Specifications

7SR242 Duobias Applications Guide
Summary of Required Settings
CT/VT CONFIG >
W1 Phase Input 1A
W1 Phase CT Ratio 400:1
W2 Phase Input 1A
W2 Phase CT Ratio 1600:1
FUNCTION CONFIG>
Gn Differential Enabled
Gn Inrush Detector Enabled
DIFFERENTIAL PROT’N >
Gn W1 ICT Multiplier 1.02
Gn W1 ICT Connection Yd11
Gn W2 ICT Multiplier 1.07
Gn W2 ICT Connection Yy0
(Note that the above settings produce ICT
OUT
= 1.00)
DIFFERENTIAL PROT’N > 87BD >
Gn 87 BD Element Enabled
Gn 87BD Initial: 0.3 x In (0.3 x ICT
OUT
)
Gn 87BD 1st Bias Slope: 0.3x (OLTC = +10% to -20%)
Gn 87BD 1st Bias Slope Limit: 4 x In (1/0.14 x 0.5 = 3.6 x ICT
OUT
)
Gn 87BD 2nd Bias Slope Type: Line (Default value)
Gn 87BD 2nd Bias Slope: 1.5x (Default value)
Gn 87BD Delay: 0.005s
Gn 87BD Inrush Action: Inhibit
Gn 87BD Overfluxing Action: Off
DIFFERENTIAL PROT’N > 87HS >
Gn 87HS Element Enabled
Gn 87HS Setting: 8 x In (> I
3PH THRU FAULT
i.e. 1/0.14 = 7.14 x ICT
OUT
)
Gn 87HS Delay: 0.005s
Gn 87HS Inrush Action: Off
Gn 87HS Overfluxing Action: Off
SUPERVISION > INRUSH DETECTOR >
Gn81HBL2 Element Enabled
Gn 81HBL2 Bias Cross (Default value)
Gn 81HBL2 Setting 0.2 x I (Default value)
OUTPUT CONFIG>OUTPUT MATRIX>
87BD BOn, Ln
87HS BOn, Ln
OUTPUT CONFIG>BINARY OUTPUT CONFIG>
CB1 Trip Contacts BOn
CB2 Trip Contacts BOn
©2010 Siemens Protection Devices Limited Chapter 7 Page 18 of 56