User Manual M8100
M8196-72E
Page 3 of 7
1
Preface
This manual describes the M8100 Synchroscope with built-in check synchronizer relay and dead
bus closure function.
2
Function
The M8100 Synchroscope provides illuminated indication of the actual phase difference between
generator voltage and bus voltage. If the vector and the light spot turn clockwise, the generator
frequency is too high and must be reduced. The light spot turning anti clockwise indicates a lower
generator frequency, and consequently it must be increased.
In case the generator and busbar voltage and frequency and phase angle are within acceptable
limits, the built-in check synchronizer relay will activate. The limits of above parameters can be
adjusted by a potentiometer on the rear side of the unit.
For clearing of blackout situations the M8100 Synchroscope can be set up to connect a live
generator to a dead busbar (dead busbar closure function). When enabled, the M8100 Synchroscope
will give a close command to the generator breaker in case it detects that the busbar voltage is
below dead busbar voltage offset limit and the generator has reached at least 80% of its nominal
voltage. The busbar must be dead during the entire dead busbar delay time (this time delay is also
adjustable). The purpose of the dead busbar voltage offset is to give room for possible noise on the
busbar voltage input of M8100 Synchroscope.
Warning:
As this function could lead to short circuits (e.g. when more than one generator are
connecting to a dead busbar at the same time, this function should be treated carefully.
3
Connections
Before commissioning, make sure that the
phase sequences of generator and busbar
connections are correct.
