I am looking at a 3-phase 4-wire panel. 102/208 volts, fed with 400 mcm. Panel is rated at 400 amps. After looking in code book, it seems to me that i should only figure that the panel is capable of only 300 amps.
This panel has (4) 3pole 100's and (1) 2pole 100's existing. These breakers feed units in the building that are now pretty much just living spaces. Lights and plugs, not much else. Maybe a small water heater, and electric stove in each unit.
My customer would like me to install (2), possibly (4) new single phase 100 amp distribution panels. There is room in the panel, but i am not sure if the main feed can handle this addition.
Im pretty sure that all existing circuits in this panel have hardly any kind of draw at all as we speak. Should i measure each phase conductor and see how much current draw is actually being used? Or is there some formula i can use to figure out if it would be safe to add more distribution panels off of this main.
I don't want to walk every unit that is powered by this panel and do load calc. Maybe set up some kind of current transformer that will measure the peak amount of current used at one time? Is there such an instrument, tester?
This panel has (4) 3pole 100's and (1) 2pole 100's existing. These breakers feed units in the building that are now pretty much just living spaces. Lights and plugs, not much else. Maybe a small water heater, and electric stove in each unit.
My customer would like me to install (2), possibly (4) new single phase 100 amp distribution panels. There is room in the panel, but i am not sure if the main feed can handle this addition.
Im pretty sure that all existing circuits in this panel have hardly any kind of draw at all as we speak. Should i measure each phase conductor and see how much current draw is actually being used? Or is there some formula i can use to figure out if it would be safe to add more distribution panels off of this main.
I don't want to walk every unit that is powered by this panel and do load calc. Maybe set up some kind of current transformer that will measure the peak amount of current used at one time? Is there such an instrument, tester?
