Question

A d.c. motor has the following spec: k×flux= 6.0v.s Vt= 10:0 V Ra= 1.5:00 Ia= 4:0 A (armature current at full load). Calc rated torque, starting torque; starting current at full voltage, starting speed; For Seperately excited and Shunt motor?

Answer 1

As per the given in the question,

k×flux= 6.0v.s

Vt= 10:0 V

Ra= 1.5:00

Ia= 4:0 A

We know that rated torque $(T)=k\times flux\times I_a$

$=6\times 4 =24Vs A$

suppose k =1

Starting torque $=KI_a^2$ $=4^2=16VsA$

starting current $(I)=\frac{Vt}{R}=\frac{10}{1.5}=6.66A$

starting torque for the shunt motor = KIa= 4VsA