range or oven... what's the difference?

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Mr. Spinosa

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I am using a calculations book to study for my administrator's exam. - I haven't been directly told this but in the language of the NEC it seems that a range and an oven are two different things. For example. In note 4 of table 250.55 it states that the branch circuit load for one range can be calculated in accordance with table 250.55. - In the next sentence it states for one wall mounted oven or counter mounted cook top we are to use the nameplate rating.
If I have a question that asks what is the branch circuit load rating for a 5kw oven used in a household? - Would I treat this as a wall mounted oven and use the nameplate rating. I am assuming yes. - It appears it has to say range in order to use the table rating for this kind of question. Am I correct? (I know this may sound silly but oh well...:slaphead:)
 
Mr. Spinosa said:
I am using a calculations book to study for my administrator's exam. - I haven't been directly told this but in the language of the NEC it seems that a range and an oven are two different things. For example. In note 4 of table 250.55 it states that the branch circuit load for one range can be calculated in accordance with table 250.55. - In the next sentence it states for one wall mounted oven or counter mounted cook top we are to use the nameplate rating.
If I have a question that asks what is the branch circuit load rating for a 5kw oven used in a household? - Would I treat this as a wall mounted oven and use the nameplate rating. I am assuming yes. - It appears it has to say range in order to use the table rating for this kind of question. Am I correct? (I know this may sound silly but oh well...:slaphead:)
Click to expand...

Note it says (even in what you quoted) one wall mounted oven or counter mounted cook top.

You can have a cook top and an oven on same circuit and treat them like a range but as individual units - the demand factor does not work out so well because with a range or combination of units they cycle elements on and off as needed and the resulting total load is likely less because not all are on at same time. With a single unit more will be on at a time because there is less to be on at one time.

You probably meant 220.55 and not 250.55 (250 is grounding).
 
I'm not going to try to answer exactly, I will say in most times that it's word play, and one better pay attention to the words being stated!

I also want to state "Charlie's Rule" post #6. :)

Welcome to the Forum!
 
Much loved, well misunderstood; wait were talking about The NEC...

As soon as I read:
... I haven't been directly told this but in the language of the NEC it seems that a range and an oven are two different things.
Click to expand...

Charlie's Rule is in... JMO...

:D
 
But wait,
range and oven are two different things. Aren't they?

range is the unit that slides in and has oven built in and the oven is the unit that has a door without a cooktop and is usually a built in unit.

am i not correct??
 
edward said:
But wait,
range and oven are two different things. Aren't they?

range is the unit that slides in and has oven built in and the oven is the unit that has a door without a cooktop and is usually a built in unit.

am i not correct??
Click to expand...

Yep, except that I owned a range that had 2 ovens and a cooktop. Similar to the picture below.

02260673000
 
edward said:
But wait,
range and oven are two different things. Aren't they?

range is the unit that slides in and has oven built in and the oven is the unit that has a door without a cooktop and is usually a built in unit.

am i not correct??
Click to expand...

You are correct. The range is a combination unit and therefore more load diversity which is why demand factors are allowed to be applied to it.

Demand factors are also allowed to be applied to cooktops and ovens when installed together, but if on individual branch circuits there is not the same load diversity on an individual circuit and that is probably why the nameplate values are necessary for determining load at 100%.

If you have a cooktop and an oven on separate circuits you apply 100% for purpose of sizing the individual circuits, but can still apply demand factor if they are both on a feeder or service.

Please note that 220.55 is in 220 Part III - Feeder and Service Load Calculations so it applies to feeders and services.

At the bottom of the table Note 4 (the question in the OP is primarily about this note) it is stating a condition of how this table can apply to branch circuits.
 
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