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  • Ground-fault monitor for grounded and high-resistance grounded AC/DC systems
  • Modular installation using a single external current transformer
  • Works with AC/DC power conversion equipment including variable frequency drives
  • Digital display with real-time readings
  • Configurable Form-C (SPDT) relay contacts

The RCMA423 monitors for ground-fault current in solidly-grounded and high-resistance-grounded AC/DC (single-phase or three-phase) systems. The RCMA423 is also compatible with systems that contain power conversion equipment, such as variable frequency drives and inverters.

The pickup value is adjustable from 30 mA to 3 A (for a lower pickup value, refer to RCMA420 series). A separately configurable pre-warning alarm is also available. Three separately adjustable time delays are included - a pickup delay, startup delay, and delay on reset.

The RCMA423 provides an accurate, RMS value. Measurements are displayed in real-time via the device's on-board digital display. All device are configured using the display and push buttons. Two Form-C (SPDT) relay outputs are separately configurable to trigger on pre-warning or main alarms.

A single current transformer connects to the RCMA423 for measuring ground-fault current. A wide range of sizes are available.


  • Ground-fault monitoring for solidly-grounded and high-resistance-grounded AC/DC systems
  • Meets or exceeds code requirements for ground-fault detection on grounded AC/DC systems, where applicable
  • Works on systems with power conversion equipment, including variable frequency drives and inverters
  • RMS measurement values
  • Digital display showing measured ground-fault current in real-time
  • Adjustable pickup value from 30 mA to 3 A
  • Connects to a single current transformer, available in a wide range of sizes
  • On-board test and reset buttons with connections for external activation
  • Adjustable time delays (pickup, startup, on reset)
  • Latching or non-latching operation
  • Two Form-C (SPDT) alarm outputs, operating normally energized (failsafe) or de-energized (non-failsafe)


  • Ground-fault monitoring on grounded and high-resistance grounded AC/DC systems
  • General power distribution
  • Motors and motor control centers
  • Generators, portable and fixed
  • Control systems
  • Heat trace systems, per NEC 427.22 and CEC 62-116
  • Battery backup systems
  • Grounded solar arrays, per NEC 690.41(B) (2017 edition), NEC 690.5 (2014 edition), and CEC 64-064(4)
  • Energy storage systems

Downloads for LINETRAXX® RCMA423

CE Declarations of Conformity RCMA42x 88.7 KB 2022/08/12 06:17:2512.08.2022 06:17:25
Manuals RCMA423 1.7 MB EN2021/05/07 10:08:2707.05.2021 10:08:27D00063
Datasheets RCMA423 332.7 KB EN2020/01/10 10:35:0310.01.2020 10:35:03D00063
Quickstarts RCMA423 1,019.8 KB EN2021/05/07 10:09:0807.05.2021 10:09:08D00063
Datasheets XM420 interface options 223.5 KB EN2019/05/13 10:31:3613.05.2019 10:31:36D00051
Technical Information Changed variants of relays from goldplated to silver-plated contacts 166.3 KB EN2022/06/27 09:03:0827.06.2022 09:03:08

Optional Accessories for LINETRAXX® RCMA423

Connection cable for use with RCMA420/423 and CTUB100 series current transformers

Part No.LengthOrdering No.
CTX-1003' (1m)B98110080
CTX-2508' (2.5m)B98110081
CTX-50016' (5m)B98110082
CTX-100032' (10m)B98110083

Enclosure mountings

Part No.Ordering No.

AC/DC current transformers

Part No.OpeningShape and TypeOrdering No.
CTUB101-CTBC200.78" (20mm)circular, solidB78120010
CTUB101-CTBC20P0.78" (20mm)circular, solidB78120020
CTUB101-CTBC351.35" (35mm)circular, solidB78120012
CTUB101-CTBC35P1.35" (35mm)circular, solidB78120022
CTUB101-CTBC602.4" (60mm)circular, solidB78120014
CTUB101-CTBC60P2.4" (60mm)circular, solidB78120024
CTUB101-CTBC1204.7" (120mm)circular, solidB78120016
CTUB101-CTBC120P4.7" (120mm)circular, solidB78120026
CTUB101-CTBC2108.25" (210mm)circular, solidB78120018
CTUB101-CTBC210P8.25" (210mm)circular, solidB78120028


Part No.Supply VoltageOrdering No.
RCMA423-D-116-72 VAC (42-460 Hz), 9.6-94 VDCB94043023
RCMA423-D-270-300 VAC (42-460 Hz), 70-300 VDCB94043025