Siemens 7SK80 - Settings

Functions
2.9 Thermal Overload Protection 49
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
162
Example:
Machine: I
Nom Mach
= 483 A
I
max Mach
=1.15 I
Nom
at Θ
K
= 40 °C
Θ
Nom Mach
= 93 °C Temperature at I
Nom Mach
τ
th
= 600 s (thermal time constant of the machine)
Current transformer: 500 A / 1 A
Motor Starting Recognition
The motor starting is detected when setting I MOTOR START at address 1107 is exceeded. Information on
how to perform the configuration is given under "Recognition of Running Condition (only for motors)" in
Subsection2.1.3.2.
2.9.3 Settings
Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings".
The table indicates region-specific default settings. Column C (configuration) indicates the corresponding sec-
ondary nominal current of the current transformer.
Addr. Parameter C Setting Options Default Setting Comments
4201 FCT 49 OFF
ON
Alarm Only
OFF 49 Thermal overload pro-
tection
4202 49 K-FACTOR 0.10 .. 4.00 1.10 49 K-Factor
4203 TIME CONSTANT 1.0 .. 999.9 min 100.0 min Time Constant
4204 49 Θ ALARM 50 .. 100 % 90 % 49 Thermal Alarm Stage
4205 I ALARM 1A 0.10 .. 4.00 A 1.00 A Current Overload Alarm
Setpoint
5A 0.50 .. 20.00 A 5.00 A
4207A Kτ-FACTOR 1.0 .. 10.0 1.0 Kt-FACTOR when motor
stops
4208A T EMERGENCY 10 .. 15000 sec 100 sec Emergency time
4209 49 TEMP. RISE I 40 .. 200 °C 100 °C 49 Temperature rise at
rated sec. curr.
4210 49 TEMP. RISE I 104 .. 392 °F 212 °F 49 Temperature rise at
rated sec. curr.