Chapter 1) 7SR242 Duobias Description Of Operation
©2015 Siemens Protection Devices Limited
Chapter 1 Page 44 of 60
3.13 Voltage Protection: Under/Over Frequency (81)
Optionally six under/over frequency elements are provided.
Frequency elements are blocked if the measured voltage falls below the
81 U/V Guard
setting.
The sense of the element (under-frequency or over-frequency) is set by the
81-n Operation
setting.
81-n Setting
sets the pick-up frequency for the element.
An output is given after elapse of the
81-n Delay
setting.
The
81-n Hysteresis
setting allows the user to vary the pick-up/drop-off ratio for the element.
Operation of the under/over frequency elements can be inhibited from:
Inhibit 81-n
A binary or virtual input.
81-n U/V Guarded
Under voltage guard element.
User Inhibit
Reylogic (graphical logic).
Figure 3-20 Logic Diagram: Under/Over Frequency Detector (81)
Summary of Contents for 7SR242 Duobias
Page 1: ...Answers for energy 7SR242 Duobias Transformer Protection Relay Reyrolle Protection Devices ...
Page 2: ...2 ...
Page 4: ...4 ...
Page 6: ...6 www siemens com energy ...
Page 318: ... 2015 Siemens Protection Devices Limited Chapter 7 Page 2 of 64 ...
Page 324: ... 2015 Siemens Protection Devices Limited Chapter 7 Page 8 of 64 ...
Page 358: ... 2015 Siemens Protection Devices Limited Chapter 7 Page 42 of 64 ...
Page 366: ... 2015 Siemens Protection Devices Limited Chapter 7 Page 50 of 64 ...
Page 380: ... 2015 Siemens Protection Devices Limited Chapter 7 Page 64 of 64 ...
Page 381: ......