causes neutral to float at a hot voltage. That’s why we put insulation on it lol, which makes that event a nothingburger. But if you have bootlegged ground, now the ground also floats at the hot voltage! So the thing you wanted to render safe is now rendered dangerous! And yeah, this has killed people.
 

·
Super Moderator
Joined
·
16,917 Posts
An existing 3 wire circuit wired with SE is allowed to remain, however I would advise replacement with a 4 wire circuit.
 

·
Registered
Joined
·
125 Posts
Discussion Starter · #6 · (Edited)
I agree running new wire would be ideal but my panel is in a hard to get to spot. I'd be ripping my whole house apart, to do it. I wasn't planning on an inspection since I'm not adding anything new and wasn't planning on running any new wires pending the outcome of this. I'm just removing then re-installing the existing appliances in new cabinets. FWIW, when I said remodeling, I'm getting new cabinets and counters.

Jim Port says SE cable is allowed though not ideal obviously, seharper is saying it isn't allowed and is dangerous. I don't want something that is going to kill me obviously. Which is it? Why was/is SE allowed when NM wasn't? I assume it had to have been safer having all the strands seperated in the cable?

Thanks,

Richard

Edit: From my reading, AA-8000 was required by code prior to my house being built so I'm assuming that what I have. Is there a way to tell for sure without seeing whats on the sheathing? There isn't much visible in either connection location nor the panel.

I just thought of something else. I assume this isn't allowed but figured I'd check. I have a 50A hot tub circuit that is in proximity to the two connections in the kitchen. It is wired with 6/3 copper. Could I break into that circuit and use that ground so I don't need to pull something all the way back to the panel, then wire the neutral to the bare aluminum, and ground to the new ground run from the hot tub circuit?

Edit 2: If I'm able to use the hot tub ground, I could also pull a ground from my hot tub panel to the oven and cooktop boxes. I don't know if connecting in the hot tub panel is better, worse, or no different than a junction box under my house. Probably would be easier for me though.
 

·
Registered
Joined
·
5,678 Posts
It’s dangerous either way. It’s allowed *If* two things are true: First the circuit doesn’t need to be extended, and second the AHJ agrees to allow grandfathering even though it’s a remodel.

Inspections aren’t something you *request*, they are *mandatory* and part of the permitting process. You are choosing not to pull a permit for this remodel. I don’t know what’s up with that. I hope it’s not because of unawareness of the need, rules and (severe) consequences regarding the pulling of permits.

Like I say, what surprises me is that you aren’t already having to add circuits to meet the NEC 2014 requirements for kitchen circuits, so one more cable in a significant bundle isn’t much. Even if you don’t have to pull a permit, that is not license to do whatever you want; you still have to follow Code.

SE cable isn’t dangerous, and the strands being separated isn’t the issue. What’s dangerous is a 3-wire range or dryer connection. The problem is, it is functionally bootlegging ground off the neutral wire. If the neutral wire has a contact problem at either end, then neutral and ground are connected at the range, current is unable to return on neutral, and so the voltage at the neutral rises to 120V. (That’s why we insulate neutral wires, to hedge against that). Now, if you have bootlegged ground from neutral, chassis ground is also floated to 120V. Now your oven chassis is energized at 120V when it’s supposed to be grounded.

If it is legal for you to continue the SE in service, you can render it safe by doing TWO things together: a) Use a GFCI breaker to feed the range. AND b) reconfigure the range wiring so it is set up for 4-wire (bootlegging removed) but ground is simply unconnected. And if a socket is involved, that socket gets a label “GFCI Protected / No Equipment Ground”.
 

·
Registered
Joined
·
125 Posts
Discussion Starter · #8 ·
I never thought it would be required to add circuits to bring up electrical code if I wasn't opening any walls or moving anything just swapping cabinets. The locations of appliances and everything is staying the same.

Regardless, if I determine it is legal to use the 3 wire, I can just install a 50 amp GFCI in the panel and should NOT connect the grounds of the appliances? The manual for the cooktop just says to wire the ground and white together to the incoming ground, there is nothing mentioned about them being internally bonded or anything. The oven/micro combo says for 3 wire the neutral and ground should be crimped together which they aren't so it seems like it is set up for 4 wire install. When I removed the ground and neutral of both appliances were both connected with a wire nut to the bare aluminum. I would install this time without connecting the ground.

The problem I see is if the ground has to be disconnected, the bround from the appliances is bare copper in metal sheathed cable connected to a metal junction box. The bare aluminum is going to be touching that as well, and probably be in contact with the bare copper in the junction box as well even if they aren't physically connected.
 

·
Registered
Joined
·
125 Posts
Discussion Starter · #10 ·
I have been reading this post:
https://www.diychatroom.com/f18/borrowing-ground-another-circuit-450370/

From that it seems like it is OK to pull a ground off a different circuit. There seems to be a caveat that it must come from a circuit that originates in the same panel. Would this be the case if I connected ground in my spa panel which is connected to my main panel with the oven/range circuit? What if I break into the circuit between the spa panel and the main panel? I don't know why that would be any different however. Whether I do it at point a or point be they are still connected to the same circuit.

This wouldn't affect my GFCI breaker in the spa panel correct?

If that is true, I should be able to pull a ground from my spa panel, run it to the oven/micro combo, and then to the cooktop, connect all the grounds, the neutrals to the SE bare aluminum, and black to black and red to red and be all good unless I'm missing something, correct?

Additionally, I have some 6/3 that I could pull between the oven and cooktop, but the SE aluminum cable would still go from the cooktop to the panel, any issues pulling the ground to the oven, SE would stay from the oven to the panel, and 6/3 would go oven to the cooktop? Not sure if there is any difference or benefit to this situation.

Thank you for all the input,

Richard
 

·
Registered
Joined
·
5,678 Posts
I got confused because you said “remodel”. Whether the work you’re doing qualifies as a remodel for NEC purposes, is best hashed out with the AHJ who issued the permit for the work.

The GFCI is a fine plan, however, if you do this, you must do a 4-wire style connection with ground intentionally dead-ended... avoid at all costs tying neutral to ground at the appliances or it will partially defeat the GFCI protection.

Or, your “retrofit ground” plam is also a winner. I’m not sure whether you’re allowed to tap feeder wire to another panel.
 

·
Registered
Joined
·
125 Posts
Discussion Starter · #13 ·
Reading your post again, I'm a bit confused about when you say intentionally dead-ended. Do you mean just wire nut the ground?

Then also avoid at all costs tying neutral to ground at the appliance, but if both ground and neutral SE are bare wire won't they most likely be shorted in a metal box with metal conduit, even if they aren't physically wire nutted together?

Thanks,

Richard
 

·
Super Moderator
Joined
·
16,917 Posts
The neutral cannot be bare in metallic conduit. It would create a shock hazard.
 

·
Registered
Joined
·
125 Posts
Discussion Starter · #15 ·
The SE isn't in metal conduit, the metal conduit is the whip from the appliances that has insulated neutral and bare copper ground. It is connected to the SE in a metal box for the cooktop. Plastic box with metal cover attached to the whip for the oven.
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top