Generator Installation

A correctly specified and installed generator is the foundation of any reliable standby power system. Generators London has completed commercial and industrial generator installations across Greater London since 2009, working on everything from small office standby sets to high-capacity prime power systems for industrial clients and critical national infrastructure.

Our CompEx-certified engineers carry out the full scope of work: load assessment, equipment specification, civil and electrical installation, ATS panel commissioning, and handover documentation. This page explains each stage of our installation process and the types of systems we install.

Standby Generator Installation

A standby generator installation provides automatic backup power when the mains supply fails. The set starts automatically, transfers load via an automatic transfer switch, and shuts down cleanly when mains power is restored. This is the most common configuration for offices, retail, hospitality, healthcare and data centre applications in London.

We size standby sets to carry the site's essential load, which may be a sub-set of the total connected load depending on the client's critical power requirements. Our engineers produce a full single-line diagram and load schedule before any equipment is ordered, so you have a complete technical picture before committing to a contract.

To discuss your standby requirement, request a Free Generator Survey and one of our engineers will visit your site.

Prime Power Generator Installation

Prime power systems operate as the primary electrical supply rather than as a backup. They are used on off-grid sites, in areas with unreliable mains infrastructure, and by businesses that want to reduce dependence on the grid for cost or resilience reasons. Prime power sets must be specified to carry 100% of the site load continuously.

We install prime power systems for construction compounds, temporary villages, agricultural sites, remote industrial facilities and urban sites undergoing major refurbishment where the permanent supply has been disconnected. Prime power installations include fuel storage, exhaust systems, acoustic enclosures where required, and full metering and distribution boards.

Automatic Transfer Switches and ATS Panels

The automatic transfer switch (ATS) is the control interface between the mains supply, the generator and the site distribution. When mains voltage drops below threshold, the ATS signals the generator to start and transfers load once the set has reached stable voltage and frequency. When mains is restored, the ATS retransfers load and signals the set to cool down and stop.

We specify and install ATS panels from leading manufacturers including Cummins, ComAp and DSE. Panel ratings range from single-phase 63-amp units for small office installations to three-phase 3,200-amp frames for large industrial sites. Every ATS installation is tested under load before handover to confirm correct operation across all operating modes.

For new installations, we also supply and install manual bypass switches to allow maintenance of the ATS without interrupting the supply. This is a requirement on many critical sites and is good practice on any system where uninterrupted power is important.

Load Assessment and Site Survey

Every installation project starts with a free load assessment and site survey. Our engineers review your connected load schedule, identify motor starting requirements, assess cable routes and containment options, check fuel storage feasibility, and confirm planning or noise constraints that may affect equipment selection.

The output of the survey is a detailed specification covering generator rating in kVA, fuel tank capacity, exhaust routing, ATS panel specification, cable sizes and containment routes, and any civil work required. This document forms the basis of our quotation and gives you the information you need to compare suppliers on a like-for-like basis.

Commissioning and Handover

Commissioning is the final stage of every installation. Our engineers carry out a full functional test of the generator, ATS panel, fuel system and all control circuits before the system is handed over. The set is run under load and the ATS transfer is tested in both automatic and manual modes.

On completion, we issue a commissioning report, a BS 7671 electrical installation certificate, a completed generator data sheet, and an operations and maintenance manual. We also carry out a site induction with your facilities team so that the people responsible for the system understand how to operate it, what routine checks are required, and how to contact us in an emergency.

Get a Free Generator Survey to start the installation process.

Frequently Asked Questions

How long does a commercial generator installation take?

Generator installation timescales depend on site complexity. A straightforward standby installation for a small commercial building can be completed in two to three days. A large industrial prime power system with significant civil work, cable containment and ATS panel installation may take two to four weeks. We provide a programme of works with every quote.

Do you handle planning permission for generator installations?

We advise on planning requirements as part of the site survey. Most standby generators installed within existing buildings or in acoustic enclosures do not require planning permission, but this depends on the local authority, the size of the set and the proximity to residential boundaries. We can prepare technical drawings and noise assessments to support a planning application if required.

What brands of generator do you install?

We install all major generator brands including Cummins, Perkins, Caterpillar, FG Wilson, Kohler, Sdmo and Himoinsa. We are not tied to a single manufacturer, which means we can specify the most appropriate unit for your application and budget rather than defaulting to a preferred brand. We can also supply and install used or refurbished sets for budget-sensitive projects.

Do you provide an electrical installation certificate?

Yes. Every installation is completed to BS 7671 (the IET Wiring Regulations) and we issue an Electrical Installation Certificate on completion. This is required for building control sign-off, insurance purposes and compliance with the Electricity at Work Regulations 1989. The certificate is included in the handover documentation pack.

Can you install a generator in a basement or plant room?

Yes. Basement and plant room installations are common in London due to the scarcity of external space. We design exhaust systems to route flue gases safely to atmosphere, specify forced ventilation where natural airflow is insufficient, and select acoustic enclosures or sound attenuators where noise levels must be controlled. All designs meet the relevant building regulations and manufacturer requirements.