2

I will be remodeling kitchen and replacing gas oven/range with induction cooktop (220V, 20 amp) + electric wall oven (also 240V, 30amp)

I don't know much about electricity and need help to determine whether my electric panel will support it.

Some other notes:

  1. I have ac/heat unit inside the apartment as well as water heater and both appear on the panel.
  2. I also have pictures without front cover but I can't seem to upload more than one picture. Please let me know if you prefer to see inside of the panel
  3. this panel is Siemens is G1224L1125(CU) and "Main Lug/Main Breaker Kit table on the panel label has the following:
    100 AMP Main breaker
    125 AMP Main breaker
    100-125 Main Lug

Also, as per my comment below, I can remove jacuzzi and replace it with shower. Please let me know if that would help a lot or if I can accomplish what I need without removing it.

panel deadfront panel with deadfront off panel label

  • That panel appears to be too full to fit in two additional double pole breakers. – Dan D. Aug 4 '16 at 3:02
  • 2
    @DanD. He can put both the cooktop and the oven on the same circuit -- there's just enough room in the panel for this to work, although it involves moving the rooms 1-2 lights/outlets circuit and replacing the current double-stuff that feeds the bathroom GFCI – ThreePhaseEel Aug 4 '16 at 4:12
  • 1
    Can you get us the square footage of your apartment and the nameplate wattage ratings of your proposed cooktop and oven as well as your current water heater, AC/heater, and Jacuzzi? Also, I take it this is the only subpanel in your apartment (i.e. there are no breakers anywhere else that control anything else?) Also, can you upload the other pictures to imgur and post them in a comment here so we can edit them in? – ThreePhaseEel Aug 4 '16 at 4:15
  • 1
    My apologies for late response, been busy day today. Here's the picture of inside of the panel: imgur.com/a/5rJ8K. Additionally if it would make it easier, I'm thinking about replacing Jacuzzi with tiled shower so that can breaker can go away. Please make further suggestions. – P. D. Aug 5 '16 at 0:51
  • 1
    I still need the square footage of your apartment + the nameplate wattage/amperage numbers from the current water heater, heat/aircon, and Jacuzzi as well as the cooktop and oven you plan to put in. – ThreePhaseEel Aug 5 '16 at 4:32
2

You can do this, but it will fill up your feeder!

Assuming that:

  1. You are removing the Jacuzzi and disabling its associated dedicated circuit
  2. That the "GFI Kitchen", "Wall Outlet", "Microwave", and "Dishwasher" circuits are all kitchen Small Appliance Branch Circuits (SABCs)
  3. Your condo is fed with 120/240V split phase (some high-rise condos are fed with 2 phases of a 208Y/120 3 phase service instead)
  4. Your feeder is 2AWG XHHW-2 aluminum, limited to 90A and 75°C by its terminations, and
  5. You have a 90A feeder breaker protecting the feeder and panel

we can apply the multiunit feeder calculation methods from the Code (Art. 220 Part II) (albeit not the optional simplified calculations from Part III, as we are assuming a 90A feeder here which makes that method inapplicable) to your current configuration to get the following numbers:

  • 1300sf * 3VA/sf = 3900 VA for lighting and general receptacle loads
  • 5 SABCs (4 kitchen, 1 laundry) * 1500VA/SABC = 7500VA for small appliances
  • Your water heater at its 4500VA nameplate load
  • Your A/C at 14.5 combined Full Load Amps at 230VAC = 3335VA (the combustion blower load can be excluded as it doesn't run when the rest of the motor loads are engaged)

For the lighting and receptacle loads, we get 11.4kVA which then gets a 35% demand factor for all load past the first 3kVA to yield 5940VA. From that, we then add the 4.5kVA water heater and the 3335VA A/C to yield a total feeder load of 13.78kVA, or 57A at 240VAC. This leaves just enough room for the 8kVA (or 33A @ 240VAC) range load from Column C of table 220.55, using note 4 to treat the cooktop and oven combination as a single range load of not over 12kVA nameplate.

The resulting breaker switcheroo -- if you feel uncomfortable with this, feel free to ask your friendly local electrician to do this for you

  1. Get a Siemens QT1520 breaker -- you'll need this to get rid of that single pole 15A breaker
  2. Get a Siemens QP250 breaker for the new circuit
  3. Run the cable for the new kitchen appliances and hook them up, but don't feed it into the panel yet. Let us (or your friendly local electrician) know if you need help with this
  4. Have the power turned off to your unit at the feeder/main breaker
  5. Get the front off the panel
  6. Remove the existing breaker from the slot labeled "Jacuzzi" and "GFI Kitchen". Take the upper wire off (this went to the Jacuzzi) and put a wirenut on the end to cap it off. Take the lower wire off and flag it with electrical tape so that you can find it to put it on the correct half of the new double-stuff breaker. Set this breaker aside.
  7. Remove the existing breaker from the slot labeled "Rooms 1-2 Lights-Outlets". Take the wire off, but do not flag it or cap it. Set this breaker aside as well.
  8. Move the two breakers that were above the removed 15A breaker down a slot in the panel -- there should be two open slots at the top left of the panel once you are done with this step.
  9. Install the QT1520 in the open slot in the top right. Attach the flagged wire to the 20A (upper, if the photo I have seen is any indication) slot in the breaker. Attach the unflagged wire to the 15A (lower, again based on the photo I have seen) slot in the breaker.
  10. Install the QP250 in the two open slots in the top left.
  11. Run the cable for the new kitchen circuit into the panel itself and attach the black and red wires (hots) to the QP250 breaker you just installed.
  12. Attach the neutral from the new cable to the left-side neutral bar on your panel.
  13. Attach the ground from the new cable to the ground bar on your panel (I suspect it's on the far left side, outside of view of the photo of the panel insides you have posted).
  14. Button the panel back up.
  15. Turn the power to your unit back on.
  • Wow - this is no doubt one of the best online answer I've ever received across many websites/topics! Can't be thankful enough. I will probably hire electrician to do the work (unless you're in my area and interested in taking on this assignment) but for step #3 I'd like a quick explanation as I don't fully understand it.Are you asking to run a single cable to connect both induction cooktop and elec. oven to it (again, those are 2 separate 220v units so I want reassurance it is safe todo so)? 1 more thing, forgot to mention I'm notgoing to have microwave- not sure if that would change much – P. D. Aug 16 '16 at 22:21
  • You can run a single cable or two cables that join at the panel -- it's a single circuit either way, as I understand it, though. (Otherwise, you wouldn't able to treat the cooktop+oven combo as a single range load.) – ThreePhaseEel Aug 16 '16 at 22:27
  • Last question: do you think I have a chance to pass the inspection if electrician follows your recommendation? You've provided a lot of calculations to back up your recommendation but I'm little concerned inspector might not even look at that but instead focuses on how almost-full this panel is and refuses to accept changes you're recommending. Any advise on whether I should worry about it? This is condo unit so I don't have a choice but to hire electrician and stay up to the code/pass inspection. Thanks. – P. D. Aug 18 '16 at 3:20
  • @P.D. if the inspector refuses to go by NEC Art. 220, then you have bigger issues – ThreePhaseEel May 24 '19 at 11:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.