Reactor, Motor and Connections Protection
[dw_7SR5_function87Tsettingsexample17, 1, en_US]
Figure 5-69
AC Connections for Reactor and Connections Protection
Settings must take into consideration:
•
Connections: High internal and through fault currents.
•
Series reactor: Through fault current limited by reactor.
•
Shunt reactor: Single end fed faults only.
•
Motor: Single end fed faults only.
•
Generator: Single end fed faults only.
Primary current values are not subject to variation due to tap changing (as in transformer / OLTC applications),
the 87BD and 87BD 1st Bias Slope can both be set to 0.1.
The inrush inhibit feature (81HBL2) must be enabled as the magnetizing inrush currents in each phase will not
balance.
Settings Menu
Functions > Function Config
Parameter
Range
Settings
Default Gn1
Gn2
Gn3
Gn4
87T Transformer Diff
Enabled
Disabled
Disabled
Functions > Protection > 87T > Gn 87T Common
Parameter
Range
Settings
Default Gn1
Gn2
Gn3
Gn4
W1 ICT Multiplier
0.25 to 3 ⋅ I
rated
Δ 0.01
1x
W1 ICT Connection
Yy0
W2 ICT Multiplier
0.25 to 3 ⋅ I
rated
Δ 0.01
1x
W2 ICT Connection
Yy0
W3 ICT Multiplier
0.25 to 3 ⋅ I
rated
Δ 0.01
11
1x
5.22.5
11
7SR543 devices only
Protection and Automation Functions
5.22 87T Transformer Differential Protection
330
Reyrolle 7SR5, Transformer Protection Device, Device Manual
C53000-G7040-C015-1, Edition 11.2019