Table 220.55

[Tainted]

For me table 220.55 has always been the hardest to grasp in article 220

There is an oven rated 2200kw
and a cook top rated 11500kw

What is the demand load? I am getting 11kw is this correct?

 

[Tainted]

for cooking appliances i meant to say watts, not kilowatts

 

[Dennis Alwon]

If I recall you can add the watts of one oven and one cooktop and use column C and treat it as one range.

That would mean 1 unit at 14kw but I believe you can also do them separately using col A and C

 

[augie47]

Average the two using 12 as the smallest number...gives you an average of 17.... 5% for each kw over 12... If I did the math correct = 14

 

[Tainted]

I am so confused how did we go from 13700 total watts to 14kw?

 

[Tainted]

Shouldn't the demand load then be 8.8kw? using note 1

 

[Dennis Alwon]

Shouldn't the demand load then be 8.8kw? using note 1

Yes

 

[Dennis Alwon]

Average the two using 12 as the smallest number...gives you an average of 17.... 5% for each kw over 12... If I did the math correct = 14

12 + 2.2 = 14.2= 14

8 + .8 = 8.8

 

[augie47]

Look at Example D6B in Annex D (Pg 799 in '17)

 

[Dennis Alwon]

Look at Example D6B in Annex D (Pg 799 in '17)

I still don't get it. Note #4... This is for branch circuit but I assume it would be the same for the demand load

The example you showed was for ranges only. You are dealing with averages here we are not just using Note #4

 

[Dennis Alwon]

If someone thinks note #4 doesn't apply for demand load then you would have to use each one individually. The 11.5 kw = 12 kw = 8kw demand from table

2.2 kw *80% = 1.76 =

8kw + 1.76 Kw = 9.76= 10 kw

 

[Tainted]

If someone thinks note #4 doesn't apply for demand load then you would have to use each one individually. The 11.5 kw = 12 kw = 8kw demand from table

2.2 kw *80% = 1.76 =

8kw + 1.76 Kw = 9.76= 10 kw

I'm confused now, is the answer 8800W or 10000W lol

 

[Dennis Alwon]

I'm confused now, is the answer 8800W or 10000W lol

IMO... it 8.8

If this is for a test I believe 8.8 is the answer. The 10kw is another way to calculate it. Using Note 4 I see the answer as 8.8

If you have 2 units- cooktop and oven they can be added together. Let's face it a range is nothing but a cooktop and an oven. I would just ignore the 10kw it complicates things and wasn't necessary.