I went to a new residential development today and was loooking at the panel size in one of the units. It's 1200 sq ft with disposal, dishwasher, range hood,door opener, gas furnace,h20 tank(4.5 kw)) electric range, and central air(4kw).I made a note of what was in the place because I couldn't believe all these units(over 100) were wired with 100A feeders from the meter bank. I came up with 117A for 120/240V 1 phase .It gets even better, there are also a dozen or so 2000sq ft units with the same equipment on the property and they are wired with the same size feeder. Some of the feeder runs are over 150' in length, everything is #2 AL regardless of distance or load. These units are new within the past year, am I missing something? I can't see how they passed inspection. Am I wrong with my calc, seems 125A would have been the min for the 1200sq ft units. Curious as to others thoughts.
General Lighting and receptacles(2000sf @ 3VA) 6.0
Cooktop 8.5
Small Appliances 1.5
Small Appliances 1.5
Refrigerator 1.2
Dishwasher 1.2
Disposal 1.0
Hood 1.2
WH 4.5
Total Connected load without AC
26.6
1st 10KVA @ 100% 10.0
Remainder @ 40% 6.6
Total demand without AC
16.6
AC1 (Highest load) 4.0
Total Demand 20.6
Volts 240.0
Amps
86.0
Don't see anything wrong with the 100A
And let's be honest, how many refrigerators use 1.2KVA nowadays? I got one of the biggest in my home(short of going subzero) and it's rated 600W something.. Same goes for dishwasher and disposal. Not to mention, the refrigerator could actually be one of the small appliances circuits, so you can knock another 1.2KVA COMPLETELY from my calculations.
150' is not really that far when it comes to voltage drop, NEC recommends (NOT REQUIRES) combined 5%. In a 2K Sq/FT apt branches will have VERY LITTLE voltage drop.
Not to mention most loads in a resi are resistive, meaning if there's a voltage drop the heat will be less and that's all. And the inductive loads in a resi are more than likely able to run on 200V.
As a matter of fact 86A will cause a VD of about 8.23, which is about 3.5%, which is almost there. And again, I seriously doubt the branch in such a small place would incurr more than another 1.5%
