Replies

1. 
   MSA1 | Mar 23, 2009 03:05pm | #1

   Is it a gas cook top or elec? Everytime we've installed seperate units the top was always gas and only needed 120v.

   Off the top of my head I would think no but it would depend on the rating of the two pieces.

    

   Family.....They're always there when they need you.

1. 
   wane | Mar 23, 2009 03:22pm | #2

   Each built in appliance is to have its own circuit.

2. 
   shawncal | Mar 23, 2009 03:22pm | #3

   The would both be electric.  We are interested in trying an induction cooktop, but the options are very limited in induction ranges.  Hence the separate cooktop and oven idea...Shawn

1. 
   BillHartmann | Mar 23, 2009 04:16pm | #4

   Yes, the code specifically allows this. I will quote it later today.But one qualification. You said that it is /3 wiring. Wanted to verify that is was 3 conductor PLUS ground.New circuits, since 1996 NEC, require the 4 wire wiring. It probably depends on the interpretation of the local AHJ if this would be considered new or allow to use the existing 3 wire feeder.The code does clearly call out that existing 3 wire feeders can be used with new equipment..
   William the Geezer, the sequel to Billy the Kid - Shoe

1. 
   shawncal | Mar 23, 2009 08:43pm | #6

   Yes, it is 3 wires plus bare ground wire.Shawn

1. 
   BillHartmann | Mar 23, 2009 10:13pm | #7

   From the 2005 NEC"II. Branch-Circuit Ratings
   210.19 Conductors — Minimum Ampacity and Size
   (A) Branch Circuits Not More Than 600 Volts(3) Household Ranges and Cooking Appliances Branch-circuit conductors supplying household ranges, wall-mounted ovens, counter-mounted cooking units, and other household cooking appliances shall have an ampacity not less than the rating of the branch circuit and not less than the maximum load to be served. For ranges of 8 3/ 4 kW or more rating, the minimum branch-circuit rating shall be 40 amperes.Exception No. 1: Tap conductors supplying electric ranges, wall-mounted electric ovens, and counter-mounted electric cooking units from a 50-ampere branch circuit shall have an ampacity of not less than 20 and shall be sufficient for the load to be served. These tap conductors include any conductors that are a part of the leads supplied with the appliance that are smaller than the branch circuit conductors. The taps shall not be longer than necessary for servicing the appliance."This is from the Handbook. It is not code, but background and explanatory information."Exception No. 1 to 210.19(A)(3) covers factory-installed and field-installed tap
   conductors. A revision to the 2005 Code clarifies that the supply conductors included
   in a factory-installed pigtail are considered to be tap conductors in applying this
   exception. As illustrated in Exhibit 210.21, this exception permits a 20-ampere tap
   conductor from a range, oven, or cooking unit to be connected to a 50-ampere branch
   circuit if the following four conditions are met:
   1. The taps are not longer than necessary to service or permit access to the
   junction box.
   2. The taps to each unit are properly spliced.
   3. The junction box is adjacent to each unit.
   4. The taps are of sufficient size for the load to be served.".
   William the Geezer, the sequel to Billy the Kid - Shoe

2. 
   shawncal | Mar 24, 2009 06:42am | #8

   Thanks, Bill.

   But I'm not clearly understanding this wording.  Does "Exception no. 1" imply that more than one appliance can be connected to the 50a circuit, via "tap conductors"?

   ThanksShawn

3. 
   BillHartmann | Mar 25, 2009 12:24am | #9

   Yes.The classic arrange would be 1 cook top and 1 oven.But it would also include maybe a stove and an additional oven. Or 2 ovens and cook top.But one would have to check the loads on the each item to see if they would work on a total of 50 amps..
   William the Geezer, the sequel to Billy the Kid - Shoe

4. 
   shawncal | Mar 21, 2010 11:15pm | #10

   Bill,

   Yeah, this thread is a year old, but I am FINALLY getting around to this project.  I would like to use an induction cooktop that specifies a 40A circuit, and a separate oven that specifies a 20A circuit.  I have a run of 6/3 wire with ground to the area. 

   The code section you quoted previously states a 50A amp circuit can be shared, but what about a 60A circuit instead?

   Alternately, would it be better to install a 60A subpanel in the kitchen (I have a space where this could be accesible), then run two separate circuits from here to the appliances?

   Any thoughts appreciated.

   Shawn

2. 
   gfretwell | Mar 23, 2009 07:49pm | #5

   The only real answer is in the installation instructions.
   Electrically you only need to be sure the circuit can handle both loads at the same time but there may be a limitation on the maximum size of the branch circuit (breaker) you can attach either to. This would refer to the internal wiring. You need to be sure that if there is an internal fault that the internal wiring will hold until the breaker trips.