A customer at a large office building in central London recently required a Power Factor Correction unit replacement due to the existing equipment becoming outdated and no longer fit for the sites load.

During our annual maintenance visit we carried out a load survey to determine what the site would require regarding PF correction as well as reviewing the site harmonic distortion levels (THD).

It was found that smaller capacitor stages would help with finer correction as lower loads and that the harmonic levels were above the recommended 3%-4% for operating standard equipment.

As such a new FSi100 was installed. This new unit consists of 3 capacitor stages of 25kVAr, connected  to an IMO MC32 soft switching contactor via a 189Hz detuning reactor.

The unit is then controlled by a 5 stage Lovato DCRL digital control relay.

Our engineer was able to utilise the existing power cable and C.T cable from the previous Power Factor unit and all works were carried out without disruption to site during normal working hours.










A customer at an aerospace manufacturer in the Isle of White wanted an end of life replacement for their existing Power Factor Correction units.

The existing units were 150kVAr each in a Master/Slave set up, meaning that one of the units controlled both. The reason for this set up was because the LV board was split into to two separate supplies and the PFC unit had been installed with a summated C.T circuit.

The like for like replacement of the PFC units meant we were able to re-use the existing power cables, C.T circuits and control cable. All works were completed during normal working hours without any disruption to the site.








Due to a high demand for detuned Power Factor Correction to help reduce harmonics we have added a new product to our FSi range of PFC units.

Introducing the new FSi400 Deep Power Factor Correction unit. This new design fits up to 400kVAr of detuned equipment inside a single cubicle 800mm wide x 650mm deep x 2250mm high.

This means this new design of unit is 400mm less in width compared to our old FSi400 wardrobe style unit allowing for even more versatility when it comes to installation.

Our old style FS400 is still available on request so we are able to build units to your design requirements.

Contact us for more information.


A new customer at a Laundry cleaning factory recently enquired about having their Power Factor Correction unit serviced. The unit was built into the main LV Switchboard and had not been serviced since installation 10+ years ago.

The LV Switchboard is located on the main factory floor and as such over the years the internal components had been covered with a thick layer of lint.

Upon carrying out a full maintenance it was found that all the capacitors had failed along with a number of control fuses. The contactors had very pitted contact faces and were full of lint. And the control relay was outdated and provided very limited information on what the Power Factor unit was achieving.

A load test was carried out while on site as part of the maintenance and it was concluded that the capacitor stages were also too coarse, and site would benefit from smaller stages that would provide finer correction.

Following this visit a full report and quotation was provided to replace all the single-phase capacitors with new high quality, long life metallized polypropylene 480V rated capacitors. Replace all contactors with new Soft Switching contactors and splitting theses stages down into 2 x 25kVAr & 2 x 50kVAr.

The control relay would also be upgraded to a new Lovato DCRL5 digital control relay which would supersede the requirement for the manual key switches.



The unit was stripped down, fully cleaned out and rebuilt with all new components as required, during normal working hours without disruption to site and the unit was left operating satisfactorily.

A  very busy few months at PFC Engineering. Are workshop staff have been working tirelessly to get a multitude of order built and ready for a wide range of customers.

Firstly, 4 of our standard FS200 200kVAr Power Factor Correction units have been made for a switchgear manufacturer in the midlands. Each unit has 4 x 50kVAr capacitor banks and its own built in 400A load break switch for localised isolation. The unit have also been spec’d with a specific type of control relay at the clients request.



Another client in Bridgend has ordered 2 of our newly designed Active Harmonic Filters. Compatible with all three-phase low voltage applications this state-of-the-art unit can be used for harmonic and reactive compensation and well as flicker control, load balancing and has the option for seasonless operation. Lots more information regarding AHF will be coming to the website soon along with what harmonic solution we at PFC Engineering can offer.




And finally for a customer in Cheshire we have 6 custom FSi400 fully detuned power factor correction units in a newly designed FSi400 (Deep) cubicles which provide more flexibility regarding unit location as they don’t take up as much room as the existing FS400 design. Each unit is split into 6 capacitor stages and has its own local isolation of either a load break switch or MCCB depending on install requirements.

Along with these PFC units we have also built 4 300Amp Active Harmonic Filters each with its own load beak switch and custom ventilation. Lots more information about theses AHF will be coming soon but if you want to find out more please feel free to contact us.





Well done to Richard and Aaron for all their hard work and a big thank you to the rest the workshop staff who have helped put all this together.

Along with our partners at GO Monitor, we recently started Phase One of metering installations for a customer at a UK Port. With 14 main supplies to monitor each with its own set of installation challenges two of our engineers spent the week getting each supply connected to its own dedicated mains meter which now can be monitored over a customised IoT web portal by the client.


With the view to expand the monitoring on each LV switchboard, space was allocated to allow for future expansion, in this case to monitor individual supplies as well as the main incomer to allow for accurate KWh readings.


Where available the new metering system was connected using existing voltage and ammeters to make use of the existing C.Ts and Voltage references allowing for installation during normal working hours without interruption to the supply. However, on the few supplies that required more intrusive works, the new metering units were installed awaiting final connections under shutdown conditions.


Below are some examples of the varied installations required around site including metering enclosures close-coupled to existing LV boards, built inside of LV panels and metering enclosures mounted externally.


Click here find out more about remote energy monitoring. 



Today’s shipment of 6 x 300A Active Harmonic Filters and 3 x 360kVAr fully detuned Power Factor Correction unit have been loaded up and is on its way to our customer in Northern Ireland


After a recent company First Aid course the decision was made to buy a new public access AED (automated external defibrillator)

Not only is this excellent piece of kit available to PFC Engineering but also the local community and though we hope it will never be required we are happy that its available to anyone who needs it day or night.

To find out more visit https://www.ipad-aed.com/public-access/


Following a site maintenance at a University in Coventry, two panel built PFC sections were found to have failing components and the original install provided little to no easy maintenance access to the tray assemblies. It was decided that an ‘End of life’ replacement would be carried out on both sections and that we would install 2 x 100kVAr SBA trays of our own design into each of the existing spaces.

All the original capacitor tray we removed along with all the cabling and control wiring. The internal framework was then adjusted along with the addition of vertical struts to attach the new SBA trays to. The copper bar that were located in the rear of the unit would be kept and the new trays connected to using lengths of flexibar.

Once these adjustments were made and the new trays fitted, the control wiring was installed along with a new 5 stage Lovato DCRL digital control relay.

The work was carried out by 1 engineer over the course of a day and a half during normal working hours with all the waste removed from site.

We were asked to carry out a Power Factor Correction service for a condiment manufacturer in Littleborough, near Manchester. Site had two main LV supplies each with its own standalone 200kVAr Power Factor Correction unit. Nether of the unit had been serviced since there original installation in 1995.

A full maintenance inspection was caried out on the units and multiple failures were found including failed capacitor banks, welded contactors, seized fans and outdated controllers. It was also noted that the Surge Protection Device in the main LV Panel on Supply 2 had failed and required replcment.

Each LV supply was looking for around 200kVAr to reach a healthy Power Factor of 0.95 inductive or greater so it was determined that rebuilding the existing units would be the most cost-effective way to get the equipment back up to full operation.

To do this we removed all the original capacitor banks and replaced them with our own 480V Frako CM tray assemblies. We also replaced all the original block contactors with new soft switching contactors to help reduce inrush currents when the capacitor banks are switched into circuit, as well as replacing the failed fans, installing new fan filter elements, and upgrading the digital control relay to a new Lovato DCRL5 controller.

The Surge Protection device was also swapped out for new making sure the supply is protected against voltage spikes.


All the works were completed in 1 day, during normal working hours without any interruption to sites operation.


Following a recent visit to a computer manufacturing site in Warwick, it was found that the existing Power Factor Correction Equipment had a multitude failures. These included, failed capacitors, contactors that had welded closed, and cables that had over heated.


Before Rebuild


The unit itself had never been maintained since its original installation, and now needed repair. It was decided that due to the age of the equipment, and lack of servicing, we would replace the existing trays with our own SBA tray assemblies. This would include all new, long life metallized polypropylene capacitors rated to 480V, new IMO soft switching contactors along with additional sub fusing and new power cables.

The digital control relay was also upgraded to a Lovato DCRL 5, providing more information regarding the PFC as well as advanced functionality over the original one installed on site.

After Rebuild


All work was done in 1 day and site were left fully operating with 400kVAr of new Power Factor Correction Equpitment and an upgraded controller.

Looking for a new challenge? Here at PFC Engineering we are looking to fill roles in both our in house manufacturing as well as our on our site services team.

Please see below for further details and we look forward to hearing from you soon.





Full time positions based near Saffron Walden, Essex.

To assist in the manufacture of Energy Saving Products.

Electrical/mechanical knowledge beneficial but not essential as training provided.

Salary £ Neg (depending on experience).

Please contact PFC Engineering Ltd 01799 530728 or send a C.V to paul.mainey@pfc-engineering.com





 Full time positions required within busy maintenance & installation department providing national coverage.

Good electrical knowledge required preferably with 18th edition update.

Full application training will be provided.

Salary £ Neg. plus vehicle.

Please contact PFC Engineering Ltd 01799 530728 or send a C.V to paul.mainey@pfc-engineering.com