Chapter 3) 7SR242 Duobias Performance Specification
©2015 Siemens Protection Devices Limited
Chapter 3 Page 26 of 50
2.6 49 Thermal Overload
2.6.1 Reference
Parameter
Value
Is
Overload setting
0.10, 0.11… 3
xIn
Time constant setting
1, 1.5… 1000 min
2.6.2 Operate and Reset Level
Attribute
Value
I
ol
Overload level
100 %
Is
, 5 % or 1%
In
Reset level
95 %
I
ol
Repeatability
1 %
Variation
-10 °C to +55 °C
5 %
f
nom
- 3 Hz to
f
nom
+ 2 Hz
5 %
2.6.3 Operate and Reset Time
Attribute
Value
t
op
Overload trip operate time
2
2
2
P
2
I
I
I
ln
B
I
k
t
where
I
P
= prior current
5 % absolute or 100ms,
(Is: 0.3 – 3 x In)
Repeatability
100ms
Figure 2-1 shows the thermal curves for various time constants.
Summary of Contents for 7SR242 Duobias
Page 1: ...Answers for energy 7SR242 Duobias Transformer Protection Relay Reyrolle Protection Devices ...
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