Data Centre – MV/HV Relay Commissioning Engineer (Protection & Control)

This is an excellent opportunity for an experienced MV/HV Relay Commissioning Engineer (Protection & Control) to join a well-established client delivering a hyperscale data centre commissioning programme. This role is highly specialised, focusing on medium and high voltage systems, protection schemes, and relay commissioning within mission-critical infrastructure.

Key Responsibilities

• Execute MV/HV relay commissioning (L2–L4) across critical power infrastructure within a live data centre environment

Commission and test protection relays across:

• Medium Voltage (MV) switchgear
• High Voltage (HV) systems and feeders
• RMUs (Ring Main Units)
• MV/LV transformers
• LV distribution boards and switchboards
• Perform primary and secondary injection testing on protection relays to verify trip characteristics and coordination
• Carry out end-to-end protection scheme validation, including interlocks, alarms, and tripping logic

Undertake HV and MV electrical testing, including:

• Insulation resistance testing (IR)
• Ductor (low resistance) testing
• HV withstand and pressure testing (where applicable)
• Commission and validate networked and integrated protection systems, ensuring correct communication between relays, SCADA, and control systems
• Work on MV switchgear installations within E-Houses, ensuring compliance with design and safety standards
• Interface with OEMs (including Siemens protection systems), Commissioning Authorities (CxA), and multidisciplinary site teams
• Follow structured commissioning procedures using digital platforms (e.g., BIM360 / ACC) and maintain accurate test documentation and reports
• Ensure all works are conducted in line with HV/LV safety rules, permits, and isolation procedures

Technical Requirements

• Strong background in Protection & Control engineering within MV/HV environments
• Proven experience in hands-on relay commissioning and protection scheme testing

In-depth knowledge of:

• Protection relays (overcurrent, differential, distance, etc.)
• MV/HV switchgear and distribution systems

Practical experience with:

• Primary & secondary injection test equipment
• Fault finding and relay configuration
• Demonstrable experience in HV and MV electrical testing methodologies
• HV/LV authorised person with a strong safety-first approach
• Ability to work effectively in live, high-risk, mission-critical environments

Preferred Experience

• Experience in data centres, utilities, or critical infrastructure projects
• Familiarity with Siemens, Schneider, or ABB protection relays
• Experience working with SCADA and networked protection systems
• Knowledge of structured commissioning processes and digital QA/QC systems