Nuisance tripping, overheating neutrals, flickering lighting and unexplained equipment faults usually trace back to power quality. We log your supply with Class A instruments, analyse harmonics, dips, flicker and load profile against BS EN 50160 and ENA G5/5, and hand you a report with mitigation you can act on.
Most sites call an electrician to replace the equipment that keeps failing. Often the equipment is fine — the supply feeding it isn't.
These are classic symptoms of poor power quality — harmonics, voltage disturbances, unbalance or a low power factor — rather than faulty equipment. A survey tells you which, and what to do about it.
Every survey, harmonic study and monitoring campaign is captured and assessed against the specific standard your site and connection are held to.
Defines the limits for voltage magnitude, harmonics, flicker, dips and unbalance at the supply terminals of public distribution networks.
Sets the planning and compatibility limits for harmonic voltage distortion, and the assessment stages for connecting distorting loads.
Governs the connection of embedded generation — solar, CHP, battery — including the power quality studies required before energisation.
Specifies how power quality parameters must be measured; we log to Class A accuracy so results are defensible and comparable.
Defines the instrumentation and technique for measuring harmonics and interharmonics on supply systems and connected equipment.
Specifies the flickermeter used to quantify short-term (Pst) and long-term (Plt) flicker severity from voltage fluctuation.
Power quality covers a range of distinct phenomena, each with its own cause and cure. We capture them all in a single logging campaign and explain what each one means for your site.
Harmonic distortion from non-linear loads — VSDs, UPS, LED drivers, rectifiers
Voltage dips and sags that drop out sensitive control gear and drives
Short over-voltages that stress insulation and power supplies
Fast impulses from switching and lightning that damage electronics
Pst / Plt severity from fluctuating loads causing visible lighting flicker
Uneven phase loading that overheats motors and wastes capacity
Displacement and true power factor driving reactive charges and losses
Frequency variation, relevant to generation and standby transfer
Demand and load profile over time to size supplies and spot peaks
No jargon and no surprises. You know exactly what happens at each stage and what you get at the end.
We scope the symptoms, loads and boards that matter, and agree the monitoring points.
Current clamps and voltage references fitted at the incomer and sub-boards — no shutdown needed.
Continuous logging over a full working cycle, or permanently for continuous monitoring.
Recorded data assessed against BS EN 50160, ENA G5/5 and the limits your connection is held to.
A qualified engineer interprets the findings and traces each disturbance back to its source.
Graphs, trends and an executive summary that a non-specialist can act on.
Specific, costed mitigation — with the expected outcome for each fix.
Where the survey finds an issue, the report specifies the remedy. Typical recommendations and works we deliver:
Tuned passive or active filters to bring THD within ENA G5/5 limits.
Automatic PFC to cut reactive charges and free up capacity.
Redistributing loads across phases to remove unbalance and neutral overheating.
Separating sensitive electronics from dirty, disturbance-generating loads.
Detuned capacitor banks sized to your harmonic environment.
Right-sizing supplies and transformers where demand or losses demand it.
Correcting undersized neutrals and cabling that harmonics have overloaded.
Resolving UPS input distortion and generator compatibility issues.
Capacity and harmonic assessment ahead of charging installs — see EV charger installation.
The right monitoring window and the disturbances that matter depend on your loads and how sensitive your operation is — we scope to the site, not a generic checklist.
Harmonics from UPS and IT load, plus dip ride-through on the critical bus
VSD and welding harmonics, unbalance and power factor across the plant
Dips affecting diagnostic imaging and life-safety systems, per HTM guidance
Lighting flicker, LED-driver harmonics and reactive charges on the bill
Sensitive instrumentation and lab equipment tripping on transients
Rectifier harmonics and demand profiling ahead of connection sign-off
Compressor inrush, unbalance and demand peaks straining the supply
G99 pre-connection studies for solar, CHP and battery installations
Racking, conveyor and charging loads profiled across the whole site
Permanent metering where any interruption carries a heavy cost
Some faults show up in a week of logging; others only reveal themselves over a season. Pick the depth of campaign that matches the problem you are chasing.
A single-point Class A logging campaign at your main incomer, assessed against BS EN 50160.
Simultaneous logging at incomer and sub-boards to isolate exactly where a disturbance originates.
A permanently installed power quality meter with ongoing monitoring, trending and alerting.
Scoped to your site count, connection points and the studies each site requires.
A representative sample of recent work. Full case studies and references available on request.
Class A logging traced elevated THD on the critical bus to UPS input rectifiers; specified tuned filtering to bring distortion within G5/5.
Multi-point survey across drives and the main incomer identified harmonic hot-spots and poor displacement power factor.
Two-week campaign correlated CT scanner drop-outs with recurring voltage dips on the shared feeder.
Flickermeter logging pinned visible LED flicker to Pst excursions from a neighbouring tenant's plant.
Baseline survey and harmonic assessment supporting a G99 application for combined solar and CHP.
Four-week demand profile of compressor plant sized a supply upgrade and flagged phase unbalance.
Survey ahead of expansion quantified rectifier harmonics and profiled charging demand for the DNO submission.
High-speed capture linked intermittent instrument resets to switching transients on a shared distribution board.
Permanent Class A meters installed at incomer and sub-boards with monthly trend reporting and alerting.
Representative examples — site names withheld for client confidentiality. Ask for references relevant to your sector.
Every survey ends in a professional report: harmonic graphs, voltage and flicker trends, load profiles, THD compliance charts, thermal images where relevant, an executive summary and clear recommendations. A sample of the charts included:
Per-harmonic voltage & current distortion against planning limits.
Supply voltage over time, with dips and swells flagged against limits.
Real and apparent power over the cycle to size supplies and spot peaks.
Distortion tracked over time so intermittent breaches aren't missed.
Charts shown are illustrative samples of the report format — not real client data.
We diagnose the electrical network and tell you what to do about it — backed by accreditation, the right instruments and engineering that stands up to scrutiny.
Enrolment 602034000, Part P registered and working to 18th Edition BS 7671.
Surveys scoped to data centres, manufacturing, healthcare and critical sites.
Logging to BS EN 61000-4-30 Class A, so results are defensible and comparable.
Every survey and study is quoted upfront — no open-ended day rates.
Costed mitigation with the expected outcome, not just a folder of graphs.
Infrared inspection of boards and connections — see thermal imaging surveys.
London and the surrounding counties, with every report on your compliance record.
We can design and install the fix, then re-survey to prove it worked.
Accredited power quality survey engineers across Medway and Kent, with every report logged to your compliance record wherever your sites are.
Monitoring retainers above are cheaper over time — but every survey and study is also available as a one-off, fixed price upfront.
| Service | Standard | From |
|---|---|---|
| Surveys | ||
| Single-point snapshot survey (~1 week logging) | BS EN 50160 | £1,450 |
| Multi-point survey (incomer + sub-boards) | BS EN 61000-4-30 | £3,250 |
| Extended 4-week logging campaign | BS EN 50160 | £3,950 |
| Additional logging point (per point) | BS EN 61000-4-30 | £650 |
| Analysis & Studies | ||
| Harmonic study & assessment to G5/5 | ENA G5/5 | £1,650 |
| G99 pre-connection power quality assessment | ENA G99 | £2,650 |
| Load & demand profile report | BS EN 50160 | £1,150 |
| Mitigation design (filters / reactors / PFC) | ENA G5/5 | Custom quote |
| Monitoring | ||
| Permanent Class A PQ meter install (per point) | BS EN 61000-4-30 | £1,850 |
| Monthly monitoring retainer (per meter) | BS EN 50160 | £420 |
| Event investigation & report (per event) | BS EN 61000-4-30 | £395 |
| Multi-site portfolio monitoring | BS EN 50160 | Custom quote |
Plain-English guides and a sample report, free to read — no email required.
See exactly what a finished survey report looks like — charts, findings and recommendations.
View the sample →What harmonics are, what causes them and why they overheat cables and trip breakers.
Read the guide →Why a poor power factor inflates your bill, and how correction pays for itself.
Read the guide →Ten warning signs that your building's supply needs a power quality survey.
Open the checklist →Domestic and single-property jobs — book a live slot instantly. HMO, commercial and portfolio work — send an enquiry and we'll come back with a fixed quote.
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It is a period of monitoring — usually a week or more — where we connect a Class A instrument to your supply and log parameters such as voltage, harmonics, dips, swells, flicker, unbalance and load. The data is assessed against BS EN 50160 and, where relevant, ENA G5/5, so you get an objective picture of your supply rather than a guess.
Harmonics are generated by non-linear loads — variable speed drives, UPS, LED drivers, rectifiers and EV chargers. They overheat neutrals and transformers, cause nuisance tripping and waste capacity. G5/5 sets the limits your site must stay within, and our survey shows whether you are inside them.
A snapshot survey runs for around a week, which captures a full working cycle. Where a fault is intermittent or seasonal — or where BS EN 50160 assessment is needed — we log for two to four weeks, or install a permanent meter for continuous monitoring.
Both are Energy Networks Association Engineering Recommendations. G5/5 sets the limits for harmonic distortion a customer may inject into the network. G99 governs connecting embedded generation such as solar, CHP or battery, and often requires a power quality study before the DNO will energise the connection.
Yes. The report does not stop at findings — where we identify a problem we specify the fix, whether that is harmonic filtering, line reactors, power factor correction, a supply upgrade or reconfiguring loads across phases, with the expected outcome for each.