• Insulation monitoring device for AC IT systems
  • Application main circuits
  • According to IEC 61557-8
  • Two separately configurable response values
  • Multi-functional LC display

The ISOMETER® of the IR470LY series is designed to monitor the insulation resistance of unearthed AC and three-phase systems (IT systems) AC/3(N)AC 0…793 V. In combination with a coupling device, the Isometers can also be used for higher voltages. An external supply voltage allows de-energized systems to be monitored too.

The systems to be monitored should not contain DC components. Due to the measuring principle, insulation faults downstream of directly connected rectifiers are indicated with increased response sensitivity. The set response values apply to the pure AC system only.

The product has been discontinued

Do you already know our new product generation:

  • Features
  • Applications
  • Accessories
  • Ordering information
  • Downloads
  • Insulation monitoring for AC, 3(N)AC systems 0…793 V (IT systems)
  • Nominal voltage extendable via coupling device
  • Response values, adjustable 1…200 kΩ
  • Connection monitoring system/earth
  • Power ON LED, Alarm LED for signalling AC, L+, L- insulation faults
  • LED bar graph indicator for signalling AC, L+, L- insulation faults
  • Connection for external kΩ indication
  • Combined test and reset button
  • Connection external test/reset button
  • Alarm relay with two potential-free changeover contacts
  • Selectable N/O or N/C operation
  • Fault memory behaviour, selectable
  • AC, 3(N)AC main circuits (without directly connected rectifiers), such as motors, pumps, rolling mills without variable-speed drives, air cooling and air conditioning systems, lighting systems, heating systems, mobile generators, building services, domestic electrical installation practice, etc.


Optional accessories for ISOMETER® IR470LY

External kΩ measuring instruments
TypeArt. No.

Coupling devices
TypeNominal system voltage UnArt. No.
AGH204S-4AC 0…1650 VB914013
AGH520SAC 0…7200 VB913033

Variants of ISOMETER® IR470LY

TypeSupply voltage USArt. No.
IR470LY-40AC 230 VB91048007
IR470LY-4011AC 24 VB91048012
IR470LY-4012AC 42 VB91048002
IR470LY-4013AC 90…132 V*B91048011
IR470LY-4015AC 400 VB91048008
IR470LY-4016AC 500 VB91048018
IR470LY-4017AC 690 VB91048017
IR470LY-4018AC 440 VB91048024
IR470LY-4021DC 9,6…84 V*B91048006
IR470LY-4023 DC 77…286 V*B91048026
Other supply voltages on request
* Absolute values

Downloads for ISOMETER® IR470LY



Category Product Language Date Size Download