Residual current monitoring system LINETRAXX® RCMS490-D

continuousdigitalmulti-channel

Product description
The LINETRAXX® RCMS490-D is a multichannel residual current monitor for detection and evaluation of fault, residual and operating currents in earthed power systems. Each device provides 12 measuring channels; multiple devices can be networked via BMS (RS‑485) to monitor large installations. Measurement sensitivity (AC, pulsed or AC/DC) is determined by the selected measuring current transformer (CT).

Key notes / overview

• 12 measuring channels per device for residual current measurement or digital input.
• Device variant RCMS490: one alarm contact per channel; other variants provide global alarm relays.
• Optional AC, pulsed DC or AC/DC sensitive measurement by selecting the appropriate CT for each channel.
• True r.m.s. value measurement; harmonic and DC/THD analysis; adjustable frequency response for personnel, fire and plant protection.

Details
The RCMS family (RCMS460-D/-L, RCMS490-D/-L) supports connection of closed, split-core, rectangular and flexible CT series (examples: CTUB100, CTBS25, CTAC…, WR…, WS…, WF…). CTUB100/CTBS25 series are required for AC/DC sensitive (Type B) measurements and may require a 24 V DC supply. Any combination of CT types can be assigned to the device measuring channels. Up to 90 monitors can be connected on one BMS bus, enabling monitoring of up to 1080 measuring channels.

Features

• Selectable measurement type per channel (AC / pulsed DC / AC‑DC sensitive).
• True r.m.s. measurement and analysis of harmonics, DC component and THD.
• Fast parallel scanning of all channels; preset function and adjustable time delays.
• Response ranges examples: 10 mA…10 A (0…2000 Hz); 6 mA…20 A (42…2000 Hz); 100 mA…125 A (42…2000 Hz) for D4 variants.
• History memory with date/time stamp (300 records) and data logger (300 records per channel).
• Alarm outputs: device versions with two global alarm relays (one changeover each) or RCMS490 with one alarm contact per channel; N/O or N/C operation selectable; external test/reset button input.
• Backlit graphical display (7‑segment style), alarm LEDs, continuous CT connection monitoring and password protection for settings.

Applications

• Monitoring residual, fault and operating currents on switchboards, distribution panels and fixed equipment across wide frequency ranges (0…2000 Hz or 42…2000 Hz depending on CT type).
• Fire-hazard current monitoring and rapid disconnection for fire protection.
• EMC monitoring of TN‑S systems for stray currents and additional N‑PE connections.
• Monitoring of N conductors for harmonic-related overload and of PE/equipotential bonding conductors to ensure absence of current.
• Support for practical test interval determination (e.g., DGUV V3) through logged residual current data.

Variants (summary)

• RCMS490-D-1: Supply DC 16…94 V / AC 16…72 V, 42…460 Hz — model example B94053005.
• RCMS490-D4-1: DC 16…94 V / AC 16…72 V, 42…460 Hz (D4 response ranges) — B94053011.
• RCMS490-D-2: DC 70…276 V / AC 70…276 V, 42…460 Hz — B94053006.
• RCMS490-D4-2: DC 70…276 V / AC 70…276 V, 42…460 Hz (D4) — B94053012.

Pertinent measuring current transformer families (examples)

• CTUB100 / CTBS25 series — closed CTs for AC/DC sensitive (Type B) measurement (0…2000 Hz).
• CTAC…, WR…, WS…, WF… series — closed, rectangular, split-core and flexible CTs for alternating and pulsating currents (Type A, 42…2000 Hz).
• WF… flexible CTs paired with RCC420 signal converter for installations requiring flexible routing.

Accessories and system components (examples)

• 24 V DC power supplies for CTUB100 series (e.g., STEP‑PS range).
• Gateways, repeaters and condition monitors for BMS/Ethernet integration (e.g., COM465IP, CP907‑I, CP915‑I).
• Alarm indicators, test/reset modules, CT connection cables and various CT sizes and formats.

Technical specifications (selection)

• Model: LINETRAXX® RCMS490-D.
• Measuring channels per device: 12.
• Max monitors per BMS bus: up to 90 (→ up to 1080 channels).
• Response ranges examples: 10 mA…10 A (0…2000 Hz); 6 mA…20 A (42…2000 Hz); 100 mA…125 A (42…2000 Hz) for D4 variants.
• Measurement: True r.m.s.; harmonic and DC/THD analysis.
• History memory: 300 records; data logger: 300 records per channel.
• Communication: BMS bus (RS‑485) with BMS protocol; integration via gateways/condition monitors.
• Protection/functions: adjustable frequency response for personnel/fire/plant protection, preset function, adjustable time delays, password protection, continuous CT connection monitoring.