cooktop / oven

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Where in the code does it state that the branch circuit for a cooktop / oven for new construction has to have 4 wires (2 hots, 1 neutral, and 1 ground wire)? Thanks.
 
Re: cooktop / oven

If there is no need for a neutral the NEC doesn't require one for this.

But what you are looking for can be found in 250.140

Roger
 
Re: cooktop / oven

Originally posted by roger:
If there is no need for a neutral the NEC doesn't require one for this.

Roger
wont you allways have a neutral for the low settings on a cooktop appliance?
 
Re: cooktop / oven

wont you allways have a neutral for the low settings on a cooktop appliance?
All the cooktops I'm familiar with require a neutral, but this is not an NEC requirement, the seperation of the neutral (if present) and EGC in new installations is however.

Roger
 
Re: cooktop / oven

Some cooktops/ranges, etc do require a neutral because some of the controls {clock,limits controls,etc} require 120v to operate.Therfore the neutral must be inplace in the event a different appliance is installed.
 
Re: cooktop / oven

Originally posted by rob1kva:
. . . Therfore the neutral must be inplace in the event a different appliance is installed.
It is not the intent of the Code to require you to plan for something that may be done in the future. However, it is a great idea to do the planning and to provide for the future. This is a design issue, not a Code issue. :D
 
Re: cooktop / oven

I ran into exactly this problem a couple years ago.Inspector insisted we needed a neutral to a cook top that had pigtail with 2 hots and ground and no neutral.To shut him up we added a neutral wire nuted off inside cook top.We had 4 wires at junction box but he insisted it have neutral wire that went to nothing.To keep from holding up a closing we gave in
 
Re: cooktop / oven

Jim same as replacing a 3 wire cord with a 4 wire cord cap and wire both neutral and ground terminate at the same place in the
range but between it is code compliant that`s what is the key.Rob1kva You are so right 120 v clocks and lighting is where there is needed a Neutral.As lomg as we provide an isolated ground to a receptacle then well did our job today.The rules change every 3 years or so here at least.Now our AHJ wants to see the ufer on final after being sighned off on ufer rough inspection
we have a meeting tommorow with the county tomorrow.All Contractors, subs and all involved with this growth Burst are invited I have a list to give out there well lets see where it goes ????????????
 
Re: cooktop / oven

Originally posted by rob1kva:
Therfore the neutral must be inplace in the event a different appliance is installed.
Totally false statement. :roll:
With that "Logic" I shoud install a 60 amp circuit just in case they replace a cooktop with a 30 amp load with one that draws a higher load. Not happening.
 
Re: cooktop / oven

all of the ranges I have ever worked on require the neutral because the neutral goes to the common bus for the cook top and the common to the range elemenmts as well as the clock and dtimer. Check the net for electric range wiring diagrams and locate any generic diagram and you wiil soon see why the standar range plug has 4 leads. 2 hot a neutral and an egc lead.
 
Re: cooktop / oven

Perhaps Electricmanscott's 30 amp range is a bad example. It would seem the minimum range ampacity is 40A (210.19 3)...of course this assumes a min of 8.75Kw. Here in Denver, the ranges are all assumed to be 50A or greater, anyone find that in the code book, maybe that's just our trade practice.

Also reading the same article, looks like NEC specs the nuetral to be not less than 70 percent of the branch-circuit rating. I think that would rule out not having a nuetral. I understand the existing branch circuit installation provisions of 250.140 mentioned earlier.
 
Re: cooktop / oven

Chris my example is for a cooktop, many of which have different load requirements. Also some cooktops are straight 240 requiring no neutral. Therfore no need to install one.
 
Re: cooktop / oven

On a job right now with 150 electric ranges.
No clock or lights and no internal wiring connected to the neutral terminal. The contractor is not installing neutral conductors.

All thou they are free standing units they are wiring them direct with FMC whips.

Russ
 
Re: cooktop / oven

Russ, if the contractor is not installing neutral conductors on 150 electric ranges, how do you feel about 220.22? Are FMC whips granted an exemption I'm not aware of? Can you cite an article that allows this? I don't think a FMC whip is that great of idea for a heavy appliance that slides in and out of a small recessed area...seems like it would damage the conduit and conductors. I would be interested in finding out more about your application.
 
Re: cooktop / oven

Chris, if there is no neutral required, why would you think 220.22 would even be in the conversation? :confused:

Roger
 
Re: cooktop / oven

I believe 220.22 applies to feeders and service loads.. we are talking about branch circuits.....250.140, 250.134, 250.138 sums it up. I remember this code change ( in 1996 I think)and the intent was not to use the grounded conductor to ground current carrying parts.
 
Re: cooktop / oven

I guess I'm getting turned around. Feeder provisions of 220.22 talk about the importance of only derating the ampacity by 70 percent for a neutral, but your saying it's allowed to skip running a neutral altogether for the branch circuit.

Maybe I'm misreading 250.142 b ex 1 (the provision I was eventually referred to from 250.140)...doesn't it say you're only allowed to skip the neutral on existing installations? What's your interpretation.
 
Re: cooktop / oven

no. It is saying if you have an exsisting installation, you can use the grounded conductor to ground the frame of a range or dryer like we used to do,,, EG; a 3 wire range or dryer recept/circuit
 
Re: cooktop / oven

I'm talking about 250.142(B). otherwise you must have an EGC and can not use the grounded conductor for this use. If you have a straight 240V cook top, there is no reason for a neutral and 250.142 (B) does not apply. you only need a EGC
 
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