Siemens 7SR51 - Settings Menu

Parameter Value Description
Off 60VTS operation does not affect the element and the forward/reverse directional
decision assessed from the applied voltage is applied regardless of the 60VTS
state. During a VT failure the device may assess the direction incorrectly and the
element may operate for faults in the non-operate direction or not operate for
faults in the operate direction.
Inhibit When 60VTS detects a VT failure the element is immediately inhibited automati-
cally and will not operate. Tripping of a system fault will then rely on other
elements or devices.
Non-Dir When 60VTS detects a VT failure the element will become non-directional and
ignore the directional decision. The element will operate for overcurrent regard-
less of which direction the fault current is in.
Parameter: 79 Delayed Inhibit
•
Default setting: No
The autoreclose scheme can be designed such that only instantaneous elements are used for the first
trip(s) of the sequence before reverting to time graded protection. This setting allows the delayed
element to be inhibited during the delayed autoreclose shots and should be left at the default setting of
Off unless this is required.
Note that function elements are assigned as Delayed Trips in the 79 > 79GS menu.
Parameter Value Description
No The element is not inhibited by the autoreclose sequence design.
Yes The element will be inhibited during any autoreclose shot which is designated as
delayed. Incorrect configuration can result in no protection being enabled.
Settings Example
There should be little or no current flowing to earth in a healthy system so earth fault relays can be given far
lower pickup levels than relays which detect excess current above load current in each phase conductor. Earth
fault relays are important where the fault path to earth is a high-resistance one (such as in highly arid areas) or
where the system uses high values of earthing resistor/reactance as any earth fault current that flows in the
phase conductors will be limited.
Settings Menu
Configuration > Function Config
Parameter Setting Options Settings
Default Gn1 Gn2 Gn3 Gn4
50GS Sensitive Earth Fault Enabled
Disabled
Disabled
Functions > Protection > 50GS > Gn 50GS-n
Parameter Setting Options Settings
Default Gn1 Gn2 Gn3 Gn4
Element Enabled
Disabled
Disabled
Dir.Control
6
Non-Dir
Forward
Reverse
Non-Dir
5.14.5
6
Applies only to devices with VT inputs.
Protection and Automation Functions
5.14 50GS Instantaneous Sensitive Earth Fault – Measured
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual 231
C53000-G7040-C014-1, Edition 11.2019