Setting Notes - Siemens siprotec SJ62 User Manual

2 Functions
2.6.4

Setting Notes

General
Overvoltage Pro-
tection with Phase
Voltages
141
Voltage protection is only in effect and accessible if address 150 27/59 is set to
Enabled during configuration of protective functions. If the fuction is not required,
Disabled is set.
The setting values refer to phase-phase voltages with three-phase voltage transform-
er connection and also with connection of only one phase-phase voltage if the evalu-
ation quantity for overvoltage protection was configured to phase-phase voltage at
address 614 OP. QUANTITY 59. They must be set as phase-to-ground voltages if
this parameter is configured to negative-sequence voltage V2.
In case of a single-phase connection of a phase-to-ground voltage, the threshold
values must be set as phase-to-ground voltages. The setting ranges depend on the
type of voltage transformer connection utilized (specified at address 213 VT
Connect. 3ph, three phase-to-ground voltages or two phase-to-phase voltages).
For voltage transformers connected in a ground-wye configuration, higher setting
values may be used because the voltage inputs are subjected only to phase-to-ground
voltage levels.
Overvoltage protection can be turned ON or OFF, or set to Alarm Only at address
5001 FCT 59.
Undervoltage protection can be turned ON, OFF, or Alarm Only at address 5101 FCT
27.
With the protection functions activated (ON), tripping, the opening of a fault and fault
recording are initiated when the thresholds are exceeded and the set time delays have
expired.
With setting Alarm Only no trip command is given, no fault is recorded and no spon-
taneous fault annunciation is shown on the display.
The largest of the voltages applied is evaluated for the phase-to-phase or phase-to-
ground overvoltage protection. With three-phase connection as well as with single-
phase connection of a phase-to-phase voltage the threshold is set as a phase-to-
phase quantity. With single phase-to-ground connection the threshold is set as phase–
to–ground voltage.
Overvoltage protection includes two elements. The pickup value of the lower threshold
is set at address 5002 or 5003, 59-1 PICKUP (depending on if the phase-to-ground
or the phase-to-phase voltages are connected), while time delay is set at address
5004, 59-1 DELAY (a longer time delay ). The pickup value of the upper element is
set at address 5005 or 5006, 59-2 PICKUP, while the time delay is set at address
5007,59-2 DELAY (a short time delay). There are no clear cut procedures on how to
set the pickup values. However, since the overvoltage function is primarily intended to
prevent insulation damage on equipment and users, the setting value 5002 or 5003
59-1 PICKUP should be set between 110% and 115% of nominal voltage, and setting
value 5005 or 5006 59-2 PICKUP should be set to about 130% of nominal voltage.
Addresses 5002 and 5005 can be accessed if phase-to-ground voltages are connect-
ed to 7SJ62/63/64, whereas addresses 5003 and 5006 can be accessed if phase-to-
phase voltages are connected. The time delays of the overvoltage elements are
entered at addresses 5004 59-1 DELAY and 5007 59-2 DELAY and should be se-
lected to allow the brief voltage spikes that are generated during switching operations
and to enable clearance of stationary overvoltages in time.
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015