Bender IR425-D4-2 B71036402 データシート

42 

TDB103005en / Main catalogue part 1 – Insulation monitoring / 09.2011  

Dipl.-Ing. W. Bender GmbH & Co. KG • Londorfer Str. 65 • 35305 Grünberg • Tel.: 06401 807-0 • Fax: 06401 807-259

 

Subject to change! – © Dipl.-Ing. W. Bender GmbH & Co. KG, Germany

•   Insulation monitoring for control circuits 

AC/DC 0…300 V

•  Two separately adjustable response values

•  

Preset function
(automatic assignment of basic parameters)

•  Connection monitoring system / earth

•  LEDs: Power On, Alarm 1, Alarm 2

•  Internal/external test/reset button

•  Two separate alarm relays
  (one changeover contact each)

•  N / O or N / C operation, selectable

•  Fault memory behaviour, selectable

•  Self monitoring with automatic alarm

•  Multi-functional LC display

•  Adjustable response delay

•  Two-module enclosure (36 mm)

•  

Push-wire terminal
(two terminals per connection)

  

  

The A-ISOMETER®s of the IR425 series monitor the insulation resistance of unearthed AC / DC 
control circuits (IT systems) 0…300 V. DC components existing in AC/DC systems do not 
influence the operating characteristics. An external supply voltage allows de-energised 
systems to be monitored too.

•   AC/DC control circuits in the industrial sector, mechanical engineering, power plants, 

elevators, automation systems etc.

•   AC / DC control and auxiliary circuits acc. to IEC 60204-1: "Safety of machinery – 

Electrical equipment of machines, Part 1: General requirements" 

•  Smaller AC/DC IT systems such as lighting systems

The currently measured insulation resistance is indicated on the LC display. In this way 
any changes, for example when circuits are connected to the system, can be recognised 
easily. When the value falls below the preset response values, the response delay "t

on

" 

starts. Once the response delay "t

on

" has elapsed, the alarm relays "K1 / K2" switch and 

the alarm LEDs "AL1 / AL2" light up. Two separately adjustable response values/alarm relays 
allow a distinction to be made between prewarning and alarm. If the insulation resistance 
exceeds the release value (response value plus hysteresis), the alarm relays return to their 
initial position. Insulation faults are distinguished according to AC and DC faults (indica-
tion ±). If the fault memory is enabled, the alarm relays remain in the alarm state until the 
reset button is pressed or until the supply voltage is switched off. The device function 
can be tested using the test button. The parameterisation of the device can be carried 
out via the LC display or the function keys integrated in the front plate.

The connections to the system (L1 / L2) and to earth (E / KE) are either automatically checked 
every 24 h, or by pressing the test button or when supply voltage has been connected. In 
case of interruption of a connecting lead, the alarm relay K2 switch, the LEDs ON // AL1 // 
AL2 flash and the following message appears on the display:

"E.02" signals a fault in the connecting leads to the system,

"E.01" signals a fault in the connecting leads to PE. 

After eliminating the fault, the alarm relays return to their initial position either automatically 
or by pressing the reset button.

After connecting the device for the first time, the nominal system voltage is measured 
and the response values are set automatically.

The A-ISOMETER® IR425 uses the AMP measuring principle.

The IR425 series complies with the requirements of the device standards: IEC 61557-8, 
IEC 61557-9, ASTM F1669M-96 (2007).