FAQs

Got questions about generators, hire, compliance or servicing? Find quick answers below, organised by topic.

What are the noise emission limits for a generator...

There is no single national limit — conditions are set by local planning authorities based on background noise at the site. Typical conditions in mixed commercial/residential areas require that the generator does not increase background noise by more than 5 dB(A) above the pre-existing level, or does not exceed an absolute level at the nearest sensitive receptor. iPower designs acoustic packaging to meet the specific condition set by your local authority.

Is there a requirement to test a standby generator regularly

Yes. For life safety generators, testing is both a regulatory and insurance requirement. BS 8519 requires periodic load testing. The standard recommendation for all standby generators is a weekly no-load test run and annual full load bank test. For life safety facilities, test records are subject to inspection by NHS Estates, fire authorities and insurers. iPower's service contracts include all required testing and full documentation.

What environmental permits might apply to a diesel generator

In Great Britain, generators rated above 1 MWth may require registration under the Medium Combustion Plant Directive (MCPD), setting limits on NOx, SO2 and dust. Standby plant used fewer than 500 hours per year may benefit from reduced requirements. In Ireland, similar provisions apply under the Industrial Emissions Directive. iPower advises on the emissions class of specified engines and any permit obligations that may arise.

Do I need planning permission to install a standby generator

In many cases, yes — particularly for externally installed generators in a canopy, compound or container. Requirements depend on size, location relative to existing structures, noise impact and visual impact. Permitted development rights may cover small installations in certain circumstances. iPower advises on likely planning requirements for your specific installation and can support the planning application.

What is G99 and when does it apply to a generator...

Engineering Recommendation G99 governs the connection of Power Generating Plant to the UK public distribution network. It applies when a generator runs in parallel with the mains — for peak load reduction, export, or closed transition transfer. Generators used solely for standby (open transition, never parallel with mains) generally do not require G99 compliance. If parallel operation is intended, G99 applies — requiring a DNO application, compliant protection relays and a DNO witness test before going live. iPower manages the full G99 compliance process.

What legislation governs standby generator installations...

Key standards and regulations include: - BS 8519:2010 – Life safety power systems - BS EN 60947-6-1 – Transfer switching equipment - BS 7671 (IET Wiring Regulations, 18th Edition) – UK electrical installations - IS 10101 (NSAI) – Irish wiring standard (based on IEC 60364) - Building Regulations Part B (UK) / Technical Guidance Document B (Ireland) – Fire safety - EN ISO 8528 – Generator set performance standards - G99/G100 – Connection of embedded generation to the UK distribution network - Planning legislation – Noise, emissions, visual impact (varies by local authority)