Product Description; Function Description - Bender ISOMETER iso1685DP-425 Manual

3. Function
3.1 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 and other profile-specific measurement methods
• Two separately adjustable response value ranges of 1 kΩ...10 MΩ for Alarm 1 and
Alarm 2
• Hgh-resolution graphical LC display
• 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
• Freely programmable digital inputs and outputs
• Remote setting via the Internet or Intranet (COMTRAXX® gateway)
• Worldwide remote diagnosis via the Internet (made available by Bender Service
only)
• RS-485 interface for data exchange to other Bender devices
iso1685DP-425
• measuring insulation faults 200Ω...1MΩ
isoLR1685DP-325
• Measunring insulationfaults 20Ω...100kΩ
isoHV1685DP-425
• measuring insulation faults 200Ω...1MΩ at mains voltages AC 2000V, DC 3000 V
iso1685DP-425 and isoLR1685DP-325
• Locating current injection for selective insulation fault location
• Indication of the insulation faults selectively located by the EDS system
• Parameter setting of EDS systems
• Customer-specific texts for each measuring channel
10
Function

3.2 Product description

The ISOMETER® isoxx1685Dx-x25 is used for insulation monitoring of extensive IT sys-
tems . The specially developed measurement method monitors the insulation resistance
also in installations where extremely high system leakage capacitances against earth ex-
ist due to interference suppression methods. Adaptation to system-related high leakage
capacitances also occurs automatically.
The ISOMETER® iso1685Dxx generates locating current pulses required for insulation
fault location. That allows the localisation of the insulation fault using permanently in-
stalled or mobile insulation fault locators.

3.3 Function description

Insulation monitoring is carried out using an active measuring pulse which is superim-
posed onto the IT system to earth via the integrated coupling. When the insulation resist-
ance between the IT system and earth falls below the set prewarning response value
R 1, the "ALARM 1" LED lights and the relay K1 (11/12/14) switches. When the insulation
an
resistance falls below the alarm response value R
es and the "ALARM 2" LED lights.
The locating current injector integrated in the device for insulation fault location is acti-
vated externally via the BMS interface. When starting the insulation fault location, the LED
"PGH ON" signals the locating current pulse.
The ISOMETER® cannot take over the master function. If there is no master in the system,
the device can act as a backup master and communicate with the slaves in the system.
3.3.1 Insulation monitoring
For insulation monitoring, a pulsating AC measuring voltage is superimposed onto the IT
system. The measuring pulse consists of positive and negative rectangular impulses of
the same amplitude. The period duration depends on the system leakage capacitances in
each case and the insulation resistances of the system to be monitored.
U
m
Pic. 3.1: Pulse sequence of the measuring voltage for insulation fault monitoring
2, the alarm relay K2 (21/22/24) switch-
an
t
isoxx1685Dx-x25_D00272_05_M_XXEN/04.2018