220.87 EXCEPTION CALCULATION QUESTION

[vpower1989]

Hello All,

I used the exception to 220.87 a handful of times over the last few years and it looks like I am going to have to use it again. Of course I have the client install a meter on their panel feeder for 30 days to establish the actual maximum demand of the panel. The code then says I can take 125% * actual maximum demand and add my new load to it. One thing that is not clear to me is whether or not I can apply a demand factor to the new load prior to adding it to the actual maximum demand?

 

[Dennis Alwon]

It reads to me that you take 125% of the max demand load and then add your new load

 

[vpower1989]

It reads to me that you take 125% of the max demand load and then add your new load

Define "new load". Is it the full VA of the new load? Is it the VA adjusted by an allowable demand factor?

 

[Dennis Alwon]

The new load is your calculated load for the new equipment. Calculate the load as you would in art 220

 

[vpower1989]

The new load is your calculated load for the new equipment. Calculate the load as you would in art 220

Ok good that is what I was hoping to hear.