PPT Slide
Section 13.9: Starting of DC Motors
On starting, E = k1nf = 0 V. (since n = 0 RPM)
By KVL: Ia = (Vt - E)/Ra = 230 V./.05 W = 4.6 KA. and
Pa = (Ia)2Ra = 1.058 MW = 1.42 Khp >> 50 hp = rated hp
Where is this power going?
In practice, high starting currents are limited by way of a starting mechanism which places resistance in series with the armature during startup