AC Motors
AC Motors
(OP)
I'm trying to figure-out what would be the approximate max. or by calculation of phase currents I1,I2,I3 in a 3 phase-four wire system, with a given 1875KVA/380Vac, rated generator.(Balance load)
The question is for me to determined the type of CT's to be installed in 3 phases for add/shedding application. Pls. assist--Thanks
The question is for me to determined the type of CT's to be installed in 3 phases for add/shedding application. Pls. assist--Thanks
C.A.A.





RE: AC Motors
RE: AC Motors
RE: AC Motors
{220V … 2.6A/kVA}
{480V … 1.2A/kVA}
{208V … 2.8A/kVA}
RE: AC Motors
I would rather choose to look for a whole package power monitoring device that will feed information to my program which monitors status of the loading condition of my genset.
I have variable 220Volts load with respect to ground.
I understand that total current from power formula is equal to all phase current say-- Ia,Ib,Ic at full load condition right?
C.A.A.
RE: AC Motors
RE: AC Motors
I mean to say total current as per specification from 1875KVA. Would it be It=Ia=Ib=Ic?
Thanks for being prompt.
C.A.A.
RE: AC Motors
It is likely that the only current of interest are the phase currents which are assumed equal, and can be used in the formula Stotal=sqrt(3)*VLL*Iphase.
(where S is va)
Note that if you represent the load as equivalent wye, the voltage across each phase is VLL/sqrt(3). We find the power across each of the single wye legs as:
S_singlephase=IV = Iphase*VLL/sqrt(3)
The total three-phase power is
S_three_phase = 3*S_singlephase
= 3*Iphase*VLL/sqrt(3)
= sqrt(3)*Iphase*VLL.
I'm not sure if that helps.
RE: AC Motors
S = Van*Ia + Vbn*Ib + Vcn*Ic
or, the description of apparent power is the sum of the products of each phase-to-neutral voltage and its associated phase current. Clear as mud, right?
RE: AC Motors
It helps me really.
csr
RE: AC Motors