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  • Description
  • Features
  • Applications
  • Ordering Info
  • Downloads
  • Accessories
  • RCM420

    Digital ground fault monitor for grounded and high-resistance grounded AC systems

    The RCM420 monitors for ground fault current in grounded and high-resistance grounded AC systems, both single-phase and three-phase. The RCM420 reads a true RMS value, and displays the read ground fault current in real-time on the built-in digital display. The RCM420 features a steplessly adjustable setpoint from 10 mA to 10 A. Along with the main alarm value, a prewarning alarm, set as a percentage of the main alarm value, may be set.

    All settings for the device are changed via the device's onboard, easy-to-use menu. Three separate time delays may be utilized - a trip delay (0 to 10 s), a startup delay (0 to 10 s), and a delay on release (0 to 99 s). Two SPDT alarm relays may be set to normally energized or normally de-energized operation, and may be set to latching or non-latching operation. An external BENDER current transformer is required for operation.

  • Key Features: RCM420

    • Ground fault monitoring for grounded and high-resistance grounded AC systems
    • True RMS reading
    • Digital display showing ground fault current in real-time
    • Adjustable response value from 10 mA to 10 A
    • Many different current transformer sizes available
    • Built-in test and reset button
    • Connections for external test and reset
    • Optional versions with analog outputs
    • Adjustable time delays for response delay, startup delay, and delay on release
    • Latching or non-latching operation, selectable
    • 2 SPDT Form-C contact outputs, normally energized or de-energized operation, selectable
  • Applications: RCM420

    • Ground fault detection in grounded and high-resistance AC systems
    • Branch monitoring
    • Motors and motor control systems
    • Generators, portable and fixed
    • Alarm systems, safety devices
    • General industrial systems
    • Controls and control systems
    • Heat tracing systems
    • Marinas
  • Ordering information: RCM420

    NameResponse ValueSPDT contact outputSupply VoltageOrdering Number
    RCM420-D-110 - 10000 mA 2AC 16 - 72 V (42 - 460 Hz) DC 9.6 - 94 V B94014001
    RCM420-D-210 - 10000 mA 2AC 70 - 300 V (42 - 460 Hz) DC 70 - 300 V B94014002
  • Downloads: RCM420

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    RCM420
    English 08.2013
    Download
    Installation Bulletin
    RCM420
    English 08.2013
    Download
    Menu Overview / Settings Checklist
    RCM420
    English 08.2013
    Download
    User Manual
    RCM420
    English 03.2012
    Download
    Installation Bulletin
    RCM420-DM
    English 10.2012
    Download
    User Manual
    RCM420-DM
    English 07.2010
    Download
    Brochure
    Overview of Products
    English 06.2017
    Download
    3D STEP Drawing
    420 Series (Standard)
    N/A 06.2013
    Download
  • Accessories: RCM420

    AC Current Transformers

    Current transformers for RCM and RCMS series ground fault monitors (AC only systems)

    NameOrdering Number
    W0-S20B911787
    W1-S35B911731
    W2-S70B911732
    W3-S105B911733
    W4-S140B911734
    W5-S210B911735
    Rectangular AC Current Transformers

    Rectangular current transformers for RCM and RCMS series ground fault monitors (AC only systems)

    NameOrdering Number
    WR70x175SB911738
    WR115x305SB911739
    WR115x350SB911740
    WR200x500SB911763
    WR70x175SPB911790
    WR115x305SPB911791
    WR115x350SPB911792
    WR200x500SPB911793
    Split-Core AC Current Transformers

    Split-core current transformers for RCM and RCMS series ground fault monitors (AC only systems)

    NameOrdering Number
    WS20x30B98080601
    WS50x80B98080603
    WS80x120B98080606