When two D.C. series generators are running in parallel, an equilizer bar is used so that two similar machines will pass approximately equal currents to the load.
For the parallel operation of two or more D.C. compound generators, we should ensure that series fields of all generators should be either on positive side or negative side of the armature.
Compensating windings are used in D.C. generators to neutralise the cross-magnetising effect of the armature reaction.
In D.C. generators the pole shoes are fastened to the pole core by counter sunk screws.
D.C. generators are connected to the busbars or disconnected from them only under the floating condition to avoid sudden loading of the primemover, to avoid mechanicaljerk to the shaft, to avoid burning of switch contacts.
D.C. generators are installed near the load centres to reduce line losses.
D.C. generators are normally designed for maximum efficiency around full-load.
When two D.C. series motors are connected in parallel, the resultant speed is normal speed.
In D.C. generators the polarity of the interpoles is the same as that of the main pole ahead.
In D.C. generators, the brushes on commutator remain in contact with conductors which lie under interpolar region.
In D.C. generators, current to the external circuit from armature is given through commutator commutator.