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  • Established 1985over 40 years in the Borders
  • 9 full-time electriciansAll 18th Edition qualified
  • SELECT 17074 · ECA 1683735NSI, MCS, OZEV & RECC
  • £10m / £5m insuredEmployers' & public liability
  • Free fixed-price quotesSupplied free, no obligation

Service overview

What power factor correction does to your bill

Motors, drives, transformers and discharge lighting draw reactive power as well as the real power that does the work. Your supply and your meter carry both. Correction equipment supplies the reactive element locally, so less of it travels down your incomer.

What the service covers

We survey the site, log the load, calculate the correction required, and install and commission capacitor banks, fixed, automatic or detuned where harmonics are present, at the main board or local to the offending loads. Existing correction equipment is also tested, repaired and re-commissioned; a high proportion of the units we inspect have failed stages that nobody has noticed.

Who it is for

Industrial and commercial sites with significant motor load: manufacturing and engineering units, sawmills, cold stores, grain and feed plant, pumping stations, workshops and larger agricultural operations. If your bills show reactive power (kVArh) or an availability charge, correction is worth assessing.

When it is needed

When your invoice carries reactive power or excess capacity charges, when the metered power factor sits below around 0.95, when you need more capacity for new plant but do not want to pay for a supply upgrade, or when an existing capacitor bank is more than a decade old and has never been serviced.

Why professional work matters

Correction is one of the few electrical works with a directly measurable financial return, but only when it is sized against real load data. Oversized or badly specified banks cause their own problems, particularly on sites with variable speed drives generating harmonics. The survey is the part that determines whether the investment pays.

The cost of leaving it

What poor power factor is quietly costing you

Nothing breaks. You simply pay more every month and have less capacity than you think.

  • Reactive charges on every invoice

    Reactive power appears as a separate charge on most commercial and industrial supply contracts. It recurs monthly, indefinitely, and is invisible unless someone reads the invoice line by line.

  • Capacity you cannot use

    Poor power factor consumes part of your agreed supply capacity carrying current that does no work. Sites regularly pay for a supply upgrade when correction would have released the capacity they already had.

  • Higher currents, hotter cables

    Additional current means additional heating in cables, switchgear and transformers, which shortens equipment life and increases losses across the whole installation.

  • Failed banks nobody notices

    Capacitors degrade and contactors fail. An automatic bank with three dead stages looks identical from the outside to a working one, and the charges creep back onto the bill unchallenged.

  • The specification mistake

    Fitting an untuned bank on a site full of variable speed drives can amplify harmonic currents rather than solve a problem. Detuned equipment exists for exactly this reason, and it needs a harmonic assessment to justify it.

Our process

How the job runs, start to finish

  1. 01

    Step 1: Bill review and site inspection

    We look at your supply invoices and metering to identify reactive and capacity charges, and inspect the main board and load types on site.

  2. 02

    Step 2: Load logging and calculation

    Where the load varies, we log it to establish the actual profile and the correction required, and check for harmonic content from drives and electronic loads.

  3. 03

    Step 3: Fixed-price proposal

    You get the recommended equipment, the expected effect on power factor and the released capacity, with a written fixed price. No claim goes in the quote that the data does not support.

  4. 04

    Step 4: Installation and commissioning

    The bank is installed at the appropriate point in the distribution system and commissioned stage by stage, with switching verified under real load and out-of-hours isolation where needed.

  5. 05

    Step 5: Verification and ongoing checks

    Post-installation measurement confirms the corrected power factor, and we can include the bank in a planned maintenance routine so failed stages are found by us rather than by your accountant.

Payment by bank transfer (preferred) or card. Deposits on larger jobs only, agreed case by case before we start.

What you get

The difference it makes on your site

A measurable reduction in charges

Reactive power charges fall in direct proportion to the correction achieved, and the effect is visible on the next invoice rather than in a projection.

Capacity released without a supply upgrade

Correction frequently frees enough headroom to add plant or charging without paying a distribution operator for a larger connection.

Cooler, longer-lived switchgear

Lower current means lower losses and less thermal stress on cables, boards and transformers across the whole installation.

Specified against your data

Sizing follows logged load and harmonic assessment. If the numbers do not justify the investment on your site, we will tell you that.

Installed by your electrical contractor

The firm holding your test results and board schedules installs the equipment, so nothing is fitted against an unverified supply.

Maintained, not forgotten

Optional planned checks confirm every stage is still switching, which is the difference between a one-off saving and a permanent one.

In detail

Equipment, methods and site variations

Correction is not a single product. What suits a sawmill with fixed motor load is wrong for a site running variable speed drives.

Fixed capacitor banks

Suited to sites with a steady, predictable base load: a constantly running motor, a pump set or a compressor. Simple, robust and cost-effective, but only where the load does not vary enough to risk over-correction at light load.

Automatic banks

Switched stages controlled by a relay measuring real-time power factor, bringing capacitance in and out as load changes. This is the usual answer for manufacturing and mixed commercial sites where load varies across a shift.

Detuned banks for harmonic environments

Where variable speed drives, inverters, LED drivers and IT loads generate harmonic currents, detuning reactors are fitted in series with the capacitors to prevent resonance. Sites with significant drive load should assume detuned equipment is required until measurement shows otherwise.

Central versus local correction

Central correction at the main board addresses the charges on your bill. Local correction at a large individual motor also reduces current in the cable feeding it, which helps where a specific circuit is at capacity. The survey establishes which problem you are solving.

Existing equipment: test before you replace

Many sites already have a bank installed years ago and never inspected. We test capacitance stage by stage, check contactors and fuses, verify the controller settings, and often restore performance for a fraction of replacement cost.

Where it applies and where it does not

Correction pays on sites with substantial inductive load and a supply contract that charges for reactive power or capacity. It does not pay on small single-phase premises with domestic-style tariffs, and we will say so rather than sell equipment that will never return its cost.

Accredited for this work

  • SELECT17074
  • ECA1683735
  • NSI Approved (Fire)NSI-000082/FS/S
  • BAFESP203 Registered
  • MCS via NAPITNEP-66400
  • OZEV ApprovedEV chargers
  • RECCRegistered
  • SMAS WorksafeSSIP approved

Before you call

Power Factor Correction: your questions answered

How much does power factor correction cost?

It depends on the correction required in kVAr, whether detuning is needed and where the equipment is installed. We survey and log first, then issue a written fixed price with the expected effect stated in the same document.

How much will I save?

The saving is specific to your load and your supply contract, which is why we log the site rather than quote a headline percentage. The proposal sets out the measured position and the correction we expect to achieve.

How long does installation take?

Most installations are completed within a short, planned isolation window, arranged out of hours where continuity matters. The programme is confirmed with the quote.

Will it interfere with our variable speed drives?

Not when the equipment is correctly specified. Sites with significant drive load are assessed for harmonics and fitted with detuned equipment where required, precisely to avoid resonance problems.

How long does a capacitor bank last?

Capacitors degrade over time and stages can fail silently, so a bank should be inspected periodically rather than assumed to be working. We can include it in a planned maintenance routine.

Can you repair our existing bank?

Usually, yes. We test each stage, check contactors, fuses and controller settings, and restore what can be restored before recommending replacement.

Will correction give us capacity for new plant or EV charging?

Often it will, and that is one of the most valuable outcomes. We assess released capacity as part of the survey, which can avoid the cost and lead time of a supply upgrade.

Is emergency support available if the equipment fails?

Emergency call-outs are available. Out-of-hours calls are answered for existing customers, charged at approximately 1.5 times the standard hourly rate.

Are you accredited to carry out this work?

We are SELECT approved (17074), ECA approved (1683735) and SMAS Worksafe SSIP accredited, with RAMS produced for virtually all jobs and £10m employers' / £5m public liability cover.

Which areas do you cover?

The Scottish Borders and North Northumberland, including Coldstream, Duns, Kelso, Berwick-upon-Tweed, Eyemouth, Chirnside, Greenlaw, Jedburgh and Wooler.

Related services

Power Factor Correction near you

Working from Unit 4 Home Pl, Coldstream TD12 4DT across the Scottish Borders and North Northumberland.

See the full list of service areas, read about the company, or return to the homepage.

Get a price

Stop paying for reactive power.Start with the survey.

Send us a recent supply invoice and we will tell you whether correction is worth it on your site, and price it properly if it is.

01890 882981
  • Established 1985 | over 40 years' experience
  • SELECT 17074 · ECA 1683735 · SMAS Worksafe SSIP
  • £10m employers' and £5m public liability cover
  • Free quotes supplied

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Related electrical services and areas we cover

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