50 amp cooktop

[Grouch1980]

Hi all again!
I’m working on an apartment that has 2 panels... each one with its own meter. It was 2 apartments, and now being merged into one. So we’re keeping both panels. One of the panels is a fed from a 60 amp breaker (breaker is at the meter center). This panel will be feeding a 50 amp electric cooktop in the kitchen. I was told that this is a violation, because in order to serve a 50 amp cooktop, that panel must be fed by a 100 amp breaker. Is this true and required by the NEC?

thanks!

 

[tom baker]

Who told you and what code section did they mention?

 

[Grouch1980]

Who told you and what code section did they mention?

The contractor told me. He did not mention a code section though.

 

[Grouch1980]

I’m familiar with the service switch for a single family residence to be at a minimum of 100 amps. But this is an apartment in a multi family building. Coming off a meter center full of apartment breakers. I’m not familiar with this requirement that he’s stating

 

[infinity]

Neither is he because it is not an NEC requirement.

 

[Dennis Alwon]

Is the panel only feeding the cooktop?

 

[hillbilly1]

That’s a cooktop? Sure it isn’t an oven cooktop combo? Most cooktops are 30 amp, with only a real high end one being 40.

 

[Grouch1980]

It might be an induction cooktop, I can't check that since i'm not at my desk.

In response to Dennis, the 60 amp panel is feeding the cooktop, some lights, and some gas loads. all the other heavy loads such as AC units, heaters, etc., are on the other panel.

 

[gadfly56]

That’s a cooktop? Sure it isn’t an oven cooktop combo? Most cooktops are 30 amp, with only a real high end one being 40.

My last home had an electric range/cooktop. I think I calculated you could get close to 50 amps with all 4 burners cranked while running the self-cleaning cycle, which gets to somewhere north of 500F for 3 hours.

 

[infinity]

Ask the electrician what code section would prohibit a 50 amp branch circuit fed from a panel with a 60 amp feeder of a load calc stated that the 60 amp feeder was adequate?

 

[Grouch1980]

Ask the electrician what code section would prohibit a 50 amp branch circuit fed from a panel with a 60 amp feeder of a load calc stated that the 60 amp feeder was adequate?

I just did actually. If I get a code section, I'll come back with an update.

 

[Fred B]

Just as a side note that may or may not apply to the 60A panel. Some of the smaller load panels that if they are back fed will reduce the panel capacity by a percentage or fixed amount depending on MFG. Had one that was a small SD100A subpanel that if was using a backfeed breaker rather than the main lugs was reduced to a max of 75A per MFG specifications. If similar conditions exist on that 60A panel the Mfg maximum allowed amperage may fall below needed amperage for the equipment.

 

[Grouch1980]

Just as a side note that may or may not apply to the 60A panel. Some of the smaller load panels that if they are back fed will reduce the panel capacity by a percentage or fixed amount depending on MFG. Had one that was a small SD100A subpanel that if was using a backfeed breaker rather than the main lugs was reduced to a max of 75A per MFG specifications. If similar conditions exist on that 60A panel the Mfg maximum allowed amperage may fall below needed amperage for the equipment.

ah. by back-feed, do you mean a breaker mounted on the actual bus of the panel, rather than a separate main breaker feeding into the bus? kind of like a back-feed breaker to connect a solar PV inverter? In my case, they were bringing up an actual code violation, instead of how the panel was constructed.

 

[Grouch1980]

Just an update, the electrician was not able to send me the code section where a 50 amp cooktop required at least a 100 amp main breaker for the apartment. He was probably confusing it with section 230.79(C), which is for a one family dwelling... I asked him if that's what he may have been thinking of, but no response on that either. Personally I think that's what he was thinking of.

 

[infinity]

Just an update, the electrician was not able to send me the code section where a 50 amp cooktop required at least a 100 amp main breaker for the apartment. He was probably confusing it with section 230.79(C), which is for a one family dwelling... I asked him if that's what he may have been thinking of, but no response on that either. Personally I think that's what he was thinking of.

Well as is often the case people hear things that are "in the NEC" and believe it until they're actually called out to prove it. Glad you asked until you got an answer. I work with guys like this every day and it's amazing to hear code "requirements" from guys who's newest code book was from apprentice school in the 90's.

 

[Hv&Lv]

Well as is often the case people hear things that are "in the NEC" and believe it until they're actually called out to prove it. Glad you asked until you got an answer. I work with guys like this every day and it's amazing to hear code "requirements" from guys who's newest code book was from apprentice school in the 90's.

I’ve had people tell me for years it was illegal to put UF in conduit.
I‘ve asked them to show me where it says that in the book…

 

[infinity]

I’ve had people tell me for years it was illegal to put UF in conduit.
I‘ve asked them to show me where it says that in the book…

Yes, years ago we had a thread about code myths and the list was long. Many of them I had heard through out my career.