Siemens 7SR51 Device Manual page 254

Protection and Automation Functions
5.17 51 Time-Delayed Overcurrent – Phase
Parameter Value
Disabled
Enabled
Parameter: 51V Setting
•
Default setting: 30 V
This setting defines the operating voltage threshold of the element. When the phase to phase control
voltage is below this voltage setting the phase current settings of the 51-n elements on the affected
phase will be modified by the 51V Multiplier. The phase allocation of control voltages is as shown
below:
Current Element
I
A
I
B
I
C
If the voltage falls below setting when the 51-n element is picked up, the element does not reset and will
continue to time out towards operation at the 51V rate.
The voltage setting should be set to suit the individual application.
Parameter: 51V VTS Inhibit
•
Default setting: No
This setting defines the operating voltage threshold of the element. When the applied voltage is below
this setting the element will pickup.
The voltage setting should be set to suit the individual application.
Parameter: 51-n 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 Value
Disabled
Enabled
Parameter: 51‑n Measurement
•
Default setting: RMS
Selects whether fundamental frequency RMS or the true RMS value of the measured currents used.
254
Description
This element is switched out and is not available.
The element is available for use and can be parameterized.
Description
This element is switched out and is not available.
The element is available for use and can be parameterized.
Control Voltage
V
AB
V
BC
V
CA
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual
C53000-G7040-C014-1, Edition 11.2019