Thermal Overload Protection 49 - Siemens siprotec SJ62 User Manual

4.14

Thermal Overload Protection 49

Setting Ranges / Increments
Trip Characteristic
Dropout Ratios
Tolerances
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
K-Factor per IEC 60255-8
Time Constant τ
th
Thermal Alarm Θ
/Θ
Alarm Trip
Current Overload I
Alarm
Extension kτ Factor when Machine
Stopped
Emergency Time T
Emergency
Nominal Overtemperature (for I
Θ/Θ
Trip
Θ/Θ
Alarm
I/I
Alarm
Referring to k · I
Nom
Referring to Trip Time
4.14 Thermal Overload Protection 49
0.10 to 4.00
1.0 min to 999.9 min
50% to 100% of the trip ex-
cessive temperature
for I = 0.10 A to 4.00 A
Nom
1 A
for I = 0.50 A to 20.00 A
Nom
5 A
1.0 to 10.0 relative to the
time constant for the
machine running
10 s to 15000 s
40 °C to 200 °C = –13 °F to
)
Nom
+185 °F
Drops out with Θ
Approx. 0.99
Approx. 0.97
2 % or 10 mA for I
5 A,
2 % class according to IEC 60255-8
3 % or 1 s for I/(k ·I
3 % class according to IEC 60255-8
Increments 0.01
Increments 0.1 min
Increments 1 %
Increments 0.01 A
Increments 0.1
Increments 1 s
Increments 1 °C
Alarm
= 1 A, or 50 mA for I
Nom
) > 1.25;
Nom
=
Nom
490