What Is a 24V DIN Rail Power Supply and How Does It Power Industrial Control Panels & PLC Systems?

What Is a 24V DIN Rail Power Supply?

A DIN rail power supply is a switched-mode power supply (SMPS) specifically designed to be mounted on a standard 35mm DIN rail (Deutsches Institut für Normung). This standardized mounting system allows panel builders to snap electrical components—such as power supplies, circuit breakers, and relays—directly onto a metal rail inside an enclosure, saving space and drastically reducing wiring time.

The 24V DC output has become the ubiquitous standard for industrial control. Unlike 12V systems which suffer from higher voltage drops over long cable runs, or 48V systems which are typically reserved for telecommunications or heavy motor drives, 24V offers the perfect balance of safety (SELV – Safety Extra Low Voltage) and power delivery for factory automation.

Whether you are looking at a compact TPS030-GP24V (30W) for a small sensor array or a robust TPS100 320W Peak DR Plus for heavy inductive loads, the DIN rail format ensures modularity and rapid replacement during maintenance.

How It Powers Industrial Control Panels & PLC Systems

The primary function of a control panel power supply is to convert incoming AC voltage (typically 115V or 230V) into clean, stable, and isolated 24V DC power. This is critical for the operation of PLC systems.

Stable Voltage for PLCs

A PLC power supply 24V must deliver power with minimal ripple and noise. PLCs contain sensitive microprocessors that execute logic for factory automation. Voltage spikes or dips can cause logic errors, sensor misreadings, or system reboots. High-quality DIN rail power modules feature tight load regulation to ensure the PLC receives exactly 24V, regardless of fluctuations in the AC mains.

Powering Relays and Actuators

Beyond the PLC CPU, the 24V rail also powers I/O modules, contactors, and relays (such as the FINDER 24V/AA relays often used in our industrial cabinets). When inductive loads like solenoid valves or motor contactors actuate, they draw a sudden surge of current. An efficient industrial power supply is designed with high peak power capabilities (often up to 150% or 170% for a few seconds) to handle these inrush currents without triggering overcurrent protection (OCP) and shutting down the system.

The Importance of 95% Efficiency & Active PFC

In modern factory automation, energy costs and thermal management are major concerns for system integrators. This is where a green power supply DIN rail module becomes essential.

Achieving 95% Efficiency DIN Rail

Legacy power supplies often operated at 80-85% efficiency, meaning 15-20% of the consumed power was wasted as heat. A high efficiency 24V supply operating at up to 95% efficiency drastically reduces heat dissipation. Less heat means:

• Longer lifespan for electrolytic capacitors inside the power supply.
• Reduced need for forced-air cooling (fans) inside the control cabinet.
• Lower overall power consumption, contributing to an energy saving DIN rail architecture.

DIN Rail Power PFC (Power Factor Correction)

Industrial environments are heavily regulated regarding power quality. A power factor correction DIN supply utilizes Active PFC circuitry to align the input current waveform with the voltage waveform. This minimizes reactive power and harmonic distortion on the AC mains, ensuring compliance with standards like EN 61000-3-2. Active PFC is crucial for facilities running hundreds of power supplies, as it prevents overloading of the factory’s electrical infrastructure.

Integration into 15U 19″ Industrial Cabinets

A 24V DIN rail power supply does not operate in a vacuum; it is housed within protective enclosures. For heavy-duty applications, system integrators frequently utilize robust housings like the TPS 15U 19 inch Industrial Cabinet.

Engineered for demanding environments, this free-standing 19″ rack provides secure housing for servers, network devices, and DIN rail components. Made from sheet steel with a powder-coated surface (RAL 7035) for corrosion resistance, it ensures a rugged environment that withstands industrial conditions.

Wiring and Component Synergy

Inside these cabinets, the DIN rail power supply works in synergy with other enterprise-standard components. For instance, the 3U chassis version includes:

• ABB S 203M-K32 breakers: Providing AC input protection before the power reaches the DIN rail supply.
• FINDER 24V/AA relays: Powered directly by the 24V DC output for switching high-power loads.
• UK 35 BLUE wiring terminal blocks: Ensuring clean and secure distribution of the 24V DC power to various PLC nodes.

Proper installation is critical for thermal management and EMC compliance. For detailed wiring schematics and spacing requirements, refer to our DIN Rail Power Supply Installation & Wiring Guide.

Selecting the Right DIN Rail Power Module

Choosing the correct factory automation power supply requires analyzing your load profile. TPS ELEKTRONIK offers a wide range of solutions tailored for different tiers of industrial control:

• Low Power / Edge Devices: For remote sensors or small IoT gateways, the TPS010-GP24V offers a compact footprint with low power consumption DIN characteristics.
• Mid-Range Control Panels: The TPS060-GP24V and TPS100-GP24V are the workhorses for standard PLC racks, offering excellent thermal derating curves.
• High-Demand / Pro Series: For advanced automation requiring high reliability, the Pro Series (30-130W) and models like the TPS100-DR1S24A provide enhanced MTBF and robust overvoltage/overcurrent protections.

If your system requires 12V for legacy components, we also provide equivalent high-efficiency models such as the TPS060-GP12V and TPS150-DR1S12A.

RFQ & Procurement Checklist

For procurement teams and electrical engineers preparing an RFQ for a DIN rail industrial control project, ensure you specify the following to get the most accurate technical proposal:

• Total Wattage & Peak Load: Calculate the continuous draw of your PLC and add the peak inrush current of your relays/motors.
• Input Voltage Range: Specify if you need universal AC input (85-264Vac) or specific DC input capabilities.
• Efficiency Requirements: Request high efficiency DIN rail power supply models (>90-95%) if thermal management in your 19″ cabinet is a concern.
• Certifications: Ensure the power supply meets UL, CE, and IEC 62368-1 standards for industrial safety.
• Form Factor: Verify the width of the power supply to ensure it fits the available DIN rail space in your panel.

Ready to source reliable power for your next project? Browse our full catalog of DIN rail power supplies to find the exact match for your specifications.

Frequently Asked Questions (FAQ)

1. Why use 24V DC for PLC systems instead of AC power?
24V DC is classified as Safety Extra Low Voltage (SELV), making it safer for operators. It also provides a stable, noise-free power source essential for the sensitive microprocessors inside PLCs, avoiding the electrical noise inherent in AC lines.

2. What does Active PFC do in a DIN rail power supply?
Active Power Factor Correction (PFC) aligns the input current with the voltage, reducing harmonic distortion and reactive power. This improves overall grid efficiency and is often legally required for industrial equipment over 75W.

3. Can I mount these power supplies in any industrial cabinet?
Yes, as long as the cabinet features a standard 35mm DIN rail. For optimal performance, we recommend robust enclosures like our 15U 19-inch Industrial Cabinet, which provides excellent grounding, security, and thermal ventilation.

4. What happens if my control panel draws too much current?
High-quality TPS ELEKTRONIK power supplies feature Overcurrent Protection (OCP). Depending on the model, they will either enter a “hiccup mode” (restarting automatically once the fault is cleared) or provide a temporary power boost to handle short-term overloads without shutting down.