High Voltage Commissioning

Insights

High voltage engineering, written from site

Technical notes on commissioning, protection, SAP provision and maintenance across UK networks from 11kV to 132kV — written by Stuart Banner, CEO of High Voltage Commissioning Ltd, from fifteen years of field work. Updated monthly.

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UK 11kV switchgear panels with protection relays and test equipment during high voltage commissioning
Protection 7 min

Protection coordination study UK: catching grading errors on site

Grading errors often appear during commissioning because models, relay files and site wiring do not always match. This article explains practical checks before energisation.

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Transformer and HV switchgear undergoing planned maintenance
Maintenance 6 min

Building an HV maintenance regime that actually reduces outages

Calendar-based HV maintenance often means inspecting the assets that do not need it and missing the ones that do. A regime built around duty, condition and consequence gives you fewer outages for the same spend. Here is how we structure one.

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Protection relay panel under secondary injection testing
Protection 7 min

Five protection settings mistakes we keep finding on UK HV networks

Most protection problems we find during commissioning are not relay faults. They are settings and scheme errors that survived design review and only appear under injection testing. These are the five we encounter most often, and how to find them before energisation.

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Senior authorised person operating high voltage switchgear
SAP 7 min

Senior Authorised Person (SAP) provision: what it means and when you need one

A Senior Authorised Person controls the high voltage system, issues safety documents and takes personal responsibility for the safety of others working on it. This is what SAP provision covers, when a project needs it, and what to check before you appoint one.

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HV commissioning engineer testing switchgear inside a substation
Commissioning 8 min

What HV commissioning actually involves — from pre-energisation to handover

High voltage commissioning is not a switch-on. It is a documented sequence of inspections, tests and proving activities that turns installed plant into an asset an operator can safely own. Here is how that sequence runs in practice on UK networks from 11kV to 132kV.

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