Under running conditions, the frequency of the current in the stator circuit is *f* and that of the current in the rotor circuit is *f* _{2} = *f* _{s} is, so no common phasor diagram may be constructed for the two circuits. However such a phasor diagram may be plotted if we assume an equivalent blocked rotor in the motor for which a model circuit representing one stator and rotor phase is shown in Fig. 19. This figure also shows the phasor diagram thus constructed and the phasor diagram for a stator phase carried over from Fig. 14 . unchanged . The reference vector is Φ̇_{r} with respect to which the stator phase emf *Ė*_{l} and the phase emf of the equivalent blocked rotor. *Ė*_{2,br} , are in quadrature lagging .

With respect to -* Ė*_{2},_{br }the rotor current *İ*_{2} lags behind by an angle

φ_{2 }= arctan [(ɷ*L*_{leak},_{2}/(*r*_{w2}+* r*_{2})]

= arctan (sɷL_{leak},_{2}/*r*_{w2})

which is the same phase difference as is observed between -* Ė*_{2} and *İ*_{2} when the rotor is revolving (see Fig 16) .

The secondary circuit includes a resistance

*r*_{w2} + *r*_{2} = *r*_{w2}/*s*

and an inductive reactance ɷ*L*_{leak.2 }.Accordingly, *Ė*_{2},_{br} consists of an active component, *r*_{w2}* İ*_{2}/*s* , and a reactive component jɷ*L*_{leak,2}* İ*_{2 .}

The vector of the rotor phase current referred to the stator side is

*İ*'_{2} = (*m*_{2}*w*_{2}*k*_{w2}/3*w*_{l}*k*_{wl}) *İ*_{2}

and the stator phase current is

*İ*_{1 }= *İ*'_{2} + *İ*_{1,nl}

In the stator phase winding the referred current *İ*'_{2} corresponds to the rotor phase current *İ*_{2} which it compensates . The magnetizing current *İ*_{1,nl }, which accounts for a part of the stator phase current, excites the revolving magnetic field of the motor. The magnetizing current phasor leads the magnetic flux phasor by an angle 6 owing to hysteresis and eddy-current losses in the core. The phasor diagram of one phase of an induction motor with its rotor blocked is in effect the same as the phasor diagram of a transformer (see Fig. 11).

The stator phase voltage phasor is plotted on the basis of the following equation:

*V̇*_{1}* *= - *Ė*_{l} + *r*_{w1}*İ*_{1}+ *j*_{leak.1}*İ*_{1}