Bender GmbH RCMA420-DM-1 Ground Fault Monitor

The LINETRAXX RCMA420-DM-1 is a two-relay, AC/DC sensitive ground-fault monitor designed for solidly grounded and high-resistance grounded systems, capable of detecting residual current in single-phase or three‑phase installations and in systems with power conversion equipment such as VFDs and inverters. The DM-1 variant provides an adjustable fault pickup of 10–500 mA, a rated measurement range up to 0–2000 Hz, and a versatile power supply configured for DC 9.6–94 V or AC 42–460 Hz (with the 16–72 V option as specified for this family). It uses a single external current transformer and presents real-time RMS fault current on an on‑board LC display, with measurements largely independent of nominal system voltage. Two Form‑C (SPDT) alarm relays are available and can be set for pre-warning or main fault signaling, with options for normally energized (failsafe) or normally de-energized (non-failsafe) operation. On‑board test and reset controls, external activation input, fault memory, and continuous self‑monitoring enhance reliability, while a sealable, RoHS‑compliant 2‑module enclosure (36 mm) and password‑protected settings support field use. Typical applications include general power distribution, motor control centers, generators and energy storage systems, grounded solar arrays, and other environments where precise ground-fault monitoring is critical.