Electrical Thermography

1. Guidance and Considerations

Before commissioning an electrical thermography survey, beneficiaries should consider:

• Scope of inspection – which assets, systems, and voltage levels (LV, HV, or both) are to be included
• Operational conditions – ensuring equipment will be energised and under normal load
• Access arrangements – including whether covers can be safely removed following risk assessment
• Compliance obligations – EAWR 1989, BS 7671, insurance requirements, and internal risk policies
• Auditability expectations – ensuring the survey produces a complete, traceable record of all inspected assets

A well‑defined scope ensures the survey is efficient, safe, and aligned with organisational needs.

2. Selecting Suitable Providers

Choosing a competent provider is essential for ensuring accurate, safe, and meaningful results. In addition to technical competence and equipment standards, beneficiaries must ensure that providers hold appropriate insurance cover for the nature of the work being undertaken.

Competence Requirements

Providers should demonstrate:

• Thermography qualifications – PCN/ITC Category 1 for data capture and Category 2 for analysis and report sign‑off
• Electrical competence – practical experience with electrical systems, understanding of failure modes, and safe working practices
• HV competence (where applicable) – knowledge of HV switchgear, transformers, insulators, and substation protocols

Equipment Standards

Providers must use equipment that:

• Meets the expectations of ISO 18434‑1
• Has optically focusable lenses
• Provides suitable IFOV for the target size and working distance
• Has appropriate thermal sensitivity and temperature range
• Is not a low‑specification or phone‑based attachment
• Is correctly calibrated, with records available

Insurance Requirements

Given the risks associated with working around energised electrical systems, beneficiaries should ensure that providers hold adequate and appropriate insurance cover, including:

• Public Liability Insurance
  • Protects against claims arising from accidental damage to property or injury to third parties during the survey.
  • Cover should be appropriate for the environment (e.g., commercial, industrial, HV substations).
• Employer’s Liability Insurance
  • A legal requirement for companies employing staff.
  • Ensures that personnel working on site are covered in the event of injury.
• Professional Indemnity Insurance
  • Essential for services involving professional judgement, analysis, and reporting.
  • Protects beneficiaries in the event that incorrect interpretation, reporting errors, or omissions lead to financial loss, operational disruption, or safety risks.
  • Cover should be sufficient to reflect the potential consequences of electrical failures, particularly in critical or HV environments.

Beneficiaries should request evidence of insurance and ensure that cover levels are appropriate for the scale and risk profile of the site.

Professionalism and Assurance

Look for providers who offer:

• Clear RAMS and safety documentation
• Transparent pricing and scope definition
• Demonstrable experience in similar environments
• Strong client references or reviews

3. Specifying Survey Requirements

Clear specification ensures the survey meets operational, safety, and compliance needs.

Beneficiaries should define:

• Asset lists and system boundaries
• Voltage levels (LV, HV, or both)
• Access requirements, including whether covers may be removed following risk assessment
• Reporting format, including auditability expectations
• Severity rating framework
• Any insurer‑specific requirements
• Site safety rules and induction requirements

A well‑specified survey reduces ambiguity and ensures consistent, repeatable outcomes.

4. Business Impacts

Electrical thermography supports a wide range of organisational objectives:

Risk Reduction

• Identifies early‑stage defects before they escalate
• Reduces the likelihood of electrical fires, arc‑flash events, and equipment failure

Operational Continuity

• Minimises unplanned downtime
• Supports reliability‑centred maintenance strategies

Financial Benefits

• Reduces reactive maintenance costs
• Supports long‑term asset management and lifecycle planning

Insurance Value

• Provides evidence for underwriting and risk assessments
• Demonstrates proactive risk management
• Supports compliance with insurer‑mandated inspection regimes

For HV systems, early detection of defects can prevent catastrophic failures with significant operational and financial consequences.

5. Safety

Beneficiaries play a key role in ensuring safe survey execution.

They must ensure:

• Safe access to electrical rooms, switchgear, and substations
• Accurate asset information is provided in advance
• Site‑specific safety rules are communicated clearly
• Load conditions are suitable for inspection
• Authorisation is given where covers may be removed following a suitable and sufficient risk assessment

Beneficiaries should also understand that:

• Some assets may not be inspected if safety conditions cannot be met
• Any limitations should be documented in the final report

6. Reporting Criteria

A professional report should be clear, accurate, and fully auditable.

Beneficiaries should expect:

Auditability

• Thermal and visual images for every asset inspected, not only those with defects
• Clear asset identification, location, and reference numbering
• Transparent recording of any access limitations or safety restrictions

Standards Alignment

Reports should follow the principles of ISO 18434‑1, including:

• Clear methodology
• Accurate temperature measurements
• Severity classification
• Traceable image records

Actionable Findings

Reports should include:

• Severity/Priority ratings (e.g. Low, Medium & High)
• Suspected root causes
• Recommended remedial actions
• Notes on safety concerns observed during inspection

A high‑quality report enables beneficiaries to make informed decisions, plan maintenance effectively, and demonstrate compliance to insurers and regulators.