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  • AC/DC sensitive measured value acquisition type B
  • Adjustable response values
  • For protection of persons, fire protection, plant protection

The AC/DC sensitive residual current monitor RCMA423 is designed for monitoring earthed power supply systems (TN and TT systems) where smooth DC fault currents or residual currents continuously greater than zero may occur. These are in particular loads containing six-pulse rectifiers or one way rectifiers with smoothing, such as converters, battery chargers, cons­truction site equipment with frequency-controlled drives. Currents in single conductors can also be monitored by RCMA423.

The prewarning stage (50…100 % of the set response value IΔn2) allow to distinguish between prewarning and alarm. Since the values are measured with measuring current transformers, the device is nearly independent of the load current and the nominal voltage of the system.

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  • Applications
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  • Ordering information
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  • AC/DC sensitive residual current monitor Type B acc. to IEC 62020 and IEC/TR 60755
  • r.m.s. value measurement (AC+DC)
  • Two separately adjustable response values 30 mA…3 A
  • Frequency range 0…2000 Hz
  • Start-up delay, response delay and delay on release
  • Digital measured value display via LC display
  • Measured value memory for operating value
  • CT connection monitoring
  • 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 and fault memory behaviour selectable
  • Continuous self monitoring
  • Multi-functional LC display
  • Password protection for device settings
  • Sealable transparent cover
  • Push-wire terminal (two terminals per connection)
  • Two-module enclosure (36 mm)
  • AC/DC sensitive residual current monitoring in earthed two, three or four conductor systems (TN and TT systems)
  • Monitoring of variable-speed drives, UPS systems, construction site equipment, printing machines, battery systems, laboratory equipment, wood working machines, MF welding systems, furniture industry, medical electrical equipment, etc.
  • AC/DC sensitive current monitoring of single conductors de-energised under normal conditions (e.g. N and PE conductors)


Optional accessories for LINETRAXX® RCMA423

Measuring current transformers
TypeInternal diameter (mm)Art. No.
CTUB101-CTBC20ø 20B78120010
CTUB101-CTBC20P ø 20B78120020
CTUB101-CTBC35 ø 35B78120012
CTUB101-CTBC35P ø 35B78120022
CTUB101-CTBC60 ø 60B78120014
CTUB101-CTBC60P ø 60B78120024
CTUB101-CTBC120 ø 120B78120016
CTUB101-CTBC120P ø 120B78120026
CTUB101-CTBC210 ø 210B78120018
CTUB101-CTBC210P ø 210B78120028

Connection cable measuring current transformer – RCMA423-D
TypeLength/mArt. No.

TypeArt. No.
Mounting clip for XM420 enclosureB98060008

Variants of LINETRAXX® RCMA423

TypeResponse range IΔnFrequency rangeSupply voltage US*Art. No.**
RCMA423-D-130 mA…3 A0…2000 HzDC 9,6…94 V /
AC 16…72 V, 42…460 Hz
RCMA423-D-230 mA…3 A0…2000 HzDC 70…300 V /
AC 70…300 V, 42…460 Hz
* Absolute values
**(B7… = push-wire terminal / B9… = screw-type terminal)

Downloads for LINETRAXX® RCMA423



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