BENDER RCMA420-D-2 Residual Current Monitor

Description

BENDER RCMA420-D-2 Residual Current Monitor

Product Dimensions：

The Bender RCMA420-D-2 is a compact, Type B residual current monitor (RCM) from the LINETRAXX® series. It is designed to evaluate pure DC currents, smooth DC residual currents, and AC residual currents in earthed, grounded system architectures without interrupting power.

Product Detailed Description

The RCMA420-D-2 continuous residual current monitor detects insulation degradation and fault currents at early stages, preventing equipment damage, unexpected downtime, and fire hazards. It operates in conjunction with external measuring current transformers (such as the Bender CTAC, WR, or WS series).

The “-D-2” designation indicates that this model features an integrated LC display with a digital parameterization interface and is powered by a standard AC/DC auxiliary supply range of 70 V to 300 V.

Technical Parameters

Product Advantages

• Comprehensive Type B Monitoring: Capable of measuring smooth DC residual currents in addition to standard AC currents, making it suitable for modern frequency inverter-driven equipment.
• Pre-Alarm & Alarm Functionality: Features two separately adjustable response steps (pre-alarm I_{\Delta n1} and main alarm I_{\Delta n2}), allowing early maintenance warnings before a critical shutdown occurs.
• Non-Disruptive Diagnostics: Continually monitors system insulation health under live power conditions without requiring system isolation or tripping main breakers.
• True RMS Measurement: High-accuracy measurement algorithms ensure precise current readings across harmonic-rich power environments up to 2 kHz.
• Password Protection & Lock: Parametric settings can be locked via password code to prevent unauthorized configuration changes.

Important Considerations & Precautions

• Requires External Current Transformer: The unit cannot measure current directly; it must be paired with an appropriate Bender measuring current transformer (CT) passed through all phase and neutral conductors.
• Do Not Pass Protective Earth (PE): The PE (ground) conductor must never be passed through the measuring current transformer ring.
• Supply Voltage Limits: Ensure the control voltage supply remains within the specified range of AC/DC 70–300 V to avoid damaging internal electronics.
• System Grounding: Designed strictly for grounded (TN/TT) system architectures. (For ungrounded IT systems, insulation monitoring devices such as Bender ISOMETER® series should be used instead).

Product Applications

The RCMA420-D-2 is applied in industrial and commercial environments where smooth DC or high-frequency residual currents may occur:

• Frequency Inverters & Variable Speed Drives (VFDs): Monitoring motor drive outputs and power stages where DC component leakage can blind standard Type A RCDs.
• Data Centers & UPS Systems: Continuous earth-leakage monitoring for sensitive IT facilities without causing nuisance tripping.
• Solar PV & Battery Energy Storage (BESS): Tracking insulation breakdown and earth faults on the AC and non-isolated DC sides.
• Industrial Automation & Process Machinery: Early fault detection in conveyor lines, cranes, and automated assembly plants to ensure continuous uptime.

Shipping Port: Xiamen, China

Payment: Bank of Chicago, Bank of Singapore

Express cooperation: fedex, DHL, UPS and your express account

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