Schneider BMXCPS3020 Power Supply

The Schneider BMXCPS3020 delivers stable 24 VDC power for Modicon M340 PLC systems. This module mounts directly on the main rack next to the CPU. You will find it in industrial control cabinets across many manufacturing sectors. It provides 20 watts of continuous output for backplane and I/O modules. Therefore, this unit ensures reliable operation of your entire control system.

This module measures 105 mm in height and 38 mm in width. Its depth reaches 85 mm for standard rack mounting. The unit weighs approximately 0.42 kilograms. It contains one main switching transformer and seven electrolytic capacitors. Four status LEDs indicate power and diagnostic conditions. Additionally, you get a removable terminal block for easy wiring.

Key Technical Specifications

Parameter	Value
Manufacturer	Schneider Electric
Model	BMXCPS3020
Product Type	Power Supply Module
Input Voltage	100-240 VAC (50/60 Hz)
Input Current	0.5 A maximum
Output Voltage	24 VDC
Output Power	20 W
Output Current	0.83 A
Efficiency	87% typical
Hold-up Time	15 ms at full load
Height	105 mm
Width	38 mm
Depth	85 mm
Weight	0.42 kg
Transformer Count	1 (main)
Capacitors	7 (electrolytic)
Energy Storage	≈ 950 µF
Status LEDs	4 (PWR, OK, OVLD, BOOST)
Protection	Overvoltage, short circuit, thermal
Operating Temperature	0°C to +60°C

Internal Architecture and Energy Storage

The Schneider BMXCPS3020 stores moderate energy in its capacitor bank. Seven electrolytic capacitors hold approximately 950 microfarads of total capacitance. This storage allows the supply to ride through 15 ms AC line drops. A switching regulator operates at 75 kHz for high efficiency. The main transformer provides 1500 VAC isolation between input and output. An optocoupler feeds back output voltage for tight regulation. The module includes automatic overload shutdown with auto-recovery. A green OK LED confirms normal output voltage status.

Connection Interfaces and Wiring Details

You will find a 3-terminal AC input block on the bottom face. Connect the live wire to the L terminal and neutral to N. Connect the protective earth wire to the PE terminal. Use 14 AWG copper wire for all AC power connections. The Schneider BMXCPS3020 supplies 24 VDC directly to the M340 backplane. Two additional terminals provide auxiliary 24 VDC for field devices. Four LEDs show input power, output OK, overload, and boost status. A red OVLD LED lights up during overload or short circuit conditions. The power supply automatically recovers after removing the fault.

Installation and Mounting Steps

You slide this power supply into the leftmost slot of the M340 rack. First, align the module with the backplane guides carefully. Then, push it firmly until the connector seats completely. Secure the front panel with the integrated locking screw. Connect the AC input wires to the proper terminals. The Schneider BMXCPS3020 automatically detects 100-240 VAC input. No voltage selector switch requires manual setting. Leave 40 mm of free space above and below for cooling. The module draws no power from the backplane itself. It supplies all necessary power to adjacent I/O modules. Power on the system and verify the green OK LED before proceeding.