Function
16
isoEV425_D00126_09_M_XXEN/03.2019
If the values
R
F
or
U
n
do not violate their release value (response value plus
hysteresis) for the period
t
off
without interruption, the alarm relays will switch
back to their initial position and the alarm LEDs "AL1"/"AL2" stop lighting. If
the fault memory is activated, the alarm relays remain in alarm condition and
the LEDs light until the reset button "R" is pressed or the supply voltage
U
s
is
interrupted.
The device function can be tested using the test button "T". Parameters are as-
signed to the device via the LCD and the control buttons on the front panel;
this function can be password-protected. Parameterisation is also possible via
the BMS bus, for example by using the BMS Ethernet gateway (COM465IP) or
the Modbus RTU.
3.2.1
Monitoring the insulation resistance
The two parameters that monitor the insulation resistance, R1 and R2, can be
found in the response value menu "AL" (see table in
). The value R1
can only be set higher than the value R2. If the insulation resistance
R
F
reaches
or falls below the activated values R1 or R2, an alarm message will be sig-
nalled. If
R
F
exceeds the values R1 or R2 plus the hysteresis value (see table in
), the alarm will be cleared.
3.2.2
Undervoltage/overvoltage monitoring
In the response value menu "AL" (see
), the parameters
("U <" and "U >") for monitoring the mains voltage can be activated or deacti-
vated. The maximum undervoltage value is limited by the overvoltage value.
The r.m.s. value of the nominal system voltage
U
n
is monitored. If the nominal
system voltage
U
n
reaches, falls below or exceeds the limit values ("U <" or
"U >"), an alarm will be signalled. If the maximum permissible nominal system
voltage
U
n
set for the ISOMETER® is exceeded, an alarm message will be initi-
ated even when the overvoltage limit value has been deactivated. The alarm
will be deleted when the limit values plus hysteresis
) are no
longer violated.