V-Protection Module – Voltage Protection [27/59]
V-Protection Module – Voltage Protection [27/59]
Available stages:
V[1] ,V[2] ,V[3] ,V[4]
If the VT measurement location is not at the bus bar side but at the output
side, the following has to be taken into account:
When disconnecting the line is it has to be ensured that by an
»External
Blocking«
undervoltage tripping of the U<-elements cannot happen. This is
realized through detecting of the CB position (via digital inputs).
When the aux. voltage is switched on and the measuring voltage has not
yet been applied, undervoltage tripping has to be prevented by an
»External Blocking«
In case of an fuse failure, it is important to block the
»U<-stages«
so that an
undesired operation can be prevented.
All 4 voltage elements are identically structured and can optionally be
projected as over-, undervoltage or time dependent (polygon) element.
If phase voltages are applied to the measuring inputs of the device and field
parameter
»VT con«
is set to
»Phase-to-neutral«
, the messages issued by
the voltage protection module in case of actuation or trip should be
interpreted as follows:
»V[1].A
LARM
L1« or »V[1].T
RIP
L1« => alarm or trip caused by phase voltage
»VL1«
.
»V[1].A
LARM
L2« or »V[1].T
RIP
L2« => alarm or trip caused by phase voltage
»VL2«
.
»V[1].A
LARM
L3« or »V[1].T
RIP
L3« => alarm or trip caused by phase voltage
»VL3«
.
If, however, line-to-line voltages are applied to the measuring inputs and
field parameter
»VT con«
is set to
»Phase to Phase«
, then the messages
should be interpreted as follows:
»V[1].A
LARM
L1« or »V[1].T
RIP
L1« => alarm or trip caused by line-to-line
voltage
»V12«
.
»V[1].A
LARM
L2« or »V[1].T
RIP
L2« => alarm or trip caused by line-to-line
voltage
»V23«
.
»V[1].A
LARM
L3« or »V[1].T
RIP
L3« => alarm or trip caused by line-to-line
voltage
»V31«
For each of the voltage protection stages it can be defined if it should be actuated in case over- or undervoltage
was detected in all three phases, or if it already should be alarmed when the over- or undervoltage was detected
in only one of the phases.
Page 236
EN MRU4 10/09
