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What amp breaker should I use for a 4500 watt electrical oven and 9600 watt induction cooktop?

Currently, I have a 6 gauge wire and a 50 Amp breaker, and my current electrical range is hooked up to this.

I want to replace my current range with induction cooktop and electric oven.

Do I need to update my 50 Amp breaker to be a 60 Amp breaker? I saw some calculation and this table - http://www.naffainc.com/x/CB2/Elect/EHtmFiles/Table%20220-19.htm

BUT my cooktop is more than 8.75 KW so I wonder if I can't connect both on the same electric circuit?

If helpful, the model and electrical specifications for the two appliances are listed below:

Stove - POWER

Rated Current20 A

Max Power Consumption - 4.5 kW

Amperage Rating At 240 - 20 volts

Voltage 208 - 240 V

Induction Electrical Specification

Element Wattage - 5400

Wattage - 9600 watts

Amperage - 40 amperes

Voltage - 240 volts

https://www.bestbuy.com/site/bosch-800-series-36-built-in-electric-induction-cooktop-with-5-elements-and-homeconnect-frameless/6335119.p?skuId=6335119

https://www.cnet.com/products/samsung-nv51t5511ss-oven-built-in-stainless-steel/

Yuvi
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1 Answers1

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Table 220.55 and combining appliances

Since you're replacing a range with a cooktop+oven as separates, we start with NEC Table 220.55 Note 4:

  1. Branch-Circuit Load. It shall be permissible to calculate the branch-circuit load for one range in accordance with Table 220.55. The branch-circuit load for one wall-mounted oven or one counter-mounted cooking unit shall be the nameplate rating of the appliance. The branch-circuit load for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch circuit and located in the same room, shall be calculated by adding the nameplate rating of the individual appliances and treating this total as equivalent to one range.

As a result, we can treat your new setup as equivalent to a 14.1kW range. We then use the Note 1 rule for ranges over 12kW:

  1. Over 12 kW through 27 kW ranges all of same rating. For ranges individually rated more than 12 kW but not more than 27 kW, the maximum demand in Column C shall be increased 5 percent for each additional kilowatt of rating or major fraction thereof by which the rating of individual ranges exceeds 12 kW.

Given that a single 12kW range is treated as an 8kW load (first entry in Column C of the table), we have at most a 15% bump over that 8kW, or 9.2kW of load from your new appliances. This is no sweat whatsoever for a 50A circuit on 6AWG wire, as it comes out to just over 38A at 240VAC.

ThreePhaseEel
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  • This is such a "you" question :) – Harper - Reinstate Monica Sep 04 '21 at 18:28
  • Thanks for the answer @ThreePhaseEel. One thing that I did not understand, is why we go to note 1 and not note 2 as the cooktop and the stove has different ratings? "Over 83/4 kW through 27 kW ranges of unequal ratings" – Yuvi Sep 04 '21 at 22:46
  • @Yuvi -- we thank people around here by upvoting and accepting their answers :) – ThreePhaseEel Sep 04 '21 at 22:48
  • Also, I am not sure I understand where "Given that a single 12kW range is treated as an 8kW load" came from. From what I can see in the table, it is written "Column C, Maximum Demand (kW) (See Notes) (Not over 12 kW Rating)" and mine is over 12kW. What am I missing? – Yuvi Sep 04 '21 at 22:52
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    @Yuvi -- the Note 1 procedure (quoted in the answer) starts with that number from the first row of Column C and adds on to it – ThreePhaseEel Sep 04 '21 at 23:06
  • And what is "not over 12 kW rating" referring too in Column C header? – Yuvi Sep 04 '21 at 23:15
  • @Yuvi -- the nameplate rating of the range load, or in your case, the sum of the nameplate ratings of your appliances since you have separate appliances sharing a branch circuit – ThreePhaseEel Sep 04 '21 at 23:22
  • So in that case, the sum is more than 12kW but the header says "Not over 12 kW Rating". I am missing something? – Yuvi Sep 04 '21 at 23:35
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    @Yuvi -- what you're missing is that the Note 1 procedure says to add to the value from Column C :) – ThreePhaseEel Sep 04 '21 at 23:53