I am a newbie, so please bear with me a little.

I have two circuits coming from the electrical panel that are 240v each, into my kitchen. One of those is used by a microwave/oven combo and is working. The other is marked as electric cooktop but we do not use it as we have gas cooktop. There is a box under the gas cooktop, and when I use my multimeter, it shows no power. There is no junction box or anything else on this line, it is straight from the panel to this box. The panel shows a 240v, 50amp line.

I have not yet opened the panel, but I am guessing that the wires inside the panel are not connected. I plan to open and check that today, but wanted to ask if there is anything else I should be checking?

The second question is; if I find unconnected wires in the panel then can I just connect the circuit? Or there is a way to check how much the load is on the existing before plugging in the line.


Box under the cooktop

#11 and #13 are combined

Two wires coming from panel and going to kitchen. Can't find the gauge.

Inventory of the breakers in the panel

  • Just confirmed that this is 8 gauge cable. So even if the panel shows 50 amps, the max I can run is a 40amps, which will work for me.
    – adadevil
    Jun 8, 2022 at 12:29
  • How exactly did you use your multimeter to confirm that the wires have no power?
    – LShaver
    Jun 8, 2022 at 12:45
  • 1
    @LShaver, I put the meter at 600V AC, and tested once with hot and neural and then with hot and ground. Then I tried all possible combinations, but everything read a zero. I also tried with 600V DC but this anyway should not have worked.
    – adadevil
    Jun 8, 2022 at 13:52
  • What is your new load? You didn't mention getting an electric range. Breakers must be matched to the load. Jun 8, 2022 at 17:22

2 Answers 2


With the pictures it looks like they left the bottom box wires where they were and capped/nutted(the red thingies) them at each end.

They then ran a new circuit for the microwave and used the breaker for it.

You will need to install a new 50 amp 40 amp breaker (updated due to new information) in the panel to use the circuit for the bottom box. That size of circuit is for one device only.

Need a breaker and circuit for each device.

With the new comment that the wire is only 8 gauge then should only use a 40 amp breaker to power that circuit.

  • The op stated 8 awg wire prior to this answer but your comments point to a lack of understanding how the tables work.
    – Ed Beal
    Jun 8, 2022 at 13:16
  • Thanks @crip659! I opened the panel and they took the line and capped it on both ends. The existing 50amps circuit is feeding another sub-panel and so I will need a new breaker.
    – adadevil
    Jun 8, 2022 at 13:43
  • 1
    @EdBeal Did not see or the comment did not show when I made the answer. I made the very wrong assumption that a 50 amp breaker would be wired correctly. Have edited my answer with the new information provided. Possible they upgraded the breaker with the new circuit also. Thank you.
    – crip659
    Jun 8, 2022 at 13:43
  • 1
    Ok but a 40 amp circuit can have a 40 OR 50 amp receptacle by code, so it is code compliant to have a 50 amp receptacle on #8 copper
    – Ed Beal
    Jun 8, 2022 at 16:07

Your breaker needs to match the load!

You didn't mention what the load is. If the load is general 15/20A receptacles, you need to change the breaker to 20A. (because kitchen receptacle circuits must be 20A, and 15A receptacles are allowed on 20A breakers, that is the only exception).

If you have an oven whose breaker says "30A" then the breaker must be 30A.


The most you can get out of that #8 copper NM-B will be 40A. If I am incorrect and the cable is a type other than NM or UF, then you may be able to get 50A out of that, but only if it's going to an appliance which is asking for a 50A breaker. Note that since 40A receptacles are impossible (not enough pin arrangements available), 40A circuits use 50A receptacles. This is not an exception to a rule. 40A appliances need 40A breakers.

That box is too small to do anything with

That "Octagon box" doesn't have enough cubic inches to splice anything to it. You need

  • 3 cubic inches for each #8 wire
  • 2.5 cubic inches for each #10 wire
  • 2.25 cubic inches for each #12 wire
  • Grounds are "4 for the price of 1" based on the largest. Expect #10 ground with #8 conductors.
  • I assume there will be no receptacles, but each yoke (receptacle assembly) needs cubic inches same as 2 "wires" (the largest size attached to it).

So if you are tying the #8 cable to two 12/2 cables, you have 3x#8 (9 c.i.), 4x#12 (9 c.i.) and 1x#10 (2.5 c.i.) for ground. That is 20.5 cubic inches.

If you attach the #8 cable direct to a 40A receptacle, you need 3x#8 (9 c.i.), 2x#8 (6 c.i. for the receptacle) and 1x#10 (2.5 c.i.) for the ground. That is 17.5 cubic inches.

How do you obtain the cubic inches you need? The simplest way is to stack on an octagon "extension box" which is the same shape/size of octagon box with an open back. If you need a low-profile solution, change the octagon box to a 4x4x1-1/2" box (same thickness slightly wider dimension) which is 21 cubic inches, possibly with a blank domed cover (1/2") to gain 6 more cubes. If you need more still, go to a 4-11/16" square box (42 cubic inches).

The box needs a cover.

The ground wire must go to the metal box.

There is a #10 ground wire coming in with this cable. It must be attached to the metal box FIRST, do not attach it to a receptacle or other cable and bypass the metal box. You are welcome to use 6" of #10 wire as a "pigtail" to the metal box, then join that to the other with extra-large wire nuts.

There will be a hole in the back of the box tapped for a (screw size) #10-32 machine screw aka bolt. They actually make special green screws made for this purpose, but plain old silver ones will do. Do not use the wrong thread pitch and do not use a sheet metal screw.

Pigtails do not count when figuring cubic inches. So the #10 ground pigtail can be ignored.

Panel numbering is incorrect

Someone who doesn't know what they're doing went down the sides of the panel and numbered all the breakers. They were already numbered (stamped in the metal) and the Sharpie is wrong. They should be numbered 1A, 1B, 3A, 3B, 5A, 5C down the left side for instance. That is a big deal because of phasing.


The breakers in actual space 1-2 are on phase L1.
The breakers in actual space 3-4 are on phase L2.
The breakers in actual space 5-6 are on phase L1.
The breakers in actual space 7-8 are on phase L2.

GE's are weird in that they let you stack 2 thin breakers in one space. But with great power comes great responsibility.

The amateur numbering destroys this important information. 240V breakers span 2 spaces (e.g. the 30A breaker in 1B and 3A) which gives it access to 240V. That is essential. Especially for MWBC circuits, where mis-phasing it could cause it to fail "silent but deadly".

If you'll be placing a 2-pole breaker, or moving breakers around to fit a 2-pole breaker, you need to know about that stuff, particularly MWBCs, as it's very easy to get those wrong in a GE panel.

  • 1
    You can remove the numbering with rubbing alcohol, get the higher proof version. Jun 8, 2022 at 19:11
  • Thanks @Harper! Lot of good information. The actual load is going to be a EV charging port. So just a single 40A 240V outlet is what I needed. I was hoping to redirect one of the unused lines to garage. However, this unused line is capped at both ends, and the actual 50A breaker is used for feeding another sun-panel. This means I need a new breaker in the panel, but there is no space in the panel anymore. Installing a new sub-panel is probably beyond my DIY skills.
    – adadevil
    Jun 9, 2022 at 11:42
  • @adadevil what do all the other breakers do? Your project will be advanced far by knowing that. (as in, a careful inventory may reveal 3 breakers that are unused, "that was easy") Jun 9, 2022 at 20:23
  • @Harper-ReinstateUkraine I just attached picture on the inventory. Is this what you meant? It seem all but one is redundant. I am not sure why would I have a 20amps on the slot #20 for Microwave when I have another dedicated circuit for Oven+M/W. Is there a way to consolidate any of these?
    – adadevil
    Jun 9, 2022 at 23:43
  • Yeah, you really need to chase them all down to see what they actually do. And figure out if there's stuff you don't really need. (check Code to make sure any factor-downs are legal, for instance 20A kitchen, bathroom and laundry circuits need to be dedicated.) Jun 10, 2022 at 7:08

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