Logic Of The Function; Application And Setting Notes - Siemens 7SR51 Device Manual

Logic of the Function

5.24.3
[lo_7SR5_59Vxlogicdiagram, 1, en_US]
Figure 5-36
5.24.4

Application and Setting Notes

Parameter: Element
•
Default setting: Disabled
This setting is used to allow the element to be switched on and off if it is not required. A separate setting
is provided for each element. These settings can be used to select the number of elements required.
Parameter: Setting
•
Default setting: 80 V
This is the operating voltage threshold of the element. The element will pickup if the voltage falls below
this value. This should be set to suit the individual application.
Parameter: Hysteresis
•
Default setting: 3 %
This sets the drop-off threshold for the undervoltage element. The element will pickup if the voltage falls
below the setting and will reset when the voltage recovers to the setting + hysteresis voltage. This setting
is a percentage of the undervoltage setting.
The default setting of 3 % is generally enough to avoid chatter of the element but care may be required
for settings which are close to the nominal value otherwise the element may not reset when the voltage
recovers to nominal value as the voltage is still in the hysteresis window.
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual
C53000-G7040-C014-1, Edition 11.2019
Logic Diagram: 59Vx Overvoltage Protection – Vx
Protection and Automation Functions
5.24 59Vx Overvoltage Protection – Vx
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