Load Calculation in Excel

[Npstewart]

Hi Everyone.

We have a excel spread sheet that I made for our company for panel schedules. I plan on making a MDP panel schedule so I dont have to do a manual one in autocad.

On the individual panels we have a receptacle column, so if we have greater then 10 kW of receptacles the rest is taken at 50%. So on my MDP should I just sum the total of the panels I am feeding or do I have to figure out my TOTAL receptacle load for all the panels, subtract 10 kW and then take 50% of the TOTAL receptacle load??

 

[Volta]

IMO, you do not have to, but are allowed to figure it again at the MDP if you want to take full advantage of the diversity at that level.

I would caution anyone doing so however to be sure that only allowable receptacles are included. I often see plans, approved, that include in that column cord / plug connections for specific equipment. AFAIK that is not allowed, but commonly done.

 

[Smart $]

Hi Everyone.

We have a excel spread sheet that I made for our company for panel schedules. I plan on making a MDP panel schedule so I dont have to do a manual one in autocad.

On the individual panels we have a receptacle column, so if we have greater then 10 kW of receptacles the rest is taken at 50%. So on my MDP should I just sum the total of the panels I am feeding or do I have to figure out my TOTAL receptacle load for all the panels, subtract 10 kW and then take 50% of the TOTAL receptacle load??

Let me put it like this:

Panel 1 - 30kVA: 10kVA + 10kVA = 20kVA
Panel 2 - 30kVA: 10kVA + 10kVA = 20kVA
MDP......................................... = 40kVA

or

MDP - 60kVA: 10kVA + 25kVA = 35kVA

 

[Shoe]

IMO, you do not have to, but are allowed to figure it again at the MDP if you want to take full advantage of the diversity at that level.

I would caution anyone doing so however to be sure that only allowable receptacles are included. I often see plans, approved, that include in that column cord / plug connections for specific equipment. AFAIK that is not allowed, but commonly done.

Right or wrong, I'm guilty of this but only because the code is insanely conservative on this calculation and only if the connected equipment is intermittent.