Voltage Ring Buffer - Horstmann ComPass B Instructions For Use Manual

Instructions for Use
• Isolated network operation (sinφ)
In networks with isolated neutral, the ComPass B determines the direction of the reactive
power of the earth fault current (V
3.1.3.

Voltage ring buffer

If there is a small distance between the location of the fault and the place of installation of the
ComPass B unit, the phase voltages of the affected phases may become too small to be usefull for
the decision of fault direction. For this reason, the Compass B is provided with a ring buffer. The
measured values of all phase voltages are permanently written into this buffer. In case of a fault
these voltages are extrapolated in time in order to obtain information on the phase relation.
3.1.4. Inrush current suppression
The ComPass B uses an inrush current suppression to avoid unintended tripping due to inrush. The
ComPass B can be adjusted such as to detect faults only when the phase voltages were previously
present for a preset time.
This function is deactivated in delivery status!
3.1.5. Fault indication
Faults are indicated locally by the multicolour LED and the OLED display, and remotely indicated
via the RS485/MODBUS interface/relays.
• Multicolour LED
The multicolour LED flashes red as long as ComPass B is indicating a fault.
• OLED display
In case of a fault, the OLED display presents a fault message informing on the type and di-
rection of the fault. For indication press any direction on the rocker switch.
8
× I × sin φ).
NE E
Figure 11: Angle diagram
Dipl.-Ing. H. Horstmann GmbH
V
NE
ComPass B 4023841-001