It seems that most people are missing the point.
First of all, to the people who question how I have that kind of electrical
When the basement is complete I will have a three story home with approx 3000 sq
ft, and at least six bedrooms. A home theater, and a photography studio, plus
woodworking equipment in the garage - table saw, drill press, planer, band saw
etc. For heating/cooling I have three a/c compressors, including a heat pump
with a 5kw heating element. Double ovens in the kitchen. One large fridge,
large freezer, plus two small fridges. Attic ventilator, dishwasher, electric
clothes dryer. These things add up. And the shop equipment wasn't even
factored in, because I only use those one at a time on a 20A circuit (no 220v
equipment). Nor am I factoring in the home office with several PCs on all the
time, with a floor standing 8000BTU A/C unit to keep the room cool.
My current system would handle everything fine, but the addition of the basement
changes everything. I really don't understand why they didn't put a 200A in to
Secondly, to the people who say that I will never have that kind of demand at
I freaking know that. That's not the point. The point is, will it pass
inspection? What am I going to do if the inspector looks at the size of my home
and all the breakers crammed into the box, asks for a load calc, and I say "well
it's over 150A but hey I doubt I'll use it all the time"? The worksheet that I
used came from a book based on the 2005 NEC, and the formulas take into
consideration the fact that you aren't pulling the entire load all the time.
The final figure is a minimum, which means my box has to handle it.
As it turns out, I did make one error by not reducing the load from my double
ovens to 65%, which changed my total load to 171A. Still higher than 150A but I
get a bit more room.
Lastly, I want capacity for future renovations, like a screened in deck. And
the extra panel size will avoid a subpanel, which is a good thing because the
room with the breaker boxes will be my future office.