Settings; Information List - Siemens SIPROTEC 7SD610 Manual

Functions
2.14 Thermal Overload Protection
Calculating the overtemperature
The thermal replica is calculated individually for each phase. Address 4206 CALC. METHOD decides whether
the highest of the three calculated temperatures (Θ max) or their arithmetic average (Average Θ) or the tem-
perature calculated from the phase with maximum current (Θ from Imax) should be decisive for the thermal
alarm and tripping stage.
Since overload is usually a symmetrical process, this setting is of minor importance. If asymmetrical overloads
are to be expected, however, these options lead to different results.
Averaging should only be used if a rapid thermal equilibrium is possible in the protected object, e.g. with belted
cables. If the three phases are, however, more or less thermally isolated (e.g. single conductor cables or over-
head lines), one of the maximum settings should be chosen at any rate.
2.14.3

Settings

The table indicates region-specific presettings. Column C (configuration) indicates the corresponding second-
ary nominal current of the current transformer.
Addr. Parameter
4201 Ther. OVERLOAD
4202 K-FACTOR
4203 TIME CONSTANT
4204 Θ ALARM
4205 I ALARM
4206 CALC. METHOD
2.14.4

Information List

No. Information
1503 >BLK ThOverload
1511 Th.Overload OFF
1512 Th.Overload BLK
1513 Th.O/L ACTIVE
1515 Th.O/L I Alarm
1516 Th.O/L Θ Alarm
1517 Th.O/L Pickup
1521 Th.O/L TRIP
198
C Setting Options
OFF
ON
Alarm Only
0.10 .. 4.00
1.0 .. 999.9 min
50 .. 100 %
1A 0.10 .. 4.00 A
5A 0.50 .. 20.00 A
Θ max
Average Θ
Θ from Imax
Type of In-
formation
SP >BLOCK Thermal Overload Protection
OUT Thermal Overload Protection OFF
OUT Thermal Overload Protection BLOCKED
OUT Thermal Overload Protection ACTIVE
OUT Th. Overload: Current Alarm (I alarm)
OUT Th. Overload Alarm: Near Thermal Trip
OUT Th. Overload Pickup before trip
OUT Th. Overload TRIP command
Default Setting
OFF Thermal overload protec-
tion
1.10 K-Factor
100.0 min Time Constant
90 % Thermal Alarm Stage
1.00 A Current Overload Alarm
Setpoint
5.00 A
Θ max Method of Acquiring Tem-
perature
Comments
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
Comments