8
iso415R-x_D00401_00_M_XXEN / 04.2021
Function
2
Function
2.1
Device features
• Monitoring of the insulation resistance for unearthed 3(N)AC, AC and DC systems with galvani-
cally connected rectifiers
• Automatic adaptation to the system leakage capacitance up to 25 μF
• Response time ≤ 6 s at C
e
= 1µF and R
f
= Ran/2
• Automatic device self test with connection monitoring
• Two separately adjustable response value ranges from 5 kΩ…1000 kΩ
• Alarms are output via LEDs (AL1, AL2) and an alarm relay
• Selectable N/C or N/O relay operation
1
• Selectable start-up delay, response delay and delay on release
1
• Fault memory
1
• RS-485 interface with Modbus RTU protocol
• NFC interface
2.2
Device-specific instructions
i
Operation inside a control cabinet.
Device signals must be visually perceptible outside the control cabinet.
i
IT systems with several ISOMETER®s.
Only one ISOMETER® may be installed in a galvanically connected system. In IT sys-
tems that are interconnected via coupling switches, ISOMETER®s that are not re-
quired must be disconnected from the IT system or deactivated. If IT systems are
coupled via capacitances or diodes, central control of the various ISOMETER®s must
be provided.
i
Prevent measurement errors!
In galvanically coupled DC circuits, an insulation fault can only be detected correctly
if a minimum current of > 10 mA flows through the rectifiers.
2.3
Functional description
The iso415R is used to monitor the insulation fault
F
and to determine its location in unearthed
systems. In addition to the limit value comparison, functions for connection monitoring, detection
of device-internal errors and exceeding the maximum permissible leakage capacitance C
e
are
available.
The measured value R
F
as well as all messages and alarms are displayed via the LEDs on the con-
trol panel and can be read out via the interfaces (Modbus RTU and NFC). Furthermore, the mes-
sages and alarms are also output via relay K1, depending on the alarm assignments that can be
set via the interfaces.
1 with app and Modbus RTU
