Thermal Imaging Electrical Surveys: Find Hidden Faults Before They Become Outages

Your Q1 maintenance window is the moment to prevent avoidable downtime. Thermal imaging turns a routine walk of your electrical rooms into hard evidence of where heat is building, where connections are loosening,and where load is unbalanced. You get insight without shutdown, so you can plan targeted remedials and keep production, tenants, and critical services running.

What thermography means in electrical maintenance

Thermography is the use of infrared cameras to visualise temperature differences on the surface of equipment. In electrical systems, heat is the earliest and most reliable signal of trouble. Loose terminations, overloaded circuits, failing breakers, phase imbalances, and undersised conductors all convert energy into heat. A thermographic survey captures both thermal images and standard photos, then highlights anomalies so you can fix the cause before it becomes an outage or fire.

Thermography can detect overheating components before failure. That is its core purpose. If a lug, breaker pole, or EV charger contact is hotter than its peers under load, you have a developing fault that you can address proactively.

How accurate is thermography for detecting faults?

Thermal imaging is very effective when the survey is set up correctly.

Accuracy depends on:

• Load conditions, circuits should be under normal operating load so faults express as heat.

  
  

• Emissivity settings and distance, the camera must be configured to the surface type, then used at an appropriate angle.

  
  

• A competent thermographer, interpretation matters. Engineers compare like for like phases, similar assets, and ambient conditions.

Most actionable findings do not rely on an absolute temperature number. They rely on temperature delta, the difference between similar points, for example L1 vs L2 vs L3 at a breaker, or one outgoing way vs adjacent ways.

A clear delta, combined with engineering context, is a strong indicator of a defect. Where absolute temperatures are needed, they are estimated using correct emissivity, reflected temperature, and spot size settings.

What a typical thermal survey covers

For a preventive electrical survey, you should expect us to inspect:

• Main switchboards and LV switchgear

• Distribution boards and consumer units

• Panel boards and MCCs

• Control panels and motor starters

• Rising mains and busbar trunking joints

• Critical UPS and server room panels

• EV chargers and feeder pillars

• Building services, for example AHU fans, pumps, and associated isolators

Surveys are non contact. Doors are opened with appropriate safety controls so we can capture images while the system is live and under load.

Inside the report, what you receive and how to use it

A good thermographic analysis report should be practical and audit ready. Ours includes:

• Asset list and location references tied to your boards and circuits

• A paired image for each finding, thermal image and visible light photo

• Temperature readings and deltas, with ambient noted

• Fault type and likely root cause, for example loose termination, overload, imbalance, failed component

• Severity ranking, high, medium, low, with clear action guidance

• Remedial recommendations and, where requested, a proposal with parts and labour

• A summary register so you can track close out

Heat map examples within the report show exactly where the hotspot sits relative to adjacent phases or ways. Severity ranking aligns with electrical risk thinking, anything that presents a fire risk or imminent failure is prioritised for immediate action, and we will make safe where needed.

How long does a thermography survey take?

Duration depends on access and asset count. As a guide:

• Small sites, one to two hours for a handful of boards or an EV hub

• Medium commercial buildings, half a day to a day for 20 to 60 boards

• Large plants and multi building estates, one to three days or a phased programme

Most surveys are completed in normal hours without interrupting operations. Where access is sensitive, we can work early, late, or weekends.

How much does a thermography scan cost?

Costs vary with scale, travel, and reporting requirements. Because no isolation is needed and findings are highly targeted, thermography usually delivers strong ROI. You fix the few things that matter first, then schedule the rest by risk. For a tailored quote, we will scope by board count, criticality, and access constraints, then price accordingly.

Ideal survey conditions for reliable results

• Normal operating load, aim for at least 40 percent of typical load so defects present clearly

• Stable conditions, avoid immediately after large load changes or HVAC start up spikes

• Clean and safe access, keys and permits ready, panels reachable, housekeeping in order

• Lighting and space, so photos are clear and doors can be opened safely

• Known set points, where VFDs, UPS, or chargers have variable demand, schedule when representative

Pre survey readiness checklist

• Confirm live working policy and permit to work requirements

• Provide an up to date board schedule or a floor by floor list, we can help build this if needed

• Identify critical systems and preferred time windows

• Ensure access to risers, plant rooms, server rooms, and EV bays

• Nominate a site escort and point of contact

• Clear obstructions in front of panels and label any known defective doors or interlocks

• Share any recent EICR or maintenance findings so we can cross reference

Turning findings into targeted remedials

Thermography is most valuable when it flows straight into action. At Protest ES Ltd, our engineers can tighten terminations, rebalance loads, replace breakers or lugs, and correct damaged components. High risk items can often be made safe immediately, followed by planned remedial works at the next safe window. Where fixed wiring defects are suspected, we integrate with your EICR programme so that testing and repairs are sequenced efficiently. If you also need broader compliance support, our team delivers electrical testing and can complete EICR remedial works through to certification.

Our approach, scope, and standards alignment

• Standards led practice, carried out by qualified electricians using calibrated thermal cameras, with reporting aligned to good industry practice and integrated with BS 7671 risk language for clarity.

  
  

• Practical scope, we prioritise critical boards and assets, then expand to full coverage. For multi site estates, we cluster surveys and standardise the report format.

  
  

• Rapid follow up repairs, many issues can be corrected on the same visit where safe, otherwise we schedule works promptly and provide evidence of completion.

This model reduces downtime, supports insurer expectations, and gives you a clear audit trail. It complements your broader compliance tasks such as electrical safety inspections and emergency light testing.

Frequently asked questions, answered simply

What is the meaning of thermographic or thermography in electrical maintenance?

it is infrared imaging of live equipment to find heat anomalies that indicate faults so you can intervene early.

How accurate is it?

very effective when assets are under load and interpreted by a competent engineer. Temperature deltas between similar points are the key indicator.

What does a thermographic analysis report include?

paired images, temperature data and deltas, severity ranking, causes, and recommended remedials, all tied to asset locations.

How long does it take?

from one hour for a small site to several days for complex estates, depending on access and volume.

How much does it cost?

price is scope dependent. Most clients see fast payback by preventing outages and fires, ask us for a site specific quote.

Can it detect overheating components before failure?

yes, that is exactly what thermal imaging is designed to do.

Book a survey and reduce downtime risk

If Q1 is your maintenance window, add thermal imaging to your plan. You will gain clear, prioritised actions without switching off your operations, and you will cut the likelihood of surprise outages or fire. Book a thermographic survey with Protest ES Ltd to get a practical report and a rapid remedial plan. If you also have wider compliance tasks in scope, such as electrical testing or EV charger servicing, we can combine visits to minimise disruption.

To summarise, thermal imaging is a fast, non intrusive way to pinpoint loose connections, overloads, and phase imbalance. The right survey conditions and a clear readiness list ensure accurate results. A focused report and swift repairs close the loop, saving time, money, and stress. Reach out to schedule your survey and keep your estate safe and running.