Question

A 4-pole generator delivers 143 A of current. It is lap connected and has 492 conductors. The shunt field takes around 10 A current. If the brushes are given a mechanical lead of 10 degrees, then what is the demagnetizing ampere turns per poles?

• A. 980 AT
• B. 261.375 AT
• C. 1500 AT
• D. 1260 AT

Answer 1

The correct option is B 261.375 AT

$(AT{)}_{demag}=\left(\frac{I_a}{A}\right)\times \left(\frac{Z}{2P}\right)\times \frac{2\theta }{{180}^{\circ }}$

$I_a=143+10=153A$

$\therefore (AT{)}_{demag}=\frac{153}{4}\times \frac{492}{8}\times \frac{2\times 10}{{180}^o}$

$=261.375AT$