Our services
High Voltage
Specialist High Voltage Electrical Services
Scotts Electrical Services provides specialist High-Voltage (HV) electrical services to industrial, commercial, infrastructure, utility and critical-power clients throughout the UK and Ireland.
Our HV department provides a complete range of services covering the installation, testing, commissioning, maintenance, fault-finding and refurbishment of HV and MV electrical systems.
Our experienced engineers and technicians work across HV cables, switchgear, transformers, substations, protection systems and earthing systems, with a strong focus on safety, technical standards, quality workmanship and minimising disruption to our clients’ operations.
Transformer maintenance experience
Tailored HV callout support
HV Installation, Commissioning & Energisation
Scotts Electrical Services provides complete installation services for HV substations, switchgear, transformers, HV and LV cabling, protection systems, control equipment and earthing infrastructure.
Our engineers support projects from initial planning through to installation, testing, commissioning and controlled energisation. Testing can include mechanical operation, electrical functionality, interlocks, trip and close circuits, contact resistance, insulation testing and verification of protection and control systems.
Before energisation, the installation and associated documentation are inspected and verified to confirm the system operates correctly and safely and is ready for service. Test results, commissioning records, inspection reports and relevant certification are supplied as applicable.
HV & LV Cable Installation, Jointing & Termination
Scotts Electrical Services provides complete HV and LV cable installation services for industrial, commercial and infrastructure projects.
Our capabilities include cable pulling and laying, containment, cleating, identification, jointing and termination. We support new installations, extensions to existing networks and the replacement of ageing or damaged cables.
Our trained cable specialists complete joints and terminations using approved systems and manufacturer-specific procedures. We follow up with the appropriate inspection and VLF testing before returning the cable to service.
HV Upgrades, Refurbishment & Fault Response
We support the modification, upgrading and refurbishment of existing HV electrical systems, including the replacement of ageing switchgear, transformers, protection equipment, cables and associated infrastructure.
Where complete replacement is not required, targeted upgrades can help extend the useful life of existing assets while maintaining the safety and security of the overall HV installation.
For electrical faults and unplanned outages, our engineers can help identify and isolate faults, test, repair, and restore service. Scotts also operates a tailored 24/7, 365-day HV callout arrangement for clients with an agreed support plan and dedicated callout number.
HV Preventative Maintenance
Scotts Electrical Services provides structured preventative maintenance programmes that improve the reliability and availability of HV electrical systems.
Maintenance can cover substations, switchgear, transformers, cables, protection systems, earthing and associated equipment. Regular inspection and testing help identify deterioration, mechanical problems, loose connections and insulation issues before they develop into major failures.
Programmes can be tailored around each client’s operational requirements and equipment criticality, helping to reduce unexpected failures and support electrical compliance and insurance requirements.
Transformer Maintenance & Condition Assessment
Scotts Electrical Services carries out planned and reactive maintenance on distribution and power transformers, with experience covering equipment from 3.3 kV to 110 kV.
Our services can include visual inspection, electrical testing, connection checks, condition assessment and transformer oil sampling. Samples are sent for laboratory analysis to identify moisture, contamination and indicators of insulation deterioration.
We produce a report for each transformer sample, providing results you can use for condition trending and informed maintenance decisions. This helps clients address potential problems early, protect critical assets and reduce the risk of unexpected outages.
HV Cable Testing & Diagnostics
We provide comprehensive testing and diagnostic services for newly installed, repaired and existing HV cable systems.
Testing can be completed during commissioning, following cable repairs or as part of planned maintenance and condition assessment. The appropriate testing method is selected according to the cable type, voltage level, installation and project requirements.
We also provide cable identification and underground route tracing when existing routes must be confirmed before excavation, cable replacement, network modification, or fault investigation. Clients receive documented information on the condition and integrity of their cable systems.
Protection Relay Testing
Scotts Electrical Services tests and verifies HV protection systems using primary and secondary injection techniques, where applicable.
Our engineers can test protection relays, trip circuits and associated equipment to verify operating characteristics, protection settings and correct circuit-breaker operation.
Protection testing can form part of a new installation, commissioning, planned maintenance or an investigation following protection operation. Our engineers have experience across a wide variety of protection relays, installations and applications, and are supported by an extensive range of specialist test equipment.
Partial Discharge Testing
Partial discharge can indicate deterioration within high-voltage insulation systems before a major failure occurs. Our trained engineers use specialist diagnostic testing to assess cables, switchgear and transformers for developing weaknesses.
Partial discharge is sometimes described as “electrical rust” because, once present, it can progressively worsen. Early identification lets clients plan targeted maintenance, reduce the risk of costly breakdowns, and protect the long-term integrity of their electrical systems.
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HV Condition Surveys
Scotts Electrical Services provides detailed condition assessments of existing HV electrical installations.
Surveys can cover individual items of equipment or complete HV installations. They help clients understand their assets’ current condition, identify areas needing attention, and develop future maintenance or replacement programmes.
Before the survey, we explain the recommended scope of the assessment. Once the site survey is complete, clients receive a full report and briefing on the findings, helping them evaluate the present and future requirements of their power infrastructure.
HV Design & Technical Consultancy
Our experienced team provides technical support and consultancy for HV electrical projects from initial concept through to installation and commissioning.
We can assist with HV and LV system modifications, equipment selection, cable systems, substations, protection, earthing, maintenance requirements and project planning. We work alongside clients, principal contractors, consultants and other electrical contractors to provide specialist HV input where required.
Scotts is also a member of the National Equipment Defect Reporting Scheme, providing access to current equipment incident and safety information. We have extensive experience working alongside NIE to ensure that fault levels and overcurrent and earth-fault protection settings are properly considered.
Doscuss Your High Voltage Requirements
Whether you need a new HV installation, planned maintenance, a condition assessment, a system upgrade, or emergency fault support, our experienced team can provide the specialist services your site needs.
Contact Scotts Electrical Services to discuss your HV system and operational requirements.
