Schneider Electric BMXCPS4002 Power Supply Module – Modicon M340

BMXCPS4002 – Backplane Power Architecture of the Modicon M340 Control Platform

The Schneider Electric BMXCPS4002 is a single-slot AC power supply module engineered for the Modicon M340 PLC rack family. It occupies slot 00 of any BMX XBP series rack and delivers regulated DC bus power across three internal voltage rails — 3.3 VDC, 5 VDC, and 24 VDC — to sustain CPU execution, I/O module scanning, and field sensor power simultaneously. With a rated backplane output of 40 W and a universal AC input range of 100–240 VAC at 47–63 Hz, the module operates without manual voltage selection across North American, European, and Asian grid standards, making it a single-SKU solution for globally distributed machine builders and system integrators.

Unlike generic DIN-rail PSUs, the BMXCPS4002 is mechanically and electrically keyed to the M340 backplane connector, ensuring correct slot assignment and preventing installation errors. The module’s internal DC-DC conversion topology maintains output regulation within ±1% under dynamic load transitions — a requirement for deterministic PLC scan cycles where voltage droop on the 5 VDC logic rail would corrupt CPU-to-I/O backplane communication frames.

Real-time Stock & RFQ: [email protected] | WhatsApp: +86 18359268345

Technical Parameters

Hardware Logical Analysis

The BMXCPS4002 employs a flyback-topology switched-mode power supply (SMPS) with active power factor correction (PFC) on the AC input stage. The PFC front-end maintains input power factor above 0.95 across the full 100–240 VAC range, reducing reactive current draw on facility distribution panels — a measurable benefit in high-density control rooms with multiple M340 racks.

EMC Design: The module integrates a two-stage common-mode and differential-mode EMI filter on the AC input, conforming to EN 55011 Class A conducted emission limits. The transformer’s primary-to-secondary creepage distance exceeds 8 mm, satisfying reinforced insulation requirements per IEC 60950-1 and IEC 61131-2. This isolation barrier prevents ground-loop noise from field wiring from coupling into the CPU’s logic supply — a critical design consideration in environments with variable-frequency drives (VFDs) and large motor contactors generating high dV/dt transients on the facility ground plane.

Backplane Bus Architecture: The M340 backplane uses a parallel bus structure where the BMXCPS4002 acts as the sole power source for all modules in the rack. The module’s output capacitor bank is sized to sustain the 40 W load for a minimum hold-up period of 10 ms following AC input loss — sufficient for the M340 CPU (e.g., BMXP342020) to detect the power-fail interrupt, execute the end-of-scan housekeeping routine, and write the application state to battery-backed SRAM before the logic rail collapses. This deterministic shutdown sequence preserves program data integrity across unplanned power interruptions.

Thermal Management: The module uses a passive convection-cooled heatsink integrated into the aluminum housing. Thermal resistance from junction to ambient is characterized at 4.2 °C/W, allowing continuous 40 W operation up to +60 °C ambient without derating. The housing also acts as an EMC shield, providing >40 dB attenuation of radiated emissions from the internal switching frequency (typically 100–200 kHz) to prevent interference with co-located communication modules such as the BMXNOE0100 Ethernet module.

Inrush Current Control: An NTC thermistor in series with the AC input limits cold-start inrush current to below 30 A peak, protecting upstream MCBs from nuisance tripping during rack power-up sequences — particularly relevant in multi-rack systems where several BMXCPS4002 units may be energized simultaneously from a common distribution board.

System Integration Benefits

• Universal AC Input Eliminates Tap Selection: The 100–240 VAC auto-ranging input removes the need for manual voltage tap configuration, reducing commissioning errors in international projects where local grid voltage may differ from the design specification.
• Integrated Sensor Supply Reduces BOM: The onboard 24 VDC / 0.5 A sensor output powers proximity sensors, limit switches, and encoder supply lines directly from the rack, eliminating a separate 24 VDC DIN-rail PSU in small-to-medium I/O configurations and reducing panel wiring complexity.
• Deterministic Hold-Up Enables Controlled CPU Shutdown: The ≥10 ms hold-up time at rated load provides the M340 CPU with a defined window to execute power-fail interrupt service routines, preserving application state and preventing data corruption in battery-backed memory regions.
• Single-Slot Form Factor Maximizes I/O Density: At 30 mm wide (1 slot), the BMXCPS4002 consumes the minimum possible rack real estate, leaving the maximum number of slots available for CPU, communication, and I/O modules in space-constrained enclosures.
• Passive Cooling Eliminates Fan Maintenance: The convection-cooled design has no rotating components, removing fan failure as a maintenance item and supporting MTBF targets in applications where scheduled maintenance intervals are long (e.g., offshore platforms, remote pipeline stations).
• EMI Filtering Protects Co-Located Communication Modules: The two-stage AC input filter and shielded housing prevent conducted and radiated emissions from degrading the signal integrity of Ethernet, Modbus, and Profibus modules installed in adjacent rack slots.
• Mechanical Keying Prevents Mis-Installation: The backplane connector is physically keyed to slot 00, making it impossible to install the power supply in an I/O slot — a hardware interlock that eliminates a class of installation errors during system build and field replacement.
• Short-Circuit Protected Sensor Output Prevents Cascade Faults: The 24 VDC sensor supply includes electronic short-circuit protection with automatic recovery, preventing a field wiring fault from collapsing the sensor supply rail and triggering false input states across the entire I/O module complement.
• Compatibility Across Full M340 Rack Range: A single BMXCPS4002 part number supports all four BMX XBP rack sizes (4, 6, 8, and 12 slots), simplifying spare parts inventory management for maintenance teams operating mixed-size M340 installations.
• IEC 61131-2 Compliance Supports Validated Installations: Formal compliance with the programmable controller hardware standard provides the documentation baseline required for system validation in regulated industries including pharmaceutical manufacturing and food processing.

Quality Assurance & Global Logistics

Every BMXCPS4002 unit dispatched from our Xiamen, China facility undergoes a structured pre-shipment verification process. Each module is visually inspected for enclosure integrity, label authenticity, and connector condition. Output voltage rails are confirmed within specification under a representative load. Batch traceability records are maintained and available on request for quality-audited procurement processes.

Anti-counterfeit screening cross-references Schneider Electric genuine part identifiers including date codes, holographic labels, and housing mold markings. Modules are packed in anti-static ESD bags with foam-lined cartons to withstand international air and sea freight handling. Export documentation including commercial invoice, packing list, and certificate of origin is prepared for all international shipments.

Standard dispatch from Xiamen is within 1–3 business days of order confirmation. Air freight to major industrial hubs — Frankfurt, Houston, Singapore, Dubai — typically transits in 3–5 business days. Sea freight consolidation is available for bulk orders. DDP (Delivered Duty Paid) terms are available for select destinations. All shipments carry a 12-month warranty from the date of dispatch covering manufacturing defects and functional failure under normal operating conditions.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
© 2026 siemensplc.com. All rights reserved.