Parameter: 79 Delayed Inhibit
•
Default setting: No
The autoreclose scheme sequence may require that some selected protection elements are only used for
the first trip(s) of the sequence, typically instantaneous ungraded protection elements, before reverting
to graded protection.
This setting is used to inhibit 50G operation when it is parameterized as instantaneous and only delayed
tripping is required. This should be selected to the default setting Off unless required by the autoreclose
sequence.
Parameter Value Description
No The earth fault element is normally active and is not
blocked by autoreclose sequence requirements.
Yes The 50G element will be inhibited from the autore-
close logic as required by the applied sequence. Incor-
rect 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 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
Functions > Function Config
Parameter Range Settings
Default Gn1 Gn2 Gn3 Gn4
50G Earth Fault Enabled
Disabled
Disabled
Functions > Protection > 50G > Gn 50G-n
Parameter Range Settings
Default Gn1 Gn2 Gn3 Gn4
Element Enabled
Disabled
Disabled
Measurement RMS
Fundamental
RMS
Dir. Control STET Non-Dir
Setting 0.005 to 2.5 I
rated
, Δ 0.005
I
rated
2.55 to 25 I
rated
, Δ 0.05 I
rated
0.5 ⋅
I
rated
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 s
VTS Action Off
Inhibit
Non-Dir
Off
5.13.5
Protection and Automation Functions
5.13 50G Instantaneous Earth Fault – Measured
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual 225
C53000-G7040-C014-1, Edition 11.2019
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