Generator Commissioning: What to Expect and Why It Cannot Be Skipped
A generator that has been installed but never properly commissioned is not a backup power system, it is a liability. Generator commissioning is the critical final step that confirms your new installation will actually perform when mains power fails. Yet it remains one of the most frequently overlooked stages in standby power projects across the UK.
This guide explains what commissioning a diesel generator involves, what a proper generator commissioning checklist should cover, and why no installation should be signed off without it.
What Is Generator Commissioning?
Generator commissioning is the structured process of inspecting, testing, and verifying a newly installed generating set and its associated systems. This is done before it enters service. It is distinct from factory testing, commissioning a diesel generator takes place on site, under real conditions, with the full electrical installation in place.
The process is carried out by a qualified engineer and results in a formal commissioning record that documents the system’s performance. This record is essential for regulatory compliance, manufacturer warranty, and ongoing maintenance reference.
What Does a Generator Commissioning Checklist Include?
A thorough new generator commissioning checklist will cover three main areas:
- Pre-commissioning inspection: Verifying that the installation matches the design specification, that all electrical connections including earthing are correct, that fuel, oil, and coolant levels are correct, and that control panel settings are properly configured.
- Functional testing: Confirming that the generator starts automatically on a simulated mains failure, that the automatic transfer switch (ATS) operates correctly and transfers load within the required time, and that all engine protection shutdowns and generator protection relays function as intended.
- Generator site testing under load: Applying a controlled load, typically via a portable load bank, to verify that the generator delivers its rated output, that voltage and frequency remain stable, and that engine temperatures stay within limits during extended operation.
Generator Commissioning in the UK: Who Should Do It?
Commissioning should always be carried out by an engineer with specific experience of diesel generating sets and UK power standards. Many manufacturers require commissioning to be completed by an approved partner as a condition of warranty.
At Lance Power, we carry out generator commissioning and generator site testing across the UK. For clients in data centres, healthcare, manufacturing, and commercial property. Every commissioning visit results in a full acceptance testing record issued to the client at handover.
If you have a new installation that requires commissioning, contact the Lance Power team to discuss your requirements.
