ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
(OP)
I have an Architect disagrees with me that adding up all three phase currents at the bottom of a panel schedule will total up to the size of what ever panel size.
Can some one clarify this to me?
Also recent reading taken by an Amp -probe in all three phase feeders in a 400 Amp panel adds up to 470 Amps. I am not sure how this is possible?
Thanking you in advance.
EEAOC
Can some one clarify this to me?
Also recent reading taken by an Amp -probe in all three phase feeders in a 400 Amp panel adds up to 470 Amps. I am not sure how this is possible?
Thanking you in advance.
EEAOC






RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
It is a different matter that Code requires not to load a panel more than 80% of its rating unless it is listed for 100% use. (using 100% rated breakers).
RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
If the load exists for more than 3 hrs the rating must be reduced to 80% of the breakers name plate listing.
RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
THERETICALY FOR A BALLANCED LOAD AS EACH PHASE IS 120 DEG APART THEY AD UP TO ZERO.
RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?
That zero sum is is only for the summation of currents in the neutral (for fundamental frequrency currents). That does NOT amount to zero power.
400A in three phases is equivalent to 1200A single phase current in terms of power consumption.
Total power for a 400A, 3-phase system is 1.732*V*400*pf where V is line to line. Which equals (3)*(V/1.732)*400*pf or 3 times the 1200A*single phase voltage.
RE: ADDING UP ALL 3 PHASE CURRENT IN A PANEL SCHEDULE?