Data Centres
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving data centres.
Discover MoreDeteriorating Switchgear Identified by Thermal Imaging
- ✔ PCN/ITC L2+
- ✔ ISO 18434-1
- ✔ Fully insured
- ✔ UK-wide
Understanding Deteriorating Electrical Switchgear
Electrical switchgear controls, protects and isolates electrical circuits across low-voltage and high-voltage systems. Thermal imaging can identify abnormal operating patterns associated with deteriorating contacts, joints, internal connections, accessories and other current-carrying components.
Switchgear defects may develop gradually through mechanical wear, repeated operation, thermal cycling, contamination, corrosion, loss of contact pressure, insulation ageing or declining connection integrity. Many internal conditions are not visible while equipment remains enclosed and energised.
Our electrical thermal imaging surveys assess accessible switchgear while systems remain in service and operating under representative load. This page explains how deterioration may present thermally, why comparative patterns matter and why the precise internal cause may require further investigation following safe isolation.
The consequences vary from a developing maintenance issue within an LV switch to loss of supply, arcing or extensive damage within critical main switchboards, RMUs and 11kV switchgear. The significance therefore depends on the affected asset and the services it supports.
Effective assessment considers electrical load, phase comparison, switchgear design, the current path, enclosure effects, operating history and consequences of failure. An external temperature pattern may indicate an internal issue without revealing the exact component responsible.
For a wider overview, visit our Common Electrical Faults Identified by Thermal Imaging guide. Related connection mechanisms are covered in our High-Resistance Connections guide.
Page Contents
- What Is Deteriorating Switchgear?
- Why Deteriorating Switchgear Generates Heat
- Thermal Imaging Examples
- Causes, Indicators, Equipment and Risks
- Where Switchgear Deterioration Occurs
- Corrective Action and Follow-Up
- Why Specialist Thermal Interpretation Matters
- Why Choose Red Current
- Industry Applications
- Frequently Asked Questions
What Is Deteriorating Switchgear?
Switchgear deterioration describes declining condition within switches, circuit interrupters, contacts, joints, mechanisms, insulation systems and associated assemblies. The equipment may continue operating while thermal behaviour changes under load.
Thermal imaging can identify heat transferring to accessible surfaces from internal components. The visible pattern may indicate the location of abnormal behaviour, but the enclosure can spread or obscure heat and prevent a precise diagnosis from the thermogram alone.
The finding should be considered alongside load, equipment design, comparable phases or units, operating history and manufacturer guidance. Safe inspection and appropriate testing may then be needed to confirm the internal cause.
Why Deteriorating Switchgear Generates Heat
Contact and Joint Resistance
Deteriorating contacts, joints or connection interfaces can increase resistance and generate localised heat while current flows through the switchgear.
Mechanical and Material Ageing
Repeated switching, loss of contact pressure, contamination, corrosion and insulation ageing can alter electrical and thermal performance over time.
Heat Transfer Through Enclosures
The measured surface temperature may be displaced from the internal source. Switchgear construction, ventilation and thermal mass all influence the pattern visible to the thermographer.
Thermal Imaging Examples of Deteriorating Switchgear
Switchgear deterioration can be inferred from unequal cable or connection temperatures as well as direct surface heating. The examples below add an RMU cable comparison and LV switch-to-busbar assembly to the LV main-switch and 11kV examples shown above.
Important: External thermal patterns can indicate an internal switchgear issue but do not always reveal the exact failing component. Loading, phase comparison, construction, current path and appropriate inspection following safe isolation must also be considered.
Deteriorating Switchgear Characteristics
Common Causes
- Contact wear and deterioration
- Loss of contact pressure
- Repeated switching operations
- Corrosion or contamination
- Loose or high-resistance joints
- Insulation and material ageing
- Poor maintenance or adverse environment
Typical Thermal Indicators
- Localised enclosure hotspot
- One phase or cable warmer than equivalents
- Switch-to-busbar temperature rise
- Heat displaced from an internal source
- Increasing differential during repeat surveys
Affected Equipment
- LV main switches and switchboards
- 11kV switchgear
- Ring Main Units (RMUs)
- MCCs and distribution switchgear
- Busbar and switch assemblies
- Breaker and isolator compartments
- Cable termination chambers
Potential Risks
- Loss of supply or switching function
- Electrical arcing
- Damage to adjacent equipment
- Unplanned outage
- Reduced system reliability
- Extended repair times
- Fire risk
Concerned About Abnormal Switchgear Temperatures?
Red Current can assess accessible LV and HV switchgear under representative load, provide clear thermal and visual evidence, and deliver an independently reviewed report with prioritised recommendations. We also support electrical testing companies requiring specialist thermography.
Where Switchgear Deterioration Commonly Occurs
Thermal anomalies may occur within LV main switches, distribution switchboards, MCCs, circuit-breaker compartments, busbar chambers, Ring Main Units, 11kV switchgear, isolators and associated cable termination compartments.
The anomaly may appear directly over a switch body, at a switch-to-busbar interface or indirectly as unequal temperatures on comparable incoming or outgoing cables. Understanding the current path is essential when tracing a likely internal source.
The four examples on this page span LV and 11kV switchgear together with an RMU and switch-to-busbar assembly. Together they demonstrate that deterioration can present as direct heating or as a comparative difference elsewhere in the connected circuit.
Corrective Action and Follow-Up
Thermal imaging identifies switchgear that warrants investigation; it does not replace safe isolation, internal inspection, maintenance or electrical testing by appropriately competent personnel. Corrective action may include inspection of contacts and joints, cleaning, adjustment, replacement of degraded components or planned switchgear refurbishment.
Where practicable, a follow-up thermal inspection under comparable operating load can help verify that corrective work has resolved the abnormal pattern. For HV equipment, investigation and maintenance should follow the site’s safety rules, switching procedures and manufacturer guidance.
Need a Survey or Independent Verification?
Red Current can provide a specialist electrical thermal imaging survey or follow-up verification inspection under representative operating load. Our electrically qualified, ITC/PCN certified thermographers provide clear thermal and visual evidence, independently reviewed reporting and prioritised recommendations, while your appointed electrical contractor or HV service provider remains responsible for isolation, internal investigation and remedial work.
Why Specialist Thermal Interpretation Matters
The Hottest Surface May Not Be the Source
Heat can conduct through switchgear housings and internal structures. The visible hotspot may be displaced from the deteriorating contact, joint or component.
Comparable Circuits Provide Essential Context
Ring cables, adjacent phases and similar switchgear operating under comparable load can reveal differences that would be difficult to interpret from one temperature reading alone.
External Thermography Has Limits
Closed compartments and insulation systems can mask internal conditions. Thermography directs further investigation but should not be presented as a complete internal diagnosis where the source is not visible.
Interpretation and Reporting Create the Value
The value of an electrical thermal imaging survey lies in converting thermal evidence and equipment context into a defensible maintenance decision. Red Current’s assessments draw on electrical expertise, ITC/PCN certification, structured review and an in-house knowledge base developed from years of reporting data and millions of thermal images.
Specialist Support for Electrical Testing Companies
Red Current can provide specialist LV and accessible HV thermographic inspection, interpretation and reporting while the electrical or HV testing contractor retains the client relationship and responsibility for internal testing or remedial work.
Why Choose Red Current for Electrical Thermography?
Realising the full value of an electrical thermal imaging survey depends on the competence of the thermographer, the quality of the inspection process and the clarity of the final report. Red Current combines electrical knowledge, certified thermography expertise and structured quality assurance to provide findings that can be understood, prioritised and acted upon.
Qualified Thermographers
Our electrical thermal imaging surveys are undertaken by electrically qualified, ITC/PCN certified thermographers. These recognised certification schemes provide structured training and assessment in infrared thermography, while our electrical qualifications and field experience support safe, technically informed inspection of live electrical systems. Thermographer competence matters because image capture, measurement, interpretation and reporting must be considered together.
Read more about why ITC/PCN thermography certification and surveyor competence matter.
ISO-Aligned Survey and Reporting
Our survey and reporting processes are aligned with ISO 18434-1, supporting a consistent approach to inspection, analysis and communication of findings. Reports are prepared to give maintenance teams clear evidence, appropriate context and practical priorities.
See our guidance on electrical thermal imaging standards, reporting and survey requirements.
Reviewed, Actionable Reporting
Thermal images alone do not provide a maintenance strategy. Our reporting process turns observations into documented findings with supporting thermal evidence, priority classifications and recommendations that can be used by facilities teams, insurers and electrical contractors.
Find out whether an electrical thermal imaging report can support insurance requirements.
Experience Across LV and HV Systems
Switchgear ranges from LV main switches and MCCs to RMUs and 11kV assemblies. Red Current delivers electrical thermography across commercial, industrial and high-voltage environments, helping ensure each anomaly is assessed in the correct asset, load and operational context.
Explore our common electrical faults guide and high-voltage thermal imaging surveys.
Specialist support without competing for remedial work: Red Current can provide the thermographic survey, analysis and report while the client’s appointed electrical contractor or in-house electrical team completes any required investigation and remedial work.
Industries Affected by Deteriorating Switchgear
Deteriorating switchgear can affect every sector where electrical distribution, isolation and protection are critical to continuity, safety or production.
Manufacturing Facilities
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving manufacturing facilities.
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High Voltage Substations
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving high voltage substations.
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Hospitals & Healthcare Facilities
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving hospitals & healthcare facilities.
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Distribution Centres
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving distribution centres.
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Food Manufacturing Facilities
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving food manufacturing facilities.
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Commercial Offices
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving commercial offices.
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Schools, Colleges & Universities
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving schools, colleges & universities.
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Shopping Centres & Retail Parks
Thermal imaging can identify abnormal switchgear behaviour and developing reliability concerns within electrical systems serving shopping centres & retail parks.
Discover MoreFrequently Asked Questions
Common causes include contact wear, repeated switching, loss of contact pressure, thermal cycling, contamination, corrosion, insulation ageing, connection deterioration and adverse environmental conditions.
Thermal imaging can identify abnormal surface or comparative temperature patterns that may indicate an internal issue. The precise cause may require safe internal inspection and further testing.
A difference between comparable ring cables under similar load can indicate abnormal behaviour within an RMU or associated connection. Load and circuit conditions must be checked before reaching a conclusion.
Not always. Heat can transfer through internal structures and enclosures, so the visible surface pattern may be displaced from the source.
Yes. Continued deterioration can contribute to loss of switching function, connection failure, arcing, equipment damage or unplanned loss of supply.
No. Thermography is a condition-monitoring tool that helps direct maintenance. It does not replace safe isolation, internal inspection, testing or manufacturer-specified servicing.
Priority considers the thermal pattern, loading, equipment type, voltage level, asset criticality, possible failure mechanisms and consequences of an outage or electrical incident.
Specialist thermographers understand heat transfer, comparative analysis, switchgear construction and operational context, then communicate findings through consistent reporting and actionable recommendations.
For broader survey questions, visit our Electrical Thermal Imaging Survey FAQs.
Switchgear Deterioration Requires Informed Investigation.
Thermal imaging can reveal abnormal switchgear behaviour before visible failure, but external temperature alone does not identify every internal cause. Representative loading, comparative analysis, equipment knowledge and appropriate investigation are essential if findings are to support sound maintenance decisions.
Red Current provides specialist electrical thermography for end users, facilities teams, insurers and electrical testing companies throughout the UK. Contact us to request pricing, obtain a sample report or discuss a subcontract survey requirement.
