Bender B 7301 0020, Руководство по эксплуатации

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Function
10 TGH1444en/04.2011
3.2 Function
Once the supply voltage is applied, the start-up delay plus response delay (t +
t
on1/2
) begins. Throughout this time, an alarm is output via alarm LEDs and re-
lays. Measured voltage and frequency values being changed during this start-
up period t do not influence the alarm LEDs and the state of the alarm relays.
The devices utilise several separately adjustable measuring channels (over-
voltage/undervoltage, overfrequency/underfrequency). When the measured
value exceeds or falls below the response value, the alarm relays switch and
the alarm LEDs light up. When the measured value exceeds or falls below the
release value (response value plus hysteresis) after the alarm relays have
switched, the selected release delay t
off
begins. When t
off
has elapsed, the
alarm relays switch back to their initial position. With the fault memory acti-
vated, the alarm relays do not change their actual state until the reset button
R is pressed.
3.2.1 Calculating the average value of overvoltage
The overvoltage U2 is determined by calculating an average value of the last
10-minute measuring interval.
Always the highest average value U2 of each of the three voltages monitored
between L1-N, L2-N, L3-N will be indicated.
3.2.2 Automatic self test
The device automatically carries out a self test after connection to the system
to be monitored and later every hour. During the self test internal functional
faults are detected and will appear in form of an error code on the display. The
alarm relays are not tested during this time.
3.2.3 Manual self test
Pressing the test button for > 1.5 s causes the device to carry out a self test
where the internal functional errors are determined and shown on the display
as error codes. The alarm relays are not tested during this time.
While the test button T is pressed and held down, all device-related display el-
ements appear on the display.