Oven Wire Size Question

[letgomywago]

I suppose its all in how you interpret 'one wall-mounted oven. To me its a double oven but it is a single wall mounted appliance so yeah I'd say to be safe your right 50A circuit.

I shoot for 6666 ser for things like this it's just easier. If worried about the copper only conductors then hit a 4 11/16 in cabinet and use splice reducers to 6in copper then the leads but I've never worried if using splice reducers or dual rated split bolts

 

[Dennis Alwon]

I shoot for 6666 ser for things like this it's just easier. If worried about the copper only conductors then hit a 4 11/16 in cabinet and use splice reducers to 6in copper then the leads but I've never worried if using splice reducers or dual rated split bolts

Why would you pull a #6 equipment grounding conductor? Do they even make 6-6-6-6 ser? I guess for a 3 phase service of 60 amps????

 

[letgomywago]

Why would you pull a #6 equipment grounding conductor? Do they even make 6-6-6-6 ser? I guess for a 3 phase service of 60 amps????

Thats standard 50a SER. They make a copper 6668 but all the aluminum is 6666

 

[Jpflex]

Simple, it's wrong. It does say that you need to follow the code so you can ignore their mistake. This is similar to a recent thread about how poor instructions can be.

This was the point that I brought up before. The NEC requires manufacture instructions to be followed and takes priority over NEC general instructions. Whose fault would the electrical inspector likely pin for this, if this setup resulted in an insulation fire? Especially the installer running 10 AWG wire on a 50i breaker according to manufacture listed instructions?

 

[infinity]

This was the point that I brought up before. The NEC requires manufacture instructions to be followed and takes priority over NEC general instructions. Whose fault would the electrical inspector likely pin for this, if this setup resulted in an insulation fire? Especially the installer running 10 AWG wire on a 50i breaker according to manufacture listed instructions?

IMO no good inspector is going to let the installer follow those instructions when then directly contradict the NEC requirements.

 

[tortuga]

The NEC requires manufacture instructions to be followed and takes priority over NEC general instructions.

Do you have a code reference for that "takes priority part"?

 

[Birken Vogt]

This was the point that I brought up before. The NEC requires manufacture instructions to be followed and takes priority over NEC general instructions. Whose fault would the electrical inspector likely pin for this, if this setup resulted in an insulation fire? Especially the installer running 10 AWG wire on a 50i breaker according to manufacture listed instructions?

If you followed the mistaken instructions, and put that setup on 10 AWG, the wire would never even get warm.

Still wrong, but it would work.

 

[NoahsArc]

since locally we only do gas.

Speak of the damned devil. Good thing I just did my homework. Love how that works out sometimes. (this guy has a gas line in the pic he sent me, I don't get it at all)
I've got an 11.4kw range -> 220.55 -> 8kW -> 34A -> 40A minimum. 2x #8 and a #10 THHN neutral sounds gtg

According to note 4 that demand factor only applies to a range.

"for one wall-mounted oven or one counter-mounted cooking unit shall be the nameplate rating.... load for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch circuit.... add the ratings as equivalent to one range."
I don't see a clear distinction there.

@SteveO28 what pricing did you settle on?

 

[texie]

Installing a double oven for a new kitchen. LG WDEP9427. Install manual says it requires a 50amp breaker with 10g wire. Oven draws 42.5 amps. I planned on running a 6awg based on 42.5x1.25= 53.125a. Anyone want to fill me in why the manual calls for 10s?

Electrical Requirements; Making Electrical Connections - LG PrintProof WDES9428 Series Installation Manual [Page 12]

LG PrintProof WDES9428 Series Manual Online: electrical requirements, Making Electrical Connections. Ensure That Dedicated Circuit Protection Is Prepared As Recommended And That The Appliance Is Grounded Properly. • This Wall Oven Must Be Electrically Grounded In Accordance With Local...

www.manualslib.com

This is a case where the NRTL should be notified so they can have corrections made in the docs. As mentioned here and in the previous post about this, in my view this is a chronic problem with all the NRTLs.

 

[infinity]

I don't see a clear distinction there.

Here is the entire note, there is a distinction between a range and a wall mounted oven. The range can use the demand factor in Note #4 of T220.55, second sentence. The wall mounted oven uses the KW rating (third sentence) to determine the branch circuit size without the demand factor.

Note 4.
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.

 

[NoahsArc]

For whatever reason now I see it, despite reading the same thing both times. I think italics was the issue.. not me.

 

[wwhitney]

Here is the entire note, there is a distinction between a range and a wall mounted oven. The range can use the demand factor in Note #4 of T220.55, second sentence. The wall mounted oven uses the KW rating (third sentence) to determine the branch circuit size without the demand factor.

As a devil's advocate, I will observe that there are 1,800W counter-mounted cooking units available, such as:

Avanti IH1800L1BIS 12 Inch Induction Cooktop with 1,800 Watt Cooking Power, 6 Preset Temperature Settings, Automatic Shut-off Safety Sensor and Touch Sensor Control Console

Avanti IH1800L1BIS 12 Inch Induction Cooktop with 1,800 Watt Cooking Power, 6 Preset Temperature Settings, Automatic Shut-off Safety Sensor and Touch Sensor Control Console

www.ajmadison.com

Therefore it should be permissible to use an 1,800W allowance for a counter-mounted cooking unit in applying T220.55. The double oven is 10,700W, plus the 1,800W allowance makes 12.5 kW. So the Column C rating is 8 kW * 1.05 = 8.4 kW = 35A @ 240V. [Same calculation would apply for up to a 2,700W allowance for the cooktop, if 0.4 kW is not a "major fraction" of a kW.]

This line of thought would permit a 35A branch circuit with 35A OCPD.

Cheers, Wayne

 

[infinity]

As a devil's advocate, I will observe that there are 1,800W counter-mounted cooking units available, such as:

Avanti IH1800L1BIS 12 Inch Induction Cooktop with 1,800 Watt Cooking Power, 6 Preset Temperature Settings, Automatic Shut-off Safety Sensor and Touch Sensor Control Console

Avanti IH1800L1BIS 12 Inch Induction Cooktop with 1,800 Watt Cooking Power, 6 Preset Temperature Settings, Automatic Shut-off Safety Sensor and Touch Sensor Control Console

www.ajmadison.com

Therefore it should be permissible to use an 1,800W allowance for a counter-mounted cooking unit in applying T220.55. The double oven is 10,700W, plus the 1,800W allowance makes 12.5 kW. So the Column C rating is 8 kW * 1.05 = 8.4 kW = 35A @ 240V. [Same calculation would apply for up to a 2,700W allowance for the cooktop, if 0.4 kW is not a "major fraction" of a kW.]

This line of thought would permit a 35A branch circuit with 35A OCPD.

Cheers, Wayne

I'm confused, is there a counter mounted unit in the OP's question or are you just outlining other possible scenarios?

 

[Birken Vogt]

I'm confused, is there a counter mounted unit in the OP's question or are you just outlining other possible scenarios?

I think he is using it like the apartment electric kitchen calculation which leads to a lower number even if the apt is using gas cooking.

Same deal here, add a phantom cooktop and you get a lower number than just the oven by itself.

 

[Hv&Lv]

This was the point that I brought up before. The NEC requires manufacture instructions to be followed and takes priority over NEC general instructions. Whose fault would the electrical inspector likely pin for this, if this setup resulted in an insulation fire? Especially the installer running 10 AWG wire on a 50i breaker according to manufacture listed instructions?

IMO no good inspector is going to let the installer follow those instructions when then directly contradict the NEC requirements.

This is a case where the NRTL should be notified so they can have corrections made in the docs. As mentioned here and in the previous post about this, in my view this is a chronic problem with all the NRTLs.

As I read this I got to wondering..
So I did a thing. Just got this response:

 

[Jpflex]

As I read this I got to wondering..
So I did a thing. Just got this response:
View attachment 2571062

And there you have it. Manufacture listed instructions being incorrect but NEC requires manufacture instructions to take priority over NEC code.

 

[wwhitney]

NEC requires manufacture instructions to take priority over NEC code.

You have made this claim before, but on what basis? As far as I know, there is no language in the NEC to that effect.

Cheers, Wayne

 

[infinity]

You have made this claim before, but on what basis? As far as I know, there is no language in the NEC to that effect.

Cheers, Wayne

I agree. In fact most instructions, even those that are incorrect, will state that all applicable local codes must be followed.

 

[letgomywago]

So the way I personally reconcile code / instruction discrepancies is that they are code must be followed but instructions also must be so either a product is incompatible with a wiring method or location or it gets an above and beyond install.

Fridge says don't gfi well if in a location that requires gfi then the fridge is the wrong fridge.

Non damp rated light in a damp area then wrong light

Fitting says listed for 10 cables and nothing in code prohibits it then no issue till someone tries to use the wrong cable combinations or in a location other than what's in the instructions

 

[brycenesbitt]

Ovens use the 240V or 208V circuit to power the Watt-intensive heating elements, and the 120V circuit to power the fan and controls. This means the amount of current on the neutral is small compared to the amount on the live wires.

Looks like this one puts 0A on the neutral,
at least based on the European version of the same model.