9
TGH1410en/03.2012
3. Function
3.1 Device features
AC and pulsed DC sensitive residual current monitor Type A according
to IEC 62020
Adjustable switching hysteresis
r.m.s. value measurement
Starting delay, response delay and delay on release
Measured value display via multi-functional LC display
Alarm indication via LEDs (AL1, AL2) and changeover contacts (K1, K2)
N/C operation or N/O operation selectable
Password protection against unauthorized parameter changing
Fault memory function can be switched off
CT connection monitoring
3.2 Function
Once the supply voltage U
s
is applied, the starting delay "t" is activated. Meas-
ured values exceeded during this time do not influence the switching state of
the alarm relays. Residual current monitoring takes place via an external
measuring current transformer. The currently measured value is shown on the
LC display. In this way any changes can be recognized easily, for example,
when circuits are connected to the system. If the measured value exceeds one
or both response values, the response delay t
on1/2
starts running. After the ex-
piry of the response delay t
on1/2,
the selected alarm relay switches and the
alarm LEDs light. If the release value is not reached before the expiry of t
on
, no
alarm will be signalled: the LEDs AL1, AL2 do not light and the alarm relays do
not switch. The set release time t
off
begins when the measured value again
falls below the release value (response value plus hysteresis) after the switch-
ing of the alarm relays. After the expiry of t
off,
the alarm relays switch back to
their initial position. With the fault memory activated, the alarm relays do not
change their actual state until the reset button R is pressed. The device func-
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