I need to find out if I an existing 600 amp 3 phase 120/208 service switch is adequate for the existing apartment load.
I have a multi-dwelling - 7 apts, (5)- 1542 sqft, (2) - 1144 sqft
each residential apt has 120/208 3 phase 4 wire 175 amp panel
In addition to the light/app/laundry load, each apt has
(1)- 1800 va dishwasher
(1)- 21.84 Kva 208v single phase tankless water heaters
(3) - 4.5 Kva electric room heaters
6.5 Kva cooktop
4.2 Kva oven
no dryer load
I can't find the section for calculating the tankless or 3 phase equivilent load . I was told by the manufacturer that the tankless water heaters are non-continuous. I need to use the optional method for this, but do I need to find the 3 phase equivilant total load, derate them first then add that total to the building load, or what... for the total load?
Same question about 3 phase equivilent load for the range and heaters
I came up with 397696 va @44% / 360v = 486 amps per phase.
Anybody...can you double check this or comment?
I tried to follow along with Annex D5(a) but I can't seem to come up with their numbers to understand how they got them.
oh...being NYC it has to be NEC 2005
I have a multi-dwelling - 7 apts, (5)- 1542 sqft, (2) - 1144 sqft
each residential apt has 120/208 3 phase 4 wire 175 amp panel
In addition to the light/app/laundry load, each apt has
(1)- 1800 va dishwasher
(1)- 21.84 Kva 208v single phase tankless water heaters
(3) - 4.5 Kva electric room heaters
6.5 Kva cooktop
4.2 Kva oven
no dryer load
I can't find the section for calculating the tankless or 3 phase equivilent load . I was told by the manufacturer that the tankless water heaters are non-continuous. I need to use the optional method for this, but do I need to find the 3 phase equivilant total load, derate them first then add that total to the building load, or what... for the total load?
Same question about 3 phase equivilent load for the range and heaters
I came up with 397696 va @44% / 360v = 486 amps per phase.
Anybody...can you double check this or comment?
I tried to follow along with Annex D5(a) but I can't seem to come up with their numbers to understand how they got them.
oh...being NYC it has to be NEC 2005