That could be a split bus panel, meaning that there are two sets of power distribution buses. It used to be allowed by something called the "6 handle rule" (which allowed up to six of them in a service panel) back when circuit breakers cost a small fortune.
They were wired like this:
And might look like this:
Note the gap in the breaker buses at center where there are no breakers, but you can see heavy black wires connecting to the right end of the secondary buses.
The cables from the meter connect at right (which would conventionally be the top of the panel) and feeds the six double breakers. Five of them feed directly to heavy loads: range, water heater, dryer, baseboard heaters, etc. The top-left double ganged breaker feeds the second bus in the left half of the photo.
In this configuration, any circuit fed from the lower bus would be shut off if either its own breaker were switched off, or the feed breaker—which also shuts off almost everything in the building.
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:
- Over 1 3⁄4 kW through 8 3⁄4 kW. In lieu of the method provided in Column C, it shall be permissible to add the nameplate ratings of all household
cooking appliances rated more than 1 3⁄4 kW but not more than 8 3⁄4 kW and multiply the sum by the demand factors specified in Column A or
Column B for the given number of appliances. Where the rating of cooking appliances falls under both Column A and Column B, the demand
factors for each column shall be applied to the appliances for that column, and the results added together.
Perfect, so instead of just using the value from column C you can do math. Let's step through it.
...it shall be permissible to add the nameplate ratings of all household
cooking appliances rated more than 1 3⁄4 kW but not more than 8 3⁄4 kW...
8.4 kW + 5.0 kW = 13.4 kW
...and multiply the sum by the demand factors specified in Column A or
Column B for the given number of appliances...
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.
- 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.
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
- 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.
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.
Best Answer
No, you cannot tap off of a 40 amp circuit for receptacle circuits.
According to the National Electrical Code Article 210.21(B) and Table 210.21(B)(3) Receptacles connected to a 40 amp circuit would have to be rated 40 or 50 amps. Kinda tough to plug your toaster in to those.
Here are two other places in the National Electrical Code that cover kitchen branch circuits.
The exception below allows you to power cooking equipment from a 50 amp branch circuit but not receptacles from a 40.
The Code requires a minimum of 2 20 amp Small-Appliance to serve the counter tops in the kitchen. The pertinent article is below:
Kitchen island counters require enough receptacles so no part of the counter is more than 24 inches from a receptacle.
So, you need some receptacles on the island. And you can't feed them from taps off of the 40 amp circuit. However, you could put a sub-panel on the island as Tyson points out. The problem with this idea is the cooktop takes the entire capacity of your sub-panel.
The best thing to do would be to run #12 AWG wire for one or more circuits to the island.
Good luck!