Electrical Thermography

Electrical Thermography Overview

Background

Electrical thermography is a non‑intrusive diagnostic technique used to assess the condition of electrical distribution systems by detecting abnormal temperature patterns. Electrical components that are deteriorating, overloaded, contaminated, or suffering from loose or high‑resistance connections often generate excess heat long before failure occurs. Thermal imaging enables these issues to be identified safely, quickly, and without interrupting operations.

Across the UK, electrical thermography has become an essential component of preventive maintenance strategies. It complements—but does not replace—traditional inspection and testing methods such as Electrical Installation Condition Reports (EICRs). While EICRs verify compliance and electrical safety, they cannot detect many early‑stage thermal anomalies. Thermography fills this gap by providing real‑time insight into asset condition under normal load.

In parallel with the growth demand for electrical thermography, there has been an increase in low-cost, low-specification thermal imaging cameras entering the market. This in turn has led to cases in which electrical inspections have been carried out by untrained/inexperienced practitioners using ill-suited equipment, thus rendering the inspections ineffective and often involving the use of unsafe working practices.

The discipline is supported by international standards such as:

• ISO 18434‑1:2008 – Condition Monitoring and Diagnostics of Machines – Thermography
• ISO 18436‑7:2014 – Thermography Personnel Certification

These standards define expectations for survey methodology, reporting, and practitioner competence.

Typical Facilities and Industries That Benefit

Electrical thermography is widely applicable across all sectors where electrical reliability, safety, and continuity of service are critical. Beneficiaries include:

• Commercial buildings (offices, retail centres, data centres)
• Industrial and manufacturing facilities (production lines, process plants, food manufacturing)
• Healthcare and education (hospitals, laboratories, universities)
• Utilities and infrastructure (water treatment, energy networks, transport hubs)
• High Voltage (HV) substations and private networks
• Property and real‑estate insurers, particularly where thermography supports risk reduction, evidence‑based underwriting, and compliance with policy conditions
• Facilities with insurance‑driven maintenance requirements
• Sites with critical uptime obligations (telecoms, IT, logistics, cold storage)

Benefits of Electrical Thermography

Electrical thermography provides a range of operational, financial, and safety benefits:

Safety & Compliance

• Early detection of overheating components, loose or high‑resistance connections, overloaded circuits, and mechanical deterioration
• Supports compliance with EAWR 1989, BS 7671, and insurer requirements
• Enables safe, non‑intrusive inspection of energised equipment

Operational Reliability

• Identifies defects that traditional inspections may not reveal under load
• Reduces the likelihood of unplanned outages and equipment failure
• Provides a clear audit trail of asset condition for maintenance planning

Cost Efficiency

• Prevents costly breakdowns and business interruption
• Enables targeted, condition‑based maintenance rather than reactive repair
• Supports long‑term asset management and lifecycle planning

High Voltage (HV) Specific Benefits

• Detects issues such as poor connections, high‑resistance joints, cooling anomalies, and component imbalance
• Helps prevent catastrophic failures and system‑wide outages
• Provides prioritised remedial recommendations for critical infrastructure

Further Guidance

To support both practitioners and organisations commissioning electrical thermography, the UKTA provides two dedicated guidance sections. These can be accessed directly from this page.

Guidance for Practitioners

For thermographers, electrical engineers, and maintenance professionals conducting electrical thermography surveys.

This section outlines recommended training pathways, equipment selection, inspection methodology, safety considerations, and reporting criteria. It is designed to promote consistent, high‑quality practice aligned with recognised standards.