Bender IRDH375 Isometer IRDH375-435 Insulation Monitoring Device

The ISOMETER® of the IRDH375(B) series is designed to monitor the insulation resistance of unearthed main circuits (IT systems) AC, AC/DC 0…793 V resp. DC 0…650 V.

The AMPPlus measurement method meets the particular requirements of modern power supplies which often include rectifiers, converters, thyristor-controlled DC drives and directly connected DC components. In these systems often high leakage capacitances against earth occur due to interference suppression measures. The IRDH375(B) automatically adapts itself to the existing system conditions.

Insulation monitoring for unearthed AC, AC/DC systems 0…793 V, DC 0…650 V

Nominal voltage extendable via coupling device

Two separately adjustable response values 1 kΩ…10 MΩ

Automatic self test, selectable

Connection for external kΩ indication

Test and reset button

Connection external test and reset button

Two separate alarm relays with two potential-free changeover contacts

N/O or N/C operation

Alarm relay for system fault (N/C operation)

Backlit LC display

RS-485 interface

Plug-in terminals

Rated insulation voltage:- AC 800 V

Rated impulse voltage/pollution degree :- 8 kV/3

Nominal system voltage Un :- DC 0…650 V

Supply voltage US (also see nameplate) :- AC 88…264 V

Frequency range US :- 42…460 Hz

Supply voltage US (also see nameplate) :- DC 77…286 V

Power consumption :- ≤ 14 VA

Response value Ran1 :-  1 kΩ…10 MΩ

Relative uncertainty (1…20 kΩ) :- +2 kΩ/+20 %

Relative uncertainty (1…10 MΩ) :-  0.2 MΩ/+20 %

Measuring voltage Um :- ≤ 40 V

Measuring current Im (at RF = 0 Ω  :- ≤ 220 μA

Permissible extraneous DC voltage Ufg :- ≤ DC 1200 V

Permissible system leakage capacitance Ce :- ≤ 500 μF

Cable length :- ≤ 1200 m

Interface/protocol IRDH375B :- RS-485/BMS

Current output IRDH375 (load) :- 400 μA (≤ 12.5 kΩ)

Current output IRDH375B (load) :- 20 mA (≤ 500 Ω)

Operating uncertainty (1…20 kΩ) :-  ±1 kΩ/±15 %

Operating uncertainty (1 MΩ…10 MΩ) :-  ±0.1 MΩ/±15 %

Rated contact voltage  :- AC 250 V/DC 300 V

Making capacity :- AC/DC 5 A

Breaking capacity :-  2 A, AC 230 V, cos phi = 0.4 0.2 A, DC 220 V, L/R = 0.04 s

Ambient temperature (during operation) :-  -10…+55 °C

Ambient temperature (during storage) :-  -40…+70 °C

rigid/flexible :- 0.2…4 mm²/0.2…2.5 mm²

flexible with ferrules without/with plastic sleeve:-  0.25…2.5 mm²

Conductor sizes (AWG) :- 24…12

Ambient temperature, during operation :- -25…+70 °C

Ambient temperature for storage :-  -40…+85 °C

Screw mounting :- 2 x M4

Vibration resistance :- 1.6 mm/10…25 Hz , 4 g/25…150 Hz