IRDH275BM-7_D00123_07_M_XXEN / 08/2020 11
ISOMETER® IRDH275BM-7
During operation, the self test function can be started by pressing the TEST button (internal or external).
The self test can also be started automatically every hour or every 24 hours by selecting „ISO
ADVANCED: Autotest“ menu. The alarm relays Alarm1/2 only switch after starting the self test function
by pressing the TEST button, that means if an automatic self test has been selected, the alarm relays do
not switch.
Alarmmeldung
Beschreibung
Maßnahmen
Connection PE?
No low-resistance connection of
the terminals
and KE to earth
(PE)
1. Check wiring of terminal
and KE to earth (PE)
2. Press TEST button
3. Switch the supply voltage off and on
Device error x
Internal device error
1. Press TEST button
2. Switch the supply voltage off and on
3. Contact Bender
i
If the on/off switching of the supply voltage is not possible for technical reasons, a RESET of the pro-
cess control can be carried out by pressing the „ESC“, „RESET“ and „MENU“ key.
Current output for external measuring instrument
The current output of the ISOMETER® provides 0(4)…20 mA. The current output is galvanically isolated
from the device electronics and the RS-485 interface. The
menu allows to switch over bet-
ween 0…20 mA and 4…20 mA.
Real-time clock
The real-time clock serves as a time base for the memory and self test functions. At first, the correct
time and date must be set in the menu „ISO ADVANCED“. If time and date are not set, a „C“ (clock) is
flashing in the standard display. In the event of a supply voltage failure, time and date will be stored for
at least thirty days.
If the 24 V test is activated in the „ISO ADVANCED“ menu, a special time of day can be selected for the
execution of the self test in the menu „TEST: 12:00“. Then a self test will be started automatically once a
day exactly at the preset time. If the 1 h auto test has been selected, the self test is automatically carried
out every full hour.
Function input F1/F2 to switch over to the standby mode
When the input terminals F1/F2 are bridged, the measuring function is stopped and the message
„STANDBY“ appears on the display. The currently measured value is blanked and the value > 10 MΩ is
indicated. The alarm relays and alarm LEDs no longer provide alarm messages. After opening the functi-
on input F1/F2, a completely new measuring cycle for insulation monitoring is started.
