When a self-excited generator is loaded so that the output voltage is zero, why is there still output current? Even though there is no field current. The only thing I can think of is its residual EMF or its coming from the armature. Also, has anyone heard of a E_o "EMF with a subscript o"? would it be the same as E_a?

 

If this is a self exited DC generator then there is always Residual field of some level, this is how it starts in the first place as a rule.
Max.

 

Thanks!