Weidmuller CP-DM Series Modules: CP-DM20

Technical Dossier

Product Details And Specifications

Weidmuller CP-DM Series: Comprehensive Module Range and Technical Overview

The Weidmuller CP-DM series represents a standardized family of DIN-rail mounted DC power supply units engineered for continuous-duty industrial environments. These units are deployed across heavy-process industries including petrochemical refineries, offshore platforms, nuclear auxiliary systems, and large-scale chemical processing plants. The CP-DM range converts AC mains input (typically 100–240 V AC, 50/60 Hz) to regulated 24 V DC or 48 V DC output, supplying field instrumentation, PLC I/O racks, solenoid valve banks, and distributed control system (DCS) marshalling cabinets. Their compact DIN-rail form factor and wide input voltage tolerance make them a preferred choice for both greenfield installations and retrofit projects where panel space is constrained. The CP-DM20, the most widely specified model in the series, delivers 20 A at 24 V DC (480 W), and remains the reference unit for this product line.

The Evolution of CP-DM Architecture

The CP-DM series was introduced by Weidmuller as part of its Connectpower platform, targeting the transition from linear regulated supplies to switch-mode power supply (SMPS) technology in industrial control panels. Early variants in the CP-DM family used single-stage power factor correction (PFC) circuits and offered limited output adjustment range (±5%). Subsequent hardware revisions introduced active PFC to comply with EN 61000-3-2 harmonic current limits, extended the output trim range to ±15%, and added DC-OK relay contacts for supervisory integration into SCADA and BMS systems.

The architecture uses a resonant LLC converter topology in higher-wattage models (CP-DM120 and above), reducing switching losses and improving thermal performance in high-ambient-temperature enclosures (up to 60 °C with derating). Lower-wattage models (CP-DM5, CP-DM10) use a simpler flyback topology optimized for cost and compact footprint. All models in the series share a common DIN-rail mounting interface (EN 60715 TH35) and are compatible with Weidmuller's redundancy modules (e.g., CP-RED series) for N+1 parallel operation without external diode ORing circuits.

Compatibility note: CP-DM units produced before 2015 use a legacy DC-OK contact rated at 30 V DC / 0.5 A. Post-2015 revisions upgraded this contact to 60 V DC / 1 A. Integrators replacing older units must verify relay contact ratings against existing supervisory wiring.

CP-DM Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified production and recently discontinued models within the Weidmuller CP-DM series, classified by output voltage and current rating:

24 V DC Output Models

• CP-DM5: 24 V DC / 5 A (120 W) — compact flyback SMPS for low-load instrument loops and signal converters.
• CP-DM10: 24 V DC / 10 A (240 W) — mid-range supply for small PLC I/O racks and distributed field devices.
• CP-DM20: 24 V DC / 20 A (480 W) — primary reference model; standard supply for DCS marshalling cabinets and valve actuator panels.
• CP-DM40: 24 V DC / 40 A (960 W) — high-current output for large I/O assemblies and motor control auxiliary circuits.
• CP-DM70: 24 V DC / 70 A (1680 W) — heavy-duty supply for centralized 24 V DC bus systems in large process plants.
• CP-DM120: 24 V DC / 120 A (2880 W) — LLC resonant topology; used in main distribution panels for continuous-process facilities.
• CP-DM240: 24 V DC / 240 A (5760 W) — high-capacity unit for plant-wide 24 V DC distribution with active PFC and parallel redundancy support.
• CP-DM480: 24 V DC / 480 A (11520 W) — maximum-capacity model in the series; deployed in large refinery and LNG terminal control rooms.
• CP-DM24/5: 24 V DC / 5 A variant with enhanced EMC filtering for sensitive instrumentation environments.
• CP-DM24/10: 24 V DC / 10 A variant with extended temperature rating (-25 °C to +70 °C) for outdoor enclosure applications.
• CP-DM24/20: 24 V DC / 20 A variant with conformal-coated PCB for high-humidity and corrosive-atmosphere installations.

48 V DC Output Models

• CP-DM48/5: 48 V DC / 5 A (240 W) — for telecom-standard 48 V DC systems and HART multiplexer power rails.
• CP-DM48/10: 48 V DC / 10 A (480 W) — mid-range 48 V supply for fiber-optic media converters and remote I/O hubs.
• CP-DM48/20: 48 V DC / 20 A (960 W) — high-current 48 V supply for large telecom-grade DCS communication backplanes.

Accessory / Redundancy

• CP-DM-RED: Redundancy module for parallel operation of two CP-DM units; provides automatic load sharing and failover without external diodes.

Sourcing Hard-to-Find & Obsolete CP-DM Parts

Several models in the CP-DM series — particularly the CP-DM70, CP-DM240, and CP-DM480 — have been placed on limited-availability or end-of-life status by Weidmuller as the manufacturer transitions customers toward the CP-SNT and CP-E series platforms. DriveKNMS maintains a dedicated inventory of new-old-stock (NOS), refurbished, and tested-serviceable CP-DM units to support installed base maintenance without requiring full panel redesigns.

For plants operating under long-term service agreements (LTSA) or subject to regulatory freeze on control system modifications (common in nuclear auxiliary and pharmaceutical manufacturing), direct replacement with the same CP-DM model number is the only compliant option. DriveKNMS provides traceability documentation, including original manufacturer date codes and test records, to satisfy audit requirements under IEC 61511 and ISA-84 functional safety standards.

Cross-reference service: DriveKNMS engineers can identify equivalent replacement units from Weidmuller's current catalog or from third-party manufacturers (Phoenix Contact QUINT, Siemens SITOP) where form-fit-function substitution is acceptable and documented.

Quality Control for the CP-DM Range

Each CP-DM unit processed by DriveKNMS undergoes a structured test protocol before dispatch:

• Input voltage sweep test: Unit is energized across the full rated input range (85–264 V AC) to verify regulation stability and inrush current limiting.
• Output load test: Full-load burn-in at 100% rated current for a minimum of 2 hours; output voltage ripple measured against IEC 61204-3 limits.
• DC-OK contact verification: Relay contact continuity and dropout threshold verified at ±15% of nominal output voltage.
• Thermal imaging: Infrared scan of primary switching components and output capacitor bank at full load to identify latent thermal anomalies.
• Isolation test: Hi-pot test at 1500 V AC between input and output for 60 seconds per IEC 60950-1 / IEC 62368-1.
• Parallel redundancy test (where applicable): Units intended for N+1 operation are tested in parallel with a CP-DM-RED module to verify load sharing balance within ±5%.

All test data is retained for a minimum of 7 years and is available to customers upon request for inclusion in maintenance management systems (CMMS).