In single phase energy meter,
Current coil is made up from thick wire having few no. of turns.
Pressure coil is made up from thin wire having more no. of turns.
P = 10 kW
VL = 400 V
IL = 20 A
3- phse power, P = √3*VL*IL*cosφ
cosφ = 10*1000/(√3*400*20)
Conductor with higher temperature ratings, provide the ampacity is determined based on the 60°C ampacity of the conductor.
Slip, s = (Ns - Nr)/Ns
Ns = 120f/P
0.05 = (1000 - Nr)/1000
Nr = 950 rpm
Speed of rotor with respect to stator magnetic field = 950 - 1000 = -50 rpm
Speed of the stator magnetic field with respect to stator core = 0
Speed of the rotor magnetic field with respect to rotor = sNs
Speed of the stator magnetic field with respect to rotor magnetic field = 0
Speed of the rotor magnetic field with respect to stator core = Ns