Wall Oven & Cooktop on the Same Circut

So I am in the process of remodeling my kitchen and I am replacing my old range with a new wall oven and a new cooktop above it. The range was connected via a plug to a 4 pin outlet, which is on a dedicated 50 amp circuit. Obviously this will not accommodate the new 2 appliance set up on the single receptacle. Due to the location and lack of space on the panel, I would much prefer using the existing wiring and either adding a junction box and new outlet or somehow attaching both to the existing outlet . . . though I do not want to jeopardize my safety or do anything that is not code compliant.

From the research that I have done, it seems that putting both on the same circuit is allowable by the 2008 NEC as the cooktop and wall oven are treated as a single appliance, but I am unsure if that has changed since. The wall oven is 3.8 kW @ 240V and the cooktop is 7.9 kW@ 240V.

Is what I am looking to do feasible, safe, code compliant? What would be the best way to achieve the desired results without running a separate circuit from the panel? Any advice would be much appreciated.

 

Welcome to the forums!

48.75A is pushing it on a 50A circuit but, since these are non-continuous loads, you may be able to use the existing wiring and breaker.

 

Manufacturer's instructions trump code. If there is any requirement in either manual calling for a dedicated circuit, or if there is a 'Maximum Fuse/Circuit Rating" of less than 50A on the nameplate of either appliance, then they must be on dedicated circuits.

If there is no requirements by the manufacturer, then you can use 220.55 to factor the demand rating. In your case you multiply the total demand by .65 (since no one load is greater than 8.75kW) so while your total rating is 11.7kW, your demand rating is only 7.6kW. You'd be fine with the 50A breaker.. This is because as Nashkat said ovens and cooktops are non-continuous. Not only are you unlikely to have all burners and all oven elements running at the same time, but each burner/element cycles on and off to maintain its temperature, further lowering the total load that is likely to be present at any given time.

TECHNICALLY you could use a 40a breaker, since the demand load is 32A, and 125% of that exactly 40A, but I think that's cutting it very close and you're likely to get nuisance trips if the right combination of elements are on simultaneously. I would leave the 50A unless you reveal smaller than code wire or there is a max fuse rating of 40A on either appliance.

 

What gage wire. Do you have three conductor plus ground?

 

None of the manuals specifically state that it needs to be an independant circut, just that it recommends a 30A for the range and a 40A for the cooktop.

As for the wiring, there are 3 black stranded copper wires and a ground (one of the black wires is labeled as a neutral). It is labeled S 8 AWG 600v VW.

 

#8 is only good for 40 amps. If there is a 50 amp breaker your circuit was over fused. It needs to be replaced with a 40 amp. A 40 amp circuit is too small for your total needs. You need to run a new service for the oven.

But if this is conduit you can pull #6 wires to replace the #8s, install a 60 amp breaker, and be good to go. From your description it sounds like you do have conduit.