ISO685-D-B Bender

Product description
The ISOMETER® is an insulation monitoring devices in accordance with IEC 61557-8 for 
IT systems. The devices are universally applicable in AC, 3(N)AC, AC/DC and DC systems. 
AC systems may include extensive DC-supplied loads (such as rectifiers, inverters, variablespeed
 drives).
Application
Function
The insulation monitoring device continuously monitors the entire insulation resistance 
of an IT system during operation and triggers an alarm when the value falls below a preset 
response value. To obtain a measurement the device has to be connected between the IT 
system (unearthed system) and the protective earth conductor (PE). A measuring current 
in the μA range is superimposed onto the system which is recorded and evaluated by a 
microprocessor-controlled measuring circuit. The measuring time is dependent on the 
selected measurement profiles, the system leakage capacitance, the insulation resistance 
and possible system-related disturbances.
The response values and other parameters are set using a commissioning wizard as well 
as via different setup menus using the device buttons and a high-resolution graphical LC 
display. The selected settings are stored in a permanent fail-safe memory. Different languages 
can be selected for the setup menus as well as the messages indicated on the display. 
The device utilises a clock for storing fault messages and events in a history memory with 
time and date stamp. The settings can be password protected to prevent unauthorised 
changes.
To ensure proper functioning of connection monitoring, the device requires the setting of the 
system type 3AC, AC or DC and the required use of the appropriate terminals L1/+, L2, L3/-.
The insulation monitoring device iso685–x–B is able to measure the insulation resistance 
reliably and precisely in all common IT systems (unearthed systems). Due to various applications,
 system types, operating conditions, application of variable-speed drives, high 
system leakage capacitances etc., the measurement technique must be able to meet varying 
requirements in order to ensure an optimised response time and relative uncertainty. 
Therefore different measuring profiles can be selected with which the device can optimally 
adjusted.
If the preset response value falls below the value of Alarm 1 and/or Alarm 2, the associated 
alarm relays switch, the LEDs ALARM 1 or ALARM 2 light and the measured value is shown 
on the LC display (in case of insulation faults in DC systems, a trend graph for the faulty 
conductor L+/L- is displayed). If the fault memory is activated, the fault message will be 
stored. Pressing the RESET button resets the insulation fault message, provided that the 
current insulation resistance displayed at the time of resetting is at least 25 % above the 
actual response value. As additional Information, the quality of the measuring signal and 
the time required to update the measured value are shown on the display. A poor signal 
quality (1-2 bars) may be an indication that the wrong measurement profile has been 
selected.
The ISOMETER® has an internal system isolating switch, which makes it possible to operate 
several ISOMETER®s in coupled IT systems. For this purpose, the ISOMETER®s are connected 
via an Ethernet bus. The integrated ISOnet function ensures that only one ISOMETER® is 
actively measuring at a time, while the other devices are completely isolated from the system 
and waiting in standby mode for measuring permission.
The ISOMETER® is able to synchronise itself with other ISOMETER®s. This makes it possible 
to monitor capacitive coupled IT systems without interfering with each other.
Device features 
• ISOMETER® for IT AC systems with galvanically
 connected rectifiers or inverters and 
for IT DC systems (IT = unearthed systems)
• Automatic adaptation to the existing 
system leakage capacitance
• Combination of AMPPlus
 and other profilespecific
 measurement methods
• Two separately adjustable response value 
ranges of 1 kΩ…10 MΩ
• High-resolution graphic LC display for excellent
 readability and recording of the 
device status
• Connection monitoring (monitoring of 
the measuring lines)
• Automatic device self test
• Graphical representation of the insulation 
resistance over time (isoGraph)
• History memory with real-time clock (buffer
 for three days) for storing 1023 alarm 
messages with date and time
• Current or voltage output 0(4)…20 mA, 
0…400 μA, 0…10 V, 2…10 V (galvanically 
separated), which is analogous to the 
measured insulation value of the system
• Freely programmable digital inputs and 
outputs
• Remote setting via the Internet or 
Intranet (Webserver/Option: COMTRAXX® 
Gateway).
• Worldwide remote diagnosis via the 
Internet
• RS-485/BS (Bender sensor bus) for communication
 with other Bender devices
• ISOnet: Internal separation of the ISOMETER® 
from the IT system to be monitored (e.g. 
if several IT systems are interconnected)
• BCOM, Modbus TCP/RTU and web server
• Voltage expandable via coupling devices