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

3. Function

3.1 Features

ISOMETER® for AC IT systems with galvanically connected rectifiers or inverters and for DC
IT systems. (IT = unearthed systems)
• Automatic adjustment to high system leakage capacitances, for measuring ranges
see 11. "Alarm messages" on page 45
• Combination of AMP
PLUS
and other profile-specific measurement method
• Separately adjustable response values R
ing and alarm
• High-resolution graphic LC display for excellent readability and recording of the
device status
• Connection monitoring
• Automatic device self test with automatic alarm message in the event of a fault
• Graphical representation of the insulation resistance over time (isoGraph)
• History memory with real-time clock (buffer for 13 days) for storing 1023 alarm
messages with date and time
• Freely programmable digital inputs/outputs
• Remote setting of certain parameters via the Internet (COMTRAXX® gateway)
• Remote diagnosis by the Bender service via the Internet
• RS-485 interface for data exchange with other Bender devices
iso1685DP-425
• Measurement of insulation faults 200 Ω...1 MΩ
• Integrated locating current injector up to 50 mA for insulation fault location
• Display of insulation faults selectively located by EDS systems
• Parameter setting of EDS systems
• Customer-specific texts for each measuring channel via the menu
isoLR1685DP-425
• Measurement of low-resistance insulation faults 20 Ω...100 kΩ
• Integrated locating current injector up to 50 mA for insulation fault location
• Display of insulation faults selectively located by EDS systems
• Parameter setting of EDS systems
• Customer-specific texts for each measuring channel via the menu
isoHR1685D-925
• Measurement of high-resistance insulation faults 100 kΩ...100 MΩ
• Insulation monitoring for overhead catenary vehicles and elevating work platforms.
Observe application note "isoxx1685Dx-x25_D00272_00_N_XXDE" for this applica-
tion.
9
(alarm 1) and R (alarm 2) for prewarn-
an1 an2
Function

3.2 Product description

ISOMETER®s of the isoxx1685Dx-x25 device family are used for insulation monitoring of
large systems designed as IT systems. The device variants described in the manual have
different voltage ranges. The exact device specification can be found in
nical data.
The measurement method especially developed for this purpose monitors the insulation
resistance even in installations where extremely high system leakage capacitances
against earth exist due to interference suppression methods. Adaptation even to system-
related high leakage capacitances is automatic.
The ISOMETER®s isoxx1685DP-x25 generate locating current pulses required for insula-
tion fault location. That allows the localisation of the insulation fault using permanently
installed or mobile insulation fault locators.

3.3 Functional 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. If the insulation resistance
between the IT system and earth falls below the set prewarning response value R
"ALARM 1" LED lights up and relay K1 (11/12/14) switches. If the insulation resistance falls
below the alarm response value R , alarm relay K2 (21/22/24) switches and the "ALARM
an2
2" LED lights up.
When starting the insulation fault location, the "PGH ON" LED signals the locating current
pulse.

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
Pulse sequence of the measuring voltage for insulation fault monitoring
Chapter 12. Tech-
, the
an1
t
isoxx1685Dx-x25_D00272_06_M_XXEN/04.2020