Why Power Factor Correction Matters in Industrial Power Systems

The power factor (PF) of an AC power system is a measure of how effectively power from the mains is used. It's the ratio of real power (in watts) absorbed by the load to apparent power (in volt-amperes) flowing through the circuit. Real power, calculated as the average value of the instantaneous product of voltage and current, represents the actual electrical energy available to perform work. In contrast, apparent power is calculated as the product of the root mean square (RMS) values of voltage and current. When energy is temporarily stored in the load and returned to the source, or when a non-linear load distorts the current waveform, apparent power exceeds real power. This causes more current to flow through the circuit than needed for transferring usable power.

A perfect power factor is 1, meaning voltage and current are in phase and that all of the power is doing useful work. A PF less than 1 means voltage and current are out of phase, reducing effective power transfer. In AC circuits, capacitive or inductive reactance causes phase shifts. For capacitive loads, current leads voltage; for inductive loads, current lags. Use the mnemonic CIVIL: [Capacitive (C), I leads [comes before] V; Inductive (L), I lags [comes after] V].

In industrial settings, inductive loads dominate. Most industrial equipment—such as motors, transformers, welding machines, and induction heaters—relies on magnetic fields to operate, making it inductive. As a result, these loads cause a lagging power factor.

In an electric power system, a load with a low power factor draws more current than a high PF load to deliver the same useful power. This leads to greater energy losses, higher stress on distribution infrastructure, and the need for larger, more expensive components. Furthermore, a low power factor can cause unnecessary strain on the electrical equipment itself, potentially leading to premature failure.

For example, a 300W power supply unit (PSU) with a 0.6 PF draws 500VA from the grid—equating to infrastructure stress for 500W just to deliver 300W of usable power. Low PF increases utility costs due to power factor penalties and kVA-based billing. These penalties especially impact industrial and commercial facilities like factories, hospitals, and data centers.

Implementing PFC in an industrial power supply offers several advantages:

• Lower energy costs (avoiding utility penalties for having a low power factor)
• Reduced transmission losses (less wasted energy in cables and transformers)
• Increased system capacity (freeing up power for other loads)
• Improved voltage regulation (more stable power supply)
• Extended equipment lifespan (reduces overheating and stress on electrical components)

We recently introduced our RACPRO1 family of DIN rail power supplies to address the most demanding industrial applications. The RACPRO1-T240, -T480, and -T960 deliver 240, 480, and 960 watts, respectively. These supplies offer multiple PFC advantages, making them the ideal choice for industrial automation and mission-critical applications. Some of these PFC advantages are as follows:

High Power Factor for Maximum Efficiency

• The RACPRO1 series features active PFC, ensuring a high power factor (typically >0.9)
• This minimizes wasted energy and optimizes power usage, reducing unnecessary current draw

Lower Energy Costs and Utility Penalties

• A high power factor means less reactive power, reducing transmission losses
• Many utilities impose penalties for a low power factor, so using RACPRO1 power supplies helps avoid extra charges

Reduced Strain on Electrical Infrastructure

• By improving the power factor, RACPRO1 power supplies reduce current demand, allowing for smaller wiring, transformers, and circuit breakers
• This leads to lower installation costs and a more efficient electrical system

Enhanced System Stability and Performance

• With less reactive power circulating in the system, voltage regulation improves, leading to more stable and reliable operation of connected devices
• Helps prevent voltage sags, flicker, and overheating of electrical components

Compliance with Industry Standards

• Meets IEC 61000-3-2 and other international standards for PFC and harmonic reduction, ensuring compatibility in global applications

Supports Mission-Critical Industrial Automation

• The high efficiency and improved power quality make RACPRO1 power supplies ideal for PLC systems, process control, and automated machinery, where consistent performance is essential

Compact and Reliable DIN rail Design

• Despite integrating PFC, RACPRO1 power supplies remain compact, making them easy to install in space-constrained control panels
• Their high MTBF (Mean Time Between Failures) ensures long-term reliability in demanding environments

In addition, active inrush current limitation and PFC >0.9 reduce stress on fuses and circuit breakers. Including state-of-the-art PFC is just one of the ways in which the RACPRO1 series sets a new standard for industrial PSUs.

The RECOM AC/DC, DC/DC, and EMC Book of Knowledge provides an extensive collection of experience and learnings necessary to implement successful AC/DC power supply designs.

Also, RECOM’s Energy Efficiency in AC/DC Power Supplies: Quick Guide to the Essentials blog provides a helpful introduction of ecodesign regulations, which are a set of standards and guidelines established by governments or regulatory bodies to ensure that products are designed to minimize their environmental impact throughout their entire life cycle. These regulations primarily focus on improving energy efficiency and promoting sustainability by reducing waste, emissions, and resource consumption.

The RACPRO1 webpage provides more information about this exciting new DIN-rail mounted power supply family.