This is my breaker box; I'm concerned about not having enough space to accommodate an electric range which requires 240v 40A. My box has tandem circuits, although I'm not sure if consolidating additional breakers will free up 2 slots, which is what I need.

Is it possible to extend the poles to create more slots? Panel door has cut-outs for additional breakers, but the concern is overloading the system.

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  • Is putting a bigger panel (slots-wise) in an option? Also, is this a subpanel or your only panel? Jun 24, 2017 at 3:52
  • It's my only panel. If I need to install a larger panel to replace this one, I'm fine with that.
    – raffian
    Jun 24, 2017 at 4:03
  • head explodes But it's wired like a subpanel. Is this a tenant unit? Do you have your own electric meter? Where is the main breaker? Looks like the whole panel is 50-60A tops. Jun 24, 2017 at 4:07
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    How big is the feeder to this panel amps-wise, how many square feet is your apartment, how many kitchen small appliance circuits do you have, and is your HVAC fed from this panel? Jun 24, 2017 at 5:08
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    ThreePhaseEel has a great quesiton - how large are those feeder wires? They look way too small to carry 100A. Jun 24, 2017 at 12:41

2 Answers 2


First, you say your service is 100A, but those "main supply" wires look awfully small for 100A. They look a lot like #6 copper, which is only good for 60A tops. I would make sure the wires are appropriate for the main breaker. If they are inadequate, either upsize the wires or downsize the main breaker.

This ... I hesitate to use the word "service panel" ... is still supported. Bryant was bought by Cutler Hammer, in turn bought by Eaton, and became Eaton's "BR" service panel line. "BR", Bryant, get it?

Yes, you can get a "quadplex" double-stuff which fits in two spaces and supplies two 240V circuits. This quadplex will have proper and internal handle-ties, NOT A FLIPPIN' NAIL. For instance this quadplex includes a 2-pole 40A and a 2-pole 20A. It would replace the breakers with the nail.

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That breaker isn't just two twin breakers bolted together. It is purpose-built to be a quad. Internally there is a mechanism to assure both sides of the circuit trip together if either overloads (common trip). That works with or without the goofy looking handle-ties. The handle-ties are just UL listed versions of a nail; they are there to provide common maintenance shut-off. With a nail (or listed handle-tie), common trip is not guaranteed.

You cannot add any more breaker spaces to this panel. The cover has additional knockouts, but there'd be nothing under the knockouts. This is an 8-space/16 circuit panel, you are using 14 and have only 2 more possible.

After this you can add 2 more 1-pole circuits or 1 more 2-pole circuit and your panel is wedged solid. You might want to think about a bigger panel at some point. Get a panel so large that you never, ever need to use double-stuff breakers. (because increasingly, they are requiring GFCI and AFCI breakers, and those don't come in double-stuff.) You need 14 now, 24 is borderline too small, I would go at least 30, even 42.

You don't need to deprecate that panel, you could add a larger panel as a subpanel fed by a large breaker.

You could stay in "BR" panels if you really wanted to, it is still common and supported, though a bit on the cheap side. Siemens is commercial grade (so are CH and QO, but their breakers are rather expensive).

  • I think I understand; the two breakers (with the flippin' nail) use 2 pols for 20A/240v. You're saying replace those two slots with a single quadplex; the 20A half of the quadplex powers whatever was connected to the breakers before, and the remaining half of the quadplex is 40A 240v, exactly what I need for the range; Is that accurate?
    – raffian
    Jun 24, 2017 at 4:25
  • @raffian Yes, and both halves (inner two and outer two) both are 240V. But it's more than that: they do not rely on that weird piece of metal for common trip, they have an internal mechanism for that. The weird piece of metal is used for maintenance shut-off only. That's the trouble with a nail (or even a listed handle-tie): does not guarantee common trip. Jun 24, 2017 at 5:11
  • I inherited the nail when I purchased the unit; I would never put metal near a breaker box, much less a nail connecting two breakers; seriously, whoever did that has guts or a death wish! :-D
    – raffian
    Jun 24, 2017 at 14:13
  • Regarding 100A, I'm no electrician, I only mentioned it because it was on the panel,
    – raffian
    Jun 24, 2017 at 14:19

I agree with @Harper completely, but I keep looking at you pictures and I am trying to figure out what this structure was before it was a dwelling. I am looking at my 1965 NEC and even that required a minimum 100A service, 2 - 20A small appliance circuits, a washer, a dryer, and a range receptacle, along with general purpose receptacles and lighting circuits. Throw in AC and heating and a water heater and you don't have enough circuit space. Also the feeder @Harper pointed out, the minimum size would be a derated 100A feed of a #4 conductor. So there should be a Main Breaker or Fused Disconnect somewhere. Can you tell us what size it is?

Also I try not to advise anyone from using small tandem breakers on anything except 15A and 20A circuits. If you look at these breakers you will see you have the same contact size for the buss for a 70A two pole breaker as a 15A two pole. So large heavily used amperages have a tendencies to burn out the panel buss and breaker at their point of contact over time.

My advice is to forget trying to add circuits to this panel and do an upgrade and at least bring it up to NEC code standards.

  • It was always an apartment building, built in 1940. I don't have that many appliances; electric range, standard refrigerator, microwave, very small wine cooler, 2 window ACs, LED TV, PC + monitor, and the rest is lighting for a two 2 bedroom apartment. No washer/dryer/hot water heater, etc., in the apartment.
    – raffian
    Jun 25, 2017 at 3:27
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    1940 explains a lot, but let's not detract from the NEC requirements the major difference between a single family and an apartment dwelling is the laundry and water heater. You didn't have AC's, wine coolers, TV's of any kind, microwave, and even refrigerators were just coming in as standard equipment . Also its apparent that the design in the 1940's only allowed for a gas range in lieu of electric. The last point I need to make is that an electrical system's life is estimated at 60 years. So I would go from "recommend" to "it needs" to be upgraded. Jun 25, 2017 at 14:17
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    For those who are wondering how I got to a 60 year life. Research shows that a properly installed system will last 30 years without major malfunctions. The next 30 years the system will experience a 50% failure of all electrical components. So half life thirty years, total life expectancy of a normal electrical system 60. Remember this is statistical data not real life. Jun 25, 2017 at 14:20
  • Thank you, sir; I will inquire with my electrician on the potential of upgrading the panel.
    – raffian
    Jun 25, 2017 at 14:41

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