Functions
2.9 Thermal Overload Protection 49
Example:
Machine: I
Nom Mach
=1.15 I
I
max Mach
Θ
= 93 °C Temperature at I
Nom Mach
τ
= 600 s (thermal time constant of the machine)
th
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
4201
FCT 49
4202
49 K-FACTOR
4203
TIME CONSTANT
49 Θ ALARM
4204
4205
I ALARM
4207A
Kτ-FACTOR
4208A
T EMERGENCY
4209
49 TEMP. RISE I
4210
49 TEMP. RISE I
162
= 483 A
at Θ
= 40 °C
Nom
K
Nom Mach
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
1.0 .. 10.0
10 .. 15000 sec
40 .. 200 °C
104 .. 392 °F
Default Setting
OFF
49 Thermal overload pro-
tection
1.10
49 K-Factor
100.0 min
Time Constant
90 %
49 Thermal Alarm Stage
1.00 A
Current Overload Alarm
Setpoint
5.00 A
1.0
Kt-FACTOR when motor
stops
100 sec
Emergency time
100 °C
49 Temperature rise at
rated sec. curr.
212 °F
49 Temperature rise at
rated sec. curr.
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
Comments