Nishant Choudhary

 Profile Answers by Nishant Choudhary Questions by Nishant Choudhary

• Jun 3rd, 2011

 

it does not effect the speed it is done to reduce sparking at the commutator contacts

bittu123

 Profile Answers by bittu123 Questions by bittu123

• Nov 9th, 2011

 

Since reversal of current take places at MNA not at GNA, So, commutation can be improved by putting brush at MNA. Otherwise it leads sparking and damaging brushes and commutator.

If load connected across generator is constant, increase in speed will increase voltage, so, current will be increased.
It results in more armature reaction and larger angle for MNA(means MNA will shift more). So, One have to shift the brush position according to shift in MNA, otherwise poor commutation will result.

So, speed change may affect commutation if brush position would have not changed accordingly