Suppression Of Switching Operations; Reset; Indication Of The Continuous Earth-Fault Only In Forward Direction; Figure 2.3 Adjusting Elements - Siemens 7SN71 Instruction Manual

2
Method of operation
Transient earth-fault relay 7SN71
2.4

Suppression of switching operations

The front plug t " is used to enable or disable the
v
delay time for control of the displacement voltage
once a directional indication has been effected
through earth faults or switching operations.
2.5

Reset

Indications and signals can be reset
D by pressing the Reset" button on the front plate
D via the remote reset with 24 to 250 V
D automatically by opening jumper S8 (position as
delivered: closed). Indication and signalling of the
transient earth-fault direction is reset approx. 3 s
after the earth fault has disappeared.
2.6

Indication of the continuous earth-fault only in forward direction

If jumper S7 is opened (position as deliverd: closed),
occurrances of continuous earth faults will only be
indicated in forward direction (tripping contact !)
Trimming pot.
Figure 2.3 Adjusting elements
2 - 4
Instruction Manual Order No.: E50410-A0007-U501-A1-7691
If the front plug t
in isolated systems are not indicated or signalled.
In compensated systems, the plug should always be
withdrawn.
IC
Jumpers S7 + S8 (Dip-Fix)
Printed board cutout: top view
" is inserted, switching operations
v
Caution!
Electrostatic discharges via the
component connections, the PCB
tracks or the connecting pins of the
modules must be avoided under all
circumstances by previously tou
ching an earthed metal surface.
Caution!
Electrostatic discharges via the
component connections, the PCB
tracks or the connecting pins of the
modules must be avoided under all
circumstances by previously tou
ching an earthed metal surface.
Front panel
Capacitors
Siemens AG March 1997