Specifications

7SR242 Duobias Description Of Operation
©2010 Siemens Protection Devices Limited Chapter 1 Page 24 of 52
c
Pickup
trip
87HS Setting
c
c
Pickup
trip
c
Pickup
trip
87HS ‘A’
Inhibit
87HS ‘B’
Inhibit
87HS ‘C’
Inhibit
General Pickup
87HS
W1-IL1
W1-IL2
W1-IL3
&
Inhibit 87HS
87HS Element
Enabled
Disabled
ICT
W1 ICT Multiplier
W1 ICT Connection
W2-IL1
W2-IL2
W2-IL3
ICT
W2 ICT Multiplier
W2 ICT Connection
87HS Delay
81HBL2 Element
Enabled
Disabled
Wn-IL1
Wn-IL2
Wn-IL3
81HBL2 Bias
L2 81HBL2
81HBL2 Setting
c
>
>
>
L1 81HBL2
L3 81HBL2
81HBL5 Element
Enabled
Disabled
Wn-IL1
Wn-IL2
Wn-IL3
81HBL5 Bias
81HBL5 Setting
c
>
>
>
87HS Inrush Action
Off
Inhibit
&
&
&
87HS ‘A’ Inhibit
87HS ‘B’ Inhibit
87HS ‘C’ Inhibit
L2 81HBL5
L1 81HBL5
L3 81HBL5
87HS Overfluxing Action
Off
Inhibit
&
&
&
87HS ‘A’ Inhibit
87HS ‘B’ Inhibit
87HS ‘C’ Inhibit
&
&
Figure 3-4 Logic Diagram: High Set Current Differential Protection