field ground relay
field ground relay
(OP)
http://img269.imageshack.us/img269/2697/adszxs.jpg
hello, I wonder how a scheme is this.İf the injection is made through, so wont the rectifier d.c voltage be short circuited or complete its path from the ground brushes?
hello, I wonder how a scheme is this.İf the injection is made through, so wont the rectifier d.c voltage be short circuited or complete its path from the ground brushes?






RE: field ground relay
RE: field ground relay
RE: field ground relay
So if you had a 250V field, instead of it floating between about -125 and +125 it now is +50 (say) to +300. A bit more stress on the insulation but not much.
The field DC source and the ground fault detection DC source are independent of each other and form different current loops; the field ground source being open circuited except during a field ground.
The brush in question is a shaft ground brush, has nothing to do with the field brushes.
RE: field ground relay
The Vdc source at the lower left of the drawings has a single connection to the exciter/field winding. No sensing current can flow through the 64G relay until a ground fault occurs in the winding and completes the circuit: From +Vdc through the 64G relay to the negative field lead to the ground fault then back through the rotor frame, rotor shaft, grounding brush, ground and to the -Vdc connection.
Current only flows in the sensing circuit when a ground fault occurs (ignoring initial energization when some current flows through the winding-to-ground leakage capacitance).
RE: field ground relay