Siemens 7SR51 - Settings Menu

•
Immunity to VT Fail
Both of these elements will be affected by VT failure if these settings are applied but a 3 phase VT fail
which would be required to affect the first stage may be less likely. In many cases it is preferable to
inhibit the voltage protection.
•
Any/All phases
The voltage control will operate on all 3 phases and the failure will result in voltage reduction on all 3
phases. The first stage should be set to operate on All phases. The second stage must operate for under-
voltage on Any phase.
Element Setting Values
27Vx Common UV Guard Setting 5 V
27Vx-1 Element Enabled
27Vx-1 Setting 99 V
27Vx-1 Hysteresis 3 %
27Vx-1 Delay 3 s
27Vx-1 UV Guarded Yes
27Vx-2 Element Enabled
27Vx-2 Setting 77 V
27Vx-2 Hysteresis 3 %
27Vx-2 Delay 1 s
27Vx-2 UV Guarded Yes
Settings Menu
Functions > Function Config
Parameter Range Settings
Default Gn1 Gn2 Gn3 Gn4
27Vx Undervoltage Enabled
Disabled
Disabled
Functions > Protection > 27Vx > Gn 27Vx Common
Parameter Range Settings
Default Gn1 Gn2 Gn3 Gn4
UV Guard Setting 1 to 200 V, Δ 0.5 V 5 V
Functions > Protection > 27Vx > Gn 27Vx-n
Parameter Range Settings
Default Gn1 Gn2 Gn3 Gn4
Element Enabled
Disabled
Disabled
Setting 5 to 200 V, Δ 0.5 V 80 V
Hysteresis 0 to 80 %, Δ 0.1 % 3 %
Delay 0 to 20 s Δ 0.01 s
20 to 100 s Δ 0.1 s
100 to 1000 s Δ 1 s
1000 to 10000 s Δ 10 s
10000 to 14400 s Δ 100 s
0.1 s
UV Guard Inhibit No
Yes
Yes
5.3.5
Protection and Automation Functions
5.3 27Vx Undervoltage Protection – Vx
160 Reyrolle 7SR5, Overcurrent Protection Device, Device Manual
C53000-G7040-C014-1, Edition 11.2019