Bender IR420-D4-2 B71016405 Ficha De Dados

32 

TDB101012en / 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

IT control circuits AC 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)

•  

RoHS compliant

•  

Push-wire terminal
(two terminals per connection)

  

  

The A-ISOMETER® IR420 monitors the insulation resistance of unearthed AC control circuits 
(IT systems) 0…300 V. If the systems to be monitored include DC components, such as 
switched-mode power supplies or solenoid valves, the display and operating characteristics 
may be affected. 

The display and response values apply to pure AC systems. 

An external supply voltage allows de-energised systems to be monitored too.

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

automation systems etc.

•   AC control and auxiliary circuits in accordance with IEC 60204-1: "Safety of machinery – 

Electrical equipment of machines, Part 1: General requirements" 

•  Smaller AC IT systems such as lighting systems, mobile generators

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. 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 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" indicating 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® IR420 uses the measurement method "superimposed DC voltage".

The IR420 series complies with the requirements of the device standards: IEC 61557-8, 
ASTM F1207M-96 (2007).