User Manual M8100
M8196-72E
Page 5 of 7
The highest tolerance is adjusted by turning the potentiometer P1 clockwise until end position.
Then the limits are as follows:
∆U = 20%
∆f = 0,3Hz
∆φ = 12
◦
4.2
Dead bus closure
This function enables the built-in check synchronizer relay to close the circuit breaker even though
there is no voltage on the busbar. The generator voltage must be at least at 80% of the nominal
voltage before the dead bus closure can activate.
For activating the dead bus closure, terminals 9 and 10 must be bridged.
4.2.1
Voltage Offset
The purpose of the dead busbar voltage offset is to give room for possible noise on the busbar
voltage input of M8100 Synchroscope.
The M8100 Synchroscope considers the busbar to be dead in case the busbar voltage is below the
dead busbar voltage offset. This offset can be adjusted by potentiometer P2. The range is between
20% of nominal voltage to 40% of nominal voltage.
Turning P2 counter clockwise until end position means 20%.
Turning P2 clockwise until end position means 40%.
4.2.2
Dead busbar delay time
The dead bus closure facility will only close the breaker to the dead busbar in case the busbar
voltage has been below the voltage offset limit during the entire time delay. This time delay can be
adjusted by potentiometer P3.
Turning P3 counter clockwise to end position: delay = 1s
Turning P3 clockwise to end position: delay = 5s
