What amp breaker should I use for a 20 Amp electrical oven and a 40 Amp range?
Currently, I have a 6 gauge wire and a 50 Amp breaker, and my current electrical cooktop and electrical oven are both hooked up to this.
I want to replace my current cooktop and oven with a 40 amp electric cooktop (induction-type) and a 20 amp electric oven.
Do I need to update my 50 Amp breaker to be a 60 Amp breaker because the total of the two new appliances is 60 amps? Would the resulting system (6 gauge wire and 60 Amp fuse) be safe for the combined cooktop and oven and within California code?
If helpful, the model and electrical specifications for the two appliances are listed below.
Frigidaire Professional 30'' Induction Cooktop
- Amps @ 240 Volts: 35.0 / 35.1
- Connected Load (kW Rating) @ 240V: 8.4 / 7.3
- Minimum Circuit Required (Amps): 40A
- Power Supply Connection Location: Right Rear
- Voltage Rating: 240V / 208V, 60Hz
Frigidaire Professional 30'' Single Electric Wall Oven
- Amps @ 240 Volts: 20.8 / 18.3
- Connected Load (kW Rating) @ 240V: 5.0 / 3.8
- Minimum Circuit Required (Amps): 20A
- Power Supply Connection Location: Left Rear Bottom
- Voltage Rating: 240V / 208V, 60Hz
Best Answer
Column C
First off you'll notice the text "Column C to be used in all cases except as otherwise permitted in Note 3.)", in the title of table 220.55. This makes it simple. You have 2 appliances, so follow that over in the table, and you'll see 11 in Column C. So there you go, you can just use 11 kW. Done.
11,000 W / 240 V = 45.8333 A
So you'll need a 50 ampere breaker, and wire sized appropriately for the load.
Note 3
Note 3 says:
Perfect, so instead of just using the value from column C you can do math. Let's step through it.
8.4 kW + 5.0 kW = 13.4 kW
Let's check the table again... You have 2 appliances, both between 3 1/2 and 8 3/4 kW. So You'll look at column B, and find 65%.
13.4 kW * 65% = 8.71 kW
8710 W / 240 V = 36.2916 A
So using this method you can use a 40 ampere breaker, and appropriately sized wire. However, keep in mind that if you change the equipment, you'll have to do the calculation again. So while you can use this value, you may have to upgrade the circuit later if you change equipment.
Note 4
I'm not exactly sure how note 4 comes into play, but I think it can be used if this is the only equipment on the branch circuit. Just for fun, let's run through that one too.
You're only concerned with the second half of this note, since you have one counter-mounted cooking unit, and one wall-mounted oven, all supplied by a single branch-circuit, and located in the same room. So you can add the nameplate values, and treat it as a single range.
8.4 kW + 5.0 kW = 13.4 kW
So you can treat the units as a single 13.4 kW range. Check the column C again, this time for a single range. You'll find a value of 8 kW. But wait... The column header says "(Not over 12 kW Rating)". Your range is 13.4 kW. That's bigger than 12 kW. Now you'll have to check note 1
That's easy enough.
13.4 kW - 8 kW = 5.4 kW
Since .4 is not a "major fraction", you can just use 5 kW. So you'll have to add 5% 5 times.
5% * 5 = 0.25
8000 W * 0.25 = 2000 W
8000 W + 2000 W = 10,000 W
That means you'll have to use 10 kW as your demand.
10,000 W / 240 V = 41.666 A
Which means you can use a 50 ampere breaker, and appropriately size wire.