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Power Factor Correction Unit Replacement at a Large UK Grain Processing Plan

Maintaining efficient electrical systems is critical in high-demand industrial environments, especially in sectors like grain processing where large motors and continuous operations place significant load on power infrastructure. Recently, we completed a full replacement of a power factor correction (PFC) unit at a major UK grain processing plant, upgrading both reliability and performance in a single-day installation.

The Challenge

The existing PFC unit had reached the end of its service life. It had become unreliable and was based on outdated technology, resulting in reduced efficiency and increased risk of failure. The site was operating at a lagging power factor of approximately 0.89, leading to unnecessary reactive power demand and potential financial penalties from the utility supplier.

Given the plant’s operational demands, maintaining power quality and improving efficiency were essential priorities.

The objective was clear:

  • Replace the failed unit quickly to minimise disruption
  • Upgrade to modern, more reliable components
  • Improve overall system performance and safety

The Solution

We installed a new custom built power factor correction unit in the same location as the original, utilising the existing cabling infrastructure. This approach significantly reduced installation time and complexity while keeping costs under control.

Key Upgrades Included:

  • 480V Rated Capacitors
    The new capacitors provide improved durability and performance, better suited to modern industrial electrical systems and fluctuations in load.
  • Soft Switching Contactors
    These reduce electrical stress during switching operations, extending the lifespan of components and improving overall system reliability.
  • Lovato DCRL5 Power Factor Controller
    A modern controller offering precise regulation, improved monitoring, and enhanced control over the correction process to maintain optimal efficiency.
  • Additional Fire Trace Protection
    At the client’s request, we integrated a fire trace protection system within the unit. This adds an important layer of safety, helping to protect internal components and mitigate fire risk—particularly important in environments where dust and combustible materials may be present.

Installation & Commissioning

The entire project was completed efficiently by a two-engineer team in just one day. Careful planning and the reuse of existing infrastructure allowed for a streamlined installation process with minimal disruption to site operations.

Once installed, the system was fully commissioned, tested, and brought online. The results were immediate and measurable, with the site’s power factor improving from 0.89 lagging to unity (1.0). This correction significantly reduced reactive power draw and optimised the overall electrical efficiency of the plant.

Environmental Responsibility

All old equipment was removed from site and disposed of responsibly in line with current environmental regulations, ensuring full compliance while minimising environmental impact.

The Outcome

The plant now benefits from:

  • Power factor improvement from 0.89 to unity, reducing reactive power charges
  • Improved electrical efficiency across the installation
  • Increased reliability and reduced maintenance requirements
  • Enhanced safety due to upgraded protection systems

Conclusion

Upgrading aging power factor correction equipment is a smart investment for any industrial facility. Not only does it improve efficiency and reduce operational costs, but it also ensures compliance with modern standards and enhances overall site safety.

This project demonstrates how, with the right approach and expertise, even critical electrical upgrades can be completed quickly, safely, and with minimal disruption—while delivering immediate, measurable performance improvements.

 

 

 

 

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PFC Upgrade at Magistrates Court

Power Factor Correction Upgrade at Magistrates Court – South of England

At PFC Engineering, we’re often called in to assess and resolve issues where existing power factor correction (PFC) systems are no longer suitable for the demands of a site. This was recently the case during a scheduled maintenance inspection at a magistrates court in the south of England.

Initial Findings

During our inspection, it quickly became clear that the existing PFC system was not fit for purpose. The installation consisted of a fixed 50kVAr unit, which was insufficiently flexible for the site’s varying load profile.

In addition to this, a more serious issue was identified upstream — the PFC unit was being supplied via a fuse switch that had begun to fail, with visible signs of overheating and burning on the L3 phase. This posed a significant reliability and safety risk, requiring urgent attention.

Load Survey & System Assessment

As part of our standard process, we carried out a load survey while on site to better understand the electrical characteristics of the installation. The results showed that:

  • The overall kVAr demand of the site was adequate
  • However, the existing correction stage was too large and inflexible
  • The fixed nature of the system meant it could not adapt to changing load conditions

This was particularly problematic during periods of low demand, such as overnight and weekends. With the capacitor permanently in circuit, the site was being pushed into a leading power factor, which can be just as undesirable as a lagging one—potentially leading to voltage instability and increased stress on electrical equipment.

Proposed Solution

To resolve both the safety issue and improve overall performance, we recommended a full upgrade of the PFC system.

Key elements of the solution included:

  • Removal of the failing fuse switch
  • Installation of a new FS100 automatic PFC unit
  • Integrated 100A MCCB for safe and reliable local isolation
  • Introduction of smaller capacitor stages to allow finer, more accurate correction

To future-proof the installation, the new unit was also specified with detuning reactors. These are essential in modern electrical environments where harmonic distortion is increasingly common, helping to protect capacitors and prevent resonance issues.

Installation & Commissioning

The work was carried out efficiently by a single PFC Engineering engineer, scheduled out of hours to minimise disruption to court operations.

The scope of works included:

  • Safe isolation and removal of the failed fuse switch and existing PFC equipment
  • Responsible disposal of all redundant components
  • Installation of the new FS100 PFC unit in the existing location
  • Installation of a new current transformer (CT) circuit for accurate system monitoring
  • Full testing and commissioning of the new system

The Result

The upgraded system now provides:

  • Accurate, stage-controlled power factor correction
  • Improved energy efficiency and reduced risk of penalties
  • Elimination of leading power factor during low-load periods
  • Enhanced safety with modern protection and isolation
  • Increased resilience against harmonic distortion

If your site is running an older or fixed PFC system, it may no longer be suitable for today’s dynamic electrical loads. PFC Engineering can carry out detailed inspections, load surveys, and upgrades to ensure your system is safe, compliant, and operating at peak efficiency.

Get in touch today to discuss your PFC requirements.

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Power Factor Replacement in Central London

Central London Offices – PFC System Replacement

At PFC Engineering, we recently completed a comprehensive power factor correction (PFC) upgrade for a large office building in central London, replacing ageing components with a modern, high-performance solution.

Project Overview

The existing PFC system had reached the end of its service life, with original capacitors and 210Hz detuned reactors no longer providing reliable performance. To restore efficiency and ensure long-term stability, a full strip-out and rebuild was carried out. Prior to the repairs a load analysis determined that only half of the capacitors in each unit would be required to reach a healthy power factor of >0.95 inductive

Our Solution

Our engineers removed all the original capacitor banks and 210hZ reactors and installed a new system using high-quality components from Frako, including:

  • Frako 50kVar AM tray capacitor assemblies (480V rated)
  • 189Hz detuned reactors

This upgrade improves harmonic filtering, reduces system stress, and enhances overall power quality across the installation.

Delivery

The project was completed by a two-engineer team over a two-day period. Careful planning and on-site coordination ensured the works were delivered efficiently with minimal disruption to the building’s daily operations.

The Result

The upgraded PFC system now provides:

  • Improved power factor and energy efficiency
  • Increased reliability and lifespan of electrical infrastructure
  • A future-proofed solution aligned with modern load demands

 

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Electrical Riser Metering with Remote Monitoring

We were commissioned to design and deliver a remote monitoring solution within a high-rise office building in central London. The brief was to provide accurate monitoring of standard load and power consumption across multiple power and lighting distribution boards located on several floors of the building, while ensuring minimal disruption to day-to-day operations.

The proposed solution involved the installation of quad load and energy consumption meters, each housed within a standalone consumer unit. Split-core current transformers (C.Ts) were fitted to allow each individual distribution board to be monitored without the need for power interruption. All meters were daisy-chained together and connected to a dedicated Gateway, enabling secure remote access to live and historical data via a cloud-based platform. This element of the system was delivered in collaboration with our partners at GO-Monitor, providing the client with reliable remote visibility and ongoing performance insights.

In addition to the distribution board monitoring, we supplied and installed an Acuvim Type A Class Power Quality Analyser within the main LV switchboard. This device was configured to monitor overall power quality, capturing key parameters such as voltage, current, harmonics, and power factor. The analyser was supported by its own dedicated Gateway to ensure uninterrupted data transmission and independent remote access.

All installation works were carried out by two engineers over the course of one week. The project was completed efficiently and safely, with no interruption to the building’s electrical supply or disruption to site operations.

       

 

 

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Surge Protection Replacement at Office Building

During the annual Power Factor Correction (PFC) service, an inspection of the on-site Surge Protection Device (SPD) identified reduced protection levels on two of the three phases. This degradation is most likely attributable to a recent voltage transient on the incoming electrical supply, which has partially exhausted the internal protection components of the device. As a result, the SPD was deemed no longer capable of providing the required level of protection and was recommended for replacement to maintain system integrity and compliance.

The existing Surge Protection Device was DIN-rail mounted within the mains Low Voltage (LV) panel and supplied via a 100A moulded case circuit breaker (MCCB), allowing for straightforward and safe replacement. A return visit to site was arranged, during which our engineer installed a direct replacement unit. The new SPD was fitted using the existing mounting arrangement and power cabling, minimising disruption and ensuring continuity of protection.

The installed Type 1/2 Surge Protection Device is designed to provide combined protection against high-energy surge events, such as lightning-induced transients, as well as lower-level over-voltage conditions arising from operational events like load switching. Once installed, the device restored full surge protection across all three phases, safeguarding downstream equipment and improving the overall resilience of the site’s electrical installation.

 

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Merry Christmas 2025

Wishing all of our customers a Merry Christmas and Happy New Year

We look forward to working with you again in 2026!

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Active Harmonic Filter Installation – Alloa, Scotland

Initial Site Condition

The existing Power Factor Correction (PFC) system at the site was rated at 300 kVAr, configured in three stepped stages. On inspection, the following conditions were recorded:

  • Step 1: Operating at ~55% capacity, with 2 x 200 A fuses blown.
  • Step 2: Operating at ~30% capacity, with 3 x 200 A fuses blown.
  • Step 3: Operating at ~10% capacity and still functional.

With only 90 kVAr of reactive compensation available, system monitoring showed that the Total Harmonic Distortion Voltage (THDV) increased from 3.0% to 4.5%, indicating a significant interaction between the compromised PFC and site harmonics.

Key Observations

  • The existing PFC unit was found to be at end-of-life and required a complete rebuild.
  • Given the requirement for detuned reactors, there was insufficient space within the existing LV mains panel, meaning a new freestanding detuned PFC system would be required for future replacement.
  • Excessive ambient temperatures in the switchroom were identified as a contributing factor. To ensure long-term equipment reliability, it was recommended that air conditioning be installed either for the switchroom environment or directly integrated into any new enclosure.

Power Quality Analysis

A detailed Power Quality Analysis (PQA) was carried out to determine the most effective long-term solution. The analysis confirmed that conventional PFC alone would be insufficient due to the high harmonic content of the site’s electrical load. Instead, the use of an Active Harmonic Filter (AHF) was recommended, either as a standalone solution or in combination with detuned PFC, depending on future reactive power demand.

Proposed & Implemented Solution

Based on the findings, a Comsys P300 Active Harmonic Filter (AHF) was specified, supplied, and installed. The selected model was a 300 A, 480 V P300-300/480 Power Quality Filter, offering advanced harmonic and reactive compensation features.

Application Features

  • Dynamic VAR compensation for improved power factor control.
  • Harmonic elimination, reducing distortion levels across a wide range of orders.
  • Flicker compensation, ensuring stability during fluctuating loads.
  • Load balancing across phases for improved efficiency.
  • Resonance elimination, mitigating potential issues with detuned circuits.

Control Features

  • Customisable harmonic compensation profiles tailored to site requirements.
  • Scalable architecture, allowing multiple P300 units to be paralleled if site load increases.
  • Insensitive to network variations, ensuring stable operation under fluctuating conditions.
  • Idle/standby mode during periods of low load for energy savings.
  • Overload-proof design – cannot be stressed beyond rated limits.
  • Ultra-fast response time (<1 ms) for real-time harmonic correction.
  • ADF Dashboard WUI (Web User Interface) for monitoring and configuration.
  • Multi-SIM enabled GSM gateway for remote diagnostics and reporting.
  • Floating grid frequency support, providing resilience to non-standard network conditions.

Physical Features

  • Standard IP43-rated enclosure (IEC 60529), with higher ratings available if required.
  • Integral door-interlocked load break switch for safety during maintenance.
  • Type 1 and 2 Surge Protective Devices (SPDs) included for transient protection.
  • Correctly rated CT set (xxxx/5) supplied and installed if required.
  • High short-circuit withstand capacity, ensuring resilience in fault conditions.
  • Compact and modular design for simplified installation within the existing switchroom environment.

Outcome

The installation of the Comsys P300 Active Harmonic Filter has significantly improved the site’s electrical performance. Harmonic levels have been reduced to within compliance limits, power factor correction has been dynamically stabilised, and the risk of future equipment failures due to excessive heat or harmonic stress has been mitigated.

This solution provides the site with a scalable, future-proof platform, ensuring stable operation and protecting critical infrastructure from the adverse effects of harmonics, imbalance, and poor power quality.

 

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PFC Replacement – Gym, Newcastle upon Tyne

Initial Findings

During a maintenance visit, the site’s existing power factor correction (PFC) equipment was found to be in a failed state. The following issues were identified:

  • 4 x 125 A DIN fuses had blown, leaving the system unprotected.
  • All 50 kVAr capacitor stages had failed, rendering the PFC system completely inoperative.
  • Given the age and condition of the equipment, an end-of-life replacement of all major components was strongly recommended.

For safety, the defective PFC unit was isolated and left offline, awaiting replacement works.

Replacement Works

A new modular PFC system was designed and installed as a like-for-like replacement for the original ABB equipment. The new trays were engineered to fit directly into the existing framework, allowing:

  • Reuse of existing power leads
  • Retention of original tray fixing points
  • Minimised installation downtime and site disruption

The replacement system incorporates several modern upgrades:

  • Soft-switching contactors – providing smoother capacitor engagement and reduced electrical stress.
  • 480 V rated capacitors – ensuring higher durability and better tolerance to supply variations.
  • Lovato DCRL5 fully digital controller – replacing the outdated relay with an advanced unit offering improved monitoring, automatic step adjustment, and greater accuracy in reactive power management.

Performance Outcome

Following installation, the PFC system successfully restored site efficiency. The gym’s power factor improved from 0.81 inductive to unity (1.00), eliminating excess reactive power demand and significantly reducing the risk of utility penalty charges.

The upgraded PFC not only restores compliance but also delivers:

  • Improved energy efficiency
  • Reduced strain on electrical distribution equipment
  • Extended lifespan of connected plant and machinery
  • A more stable and resilient electrical supply for the site’s daily operations

 

 

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Fire Station – Voltage Optimisation Replacement

A routine maintenance visit identified multiple issues with the existing voltage optimisation (VO) equipment installed at the fire station. The site operates without a standby generator; however, UPS backup is available for essential services, offering limited resilience in the event of extended supply interruptions. Current supply protection was provided via a load breaker (L/B), although for optimal compliance and reliability this should ideally be upgraded to either a fused switch (F/SW) or an MCCB.

Condition of Existing VO Unit

On inspection, the VO system was found to be non-operational. Key issues observed included:

  • The VO remained in inhibit mode, with the key switch failing to restore operation in auto.
  • Contactor banks were not engaging; both C1 and C2 contactors were open, and associated MCBs were found switched off.
  • Phase sequence was confirmed as L1 – L3 – L2, which can contribute to operational anomalies.
  • Residual voltage readings indicated 13 V N–E and 13 V L1–E, traced back as feedback from the fire alarm panel.
  • Solar PV generation was present on site, which can further complicate VO operation and system stability.

Given these conditions, the VO system was left safely in bypass mode as found. Persistent supply-side issues, particularly a voltage rise observed on L2, led to the recommendation for complete replacement of the unit.

Replacement Works

The failed VO system was removed and replaced with a new VM 400 3/5/7/9 Voltage Optimisation unit. The new unit was installed reusing the original terminations and bypass switching system to minimize installation downtime and site disruption.

In line with modern standards, the outdated auto/inhibit control system was fully decommissioned and removed. This ensures greater reliability and reduces unnecessary complexity, while the new VO provides stable, efficient, and fully automated regulation of incoming supply voltage.

Outcome

The installation of the VM 400 VO unit restores effective voltage regulation at the fire station, ensuring equipment protection, extended asset lifespan, and improved energy efficiency. The removal of legacy control circuitry reduces potential points of failure, leaving the site with a simplified, robust, and future-proofed solution.

 

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PFC Upgrade at Community College, Crawley

During a planned maintenance visit to the college’s LV distribution system, engineers discovered a complete failure of the existing power factor correction (PFC) equipment. All six 25 kVAr capacitor units had failed, and four 100 A DIN fuses were found to have blown. This failure left the site operating with no functional PFC, increasing the risk of higher reactive power charges and potential strain on the electrical infrastructure.

A detailed site load test was carried out to establish the actual reactive power requirements under normal operating conditions. The results confirmed that a total of 100 kVAr correction capacity would be more than sufficient to consistently maintain a site power factor above 0.96, comfortably within recommended efficiency standards.

To modernize and simplify the installation, the three failed ABB 25/25 kVAr modules were decommissioned and removed. These were replaced with a single 100 kVAr SBA tray, configured with four independently switched 25 kVAr soft-switching steps. This modular setup ensures greater flexibility, smoother operation, and reduced electrical stress compared to the original equipment.

In addition, the outdated reactive control relay was upgraded to a fully digital Lovato DCRL5 controller. This modern unit provides advanced monitoring, automatic step regulation, and improved accuracy in managing reactive power demand.

The upgrade not only restores reliable PFC capability but also improves system efficiency, reduces electrical losses, and minimizes the likelihood of future reactive energy penalties.

 

     

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Installation of 2 Revcon 200A Active harmonic filters in central London

We were contacted to investigate the increasing harmonic distortion at a large office building in the centre of London, following sites ongoing modernisation plan. After carrying out a week-long Power Quality Analysis, we noticed that while a lot of distortion was coming directly from the grid, site use of Variable speed drives and ongoing LED lighting upgrades were now causing this distortion to exceed the G5/5 design limits.

From this report, we recommend that the existing power factor correction equipment be decommissioned and disconnected. Following this, all of the power factor and harmonic correction requirements of Tx1 & Tx2 main LV supplies could then be provided by a 200Amp Active Power Quality Filter (APQF) connected to each supply and located in the space currently occupied by the power factor correction units. The existing PFC supply MCCB’s and connection cables can then be reused to supply the proposed APQF systems.

 

Installation was carried out over 3 days, including a full commissioning.

 

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100A Harmonic Filter Install at Magistrates Court

During a planned upgrade of this site’s main LV Panel, it was recommended that some Filtering equipment be installed to help reduce the site background Harmonics.

We were then approached to find a solution, and upon review of all the site’s load details as well as the planned upgrade works, we recommend installing a wall-mounted 100A, 4-wire Active Power Quality Filter.

As the new LV panel was still being built, additional specifications were added to allow for an easier connection of the AHF, including a full set of dedicated Filter CTs with shorting links as well as a suitably rated MCCB.

The filter was then mounted and installed during normal working hours, along with a full commissioning by our site engineer.

 

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