Restaurant load call question

[lheblen]

I am trying to determine that ampacitu needed for a restaurant. My question is when calculating ampacity for electric ranges (Mongolian table mounted grills),
Do I derate ampacity for the number of cooktops (30) @ 65% before applying 255.88? Each range has (5) 650 kw burners for 3250 kw each and are 120 v. So 30 is 97500
Times .65=63375

So is 63375 kv the number I would use to apply to 255.88? For the cooktops only, obviously.

Other loads I think I have a grasp on other loads just wanted to see if I am applying rules correctly for the cooktops

 

[wwhitney]

Do I derate ampacity for the number of cooktops (30) @ 65% before applying 255.88?

Presumably you mean 220.88. And the answer is no, you take 100% of all 30 cooktops.

220.88 says it is "in lieu of Part III of this article." Table 220.56 "Demand Factors for Kitchen Equipment--Other than Dwelling Units" is within Part III of the article, so it definitely doesn't apply when using 220.88.

In fact ignore all of 220.40 through 220.61 when using 220.88. So for example 220.60 on "Noncoincident Loads" does not apply. If you have noncoincident loads, you still need to include all of them before applying the Table 220.88 demand factor.

I have no experience with 220.88, so I don't know if it is likely to give you a better (smaller) answer than Part III would, it presumably depends on the details of the loads.

Cheers, Wayne

 

[zbang]

Each range has (5) 650 kw burners

Not 6.5 kw each? Even five times that is a whole lot of heat in a small area. The biggest teppanyaki grills I've found online are under 8kw per burner.

Got a photo of the nameplate or a model #?

 

[lheblen]

Not 6.5 kw each? Even five times that is a whole lot of heat in a small area. The biggest teppanyaki grills I've found online are under 8kw per burner.

Got a photo of the nameplate or a model #?

I apologize. They are 650 watts each and 5 per unit. 27 amps each at -20 volts.

 

[herding_cats]

Contact a qualified electrical contractor to review this in person. Have him examine the name plates.