Siemens SIPROTEC 7SK80 - Thermal Overload Protection 49

Technical Data
4.14 Thermal Overload Protection 49
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A4, Release date 08.2010
374
4.14 Thermal Overload Protection 49
Setting Ranges / Increments
Trip Characteristic
Dropout Ratios
Tolerances
Influencing Variables Referring to k · I
Nom
K-Factor per IEC 60255-8 0.10 to 4.00 Increments 0.01
Time Constant τ
th
1.0 min to 999.9 min Increments 0.1 min
Thermal Alarm Θ
Alarm
/Θ
Trip
50% to 100% of the trip excessive
temperature
Increments 1 %
Current Overload I
Alarm
for I
Nom
= 1 A 0.10 A to 4.00 A Increments 0.01 A
for I
Nom
= 5 A 0.50 A to 20.00 A
Extension kτ Factor when Machine
Stopped
1.0 to 10.0 relative to the time constant for
the machine running
Increments 0.1
Emergency Time T
Emergency
10 s to 15000 s Increments 1 s
Nominal Overtemperature (for I
Nom
) 40 °C to 200 °C = –13 °F to +185 °F Increments 1 °C
Θ/Θ
Trip
Θ/Θ
Alarm
I/I
Alarm
Drops out with Θ
Alarm
Approx. 0.99
Approx. 0.97
Referring to k · I
Nom
Referring to trip time
3 % or 15 mA for I
Nom
= 1 A, or 75 mA for I
Nom
= 5 A,
2 % class according to IEC 60255-8
3% or 1s for I/(k ·I
Nom
) > 1.25;
3 % class according to IEC 60255-8
Auxiliary DC voltage in range
0,8 ≤ V
Aux
/V
AuxNom
≤ 1.15
1%
Temperature in range –5 °C (41 °F) ≤ Θ
amb
≤ 55 °C (131 °F) 0.5 %/10 K
Frequency in range of 50 Hz to 70 Hz
Frequency in range 0.95 ≤ f/f
Nom
≤ 1.05 1 %
Frequency outside range 0.95 ≤ f/f
Nom
≤ 1.05 Increased tolerances