What is commercial electrical work? Read more here.

A guide to understanding what constitutes commercial electrical work, and why you need a specialised contractor for this type of job.

What is commercial electrical work? Read more here.

If you’re looking for an electrician to undertake commercial installation or maintenance tasks, you need to make sure that you hire someone with the appropriate experience and qualifications for the job.

While there are many similarities between residential and commercial electrical work, the differences are extremely important. Here’s a guide to understanding what constitutes commercial electrical work, and why you need a specialised contractor for this type of job.


You might not think that there are many differences between electrical work carried out in commercial or residential properties, but there are.

The design process, installation procedures and legal requirements associated with commercial electrical work require much more expertise than basic domestic repairs and installations. A commercial electrician, therefore, costs more, but this is an important investment in the safety and legal compliance of your facility.

Here are some of the key differences between residential and commercial electrical work.

Complexity of equipment

Domestic electrical installations are usually very straightforward with few requirements other than lighting, heating and running low-voltage appliances. There is no need to power complex machinery or cater to unusual voltage requirements.

The specifications of a factory running 24/7 and using many different types of equipment mean a much more complex design for the electrical installation. They may also require knowledge of more unusual electrical wiring symbols when interpreting blueprints.

Another consideration is the ability to access the wiring and circuits throughout the building for maintenance. In a domestic property, almost all of this is completely hidden within the walls, floor and ceiling to keep residents safe. A domestic electrician may therefore not have experience providing this type of access, which is essential for regular maintenance in complex environments.

Load distribution

Almost all domestic properties use single-phase power, as they have much lower energy requirements than commercial facilities. Single-phase cables contain one live wire, as this is a safe and simple way to provide the necessary power around the building.

On the other hand, commercial electrical wiring generally uses three-phase power. This means that the cables contain three live wires instead of one, allowing more current to flow to equipment that requires a lot of electricity. As well as providing more power, a three-phase system is much more efficient than a single-phase one, which is an important concern for commercial applications.


When hiring a contractor for commercial electrical work, you’ll need to look for a qualified commercial electrician, preferably one with accredited training in any specialist areas that might be relevant for your project.

For example, if you require the design and installation of a complete lighting system, make sure the portfolio of your chosen individual or company includes similar projects. If your facility deals with unusual or hazardous equipment, you’ll benefit greatly from hiring a commercial electrician with extensive experience in a comparable industry.

To qualify as an electrician, whether for domestic or commercial work, a person needs to hold an industry-recognised Level 3 qualification.

The qualifications required to work as a domestic electrician or electrical installer are less strict than those for commercial work. Here’s a quick overview of the different types of qualifications an electrician can have.

Residential electrician qualifications

A residential electrician may have completed a 3-4 year apprenticeship and hold one of the following:

○ Level 3 technical and vocational qualification

○ Level 3 Diploma

A domestic installer will hold a current Level 3 Award in the Requirements for Electrical Installations (17th Edition), and one of the following:

○ Level 3 Award in the Initial Verification and Certification of Electrical Installations

○ Level 3 Award in Approving Electrical Work in Dwellings in Compliance with Building Regulations

Commercial electrician qualifications

On top of the standard requirements to qualify as an electrician, those looking to undertake commercial work will need to take additional training courses.

This allows them to gain the specific knowledge required for this type of work, as well as providing all the necessary information on legal and regulatory requirements.

Some of the additional courses that a commercial electrician might take include:

○ City & Guilds 2357 NVQ Level 3 in Electrical Installation (Buildings and Structures)

○ City & Guilds 2391-52 Initial & Periodic Inspection and Testing Qualification

○ EAL Level 4 Award in the Design and Verification of Electrical Installations

○Portable Appliance Testing (PAT)

Commercial electrician accreditations

As well as holding certain qualifications, many commercial electricians are also registered with industry-recognised accrediting bodies.

This helps to reassure clients that the contractor is committed to providing a safe and reliable service, as well as providing the opportunity for a third-party review of their services.

Fusion’s dedication to our customers is demonstrated through our extensive list of accreditations and memberships of industry-focused organisations, which includes:



○ BAFE Fire Safety Register

○ ISO9001

○ Chas

○ Constructionline

When hiring an electrical contractor, no matter how big or small the task at hand, checking their membership status with some of these organisations will give you the peace of mind that your chosen electrician is able to provide the service required.


A large part of a commercial electrician’s role is providing electrical installation services to organisations in a range of industries.

Here are some of the electrical installation services that you might hire a commercial electrician for.

Lighting, including upgrades to existing designs

Although it’s a necessity in a building, lighting systems can be extremely complicated, especially in larger facilities.

Whether you require the installation of new lights or a complete refurbishment of your existing lighting design, a commercial electrician is the best choice. Not only will they be well versed in the safety requirements for your use case, they will also be able to provide you with the most efficient lighting units and installation design to minimise the cost of lighting your facility.

Electrical installation condition reports

All electrical installations have a limited lifespan and must be regularly inspected to ensure that they are in good working order and safe to use.

A commercial electrician will provide you with a report detailing any recommendations to improve the safety or efficiency of your electrical installation. Regular inspection allows you to avoid dangerous situations in the future and prevent downtime caused by electrical faults or condemned equipment. Reporting is also important when it comes to providing proof of your due diligence in the event of an incident, helping to reduce insurance costs and compensatory payouts.

Power, containment and distribution

Commercial facilities often have extremely high power requirements, and it’s therefore absolutely essential to ensure that the people responsible for the electrical installations are experienced in these higher loads.

From ensuring that the right amount of power is available to your premises from the grid to safely distributing it throughout the facility to where it is needed, a commercial electrician is capable of working with these complex electrical requirements. They will also be able to make sure that all live wires are safely contained to prevent injury while also allowing the necessary access for regular or emergency maintenance.

Electrical periodic testing and inspection

Regular testing and inspection of electrical components helps to ensure that everything is in good working order and safe to use.

Hiring a commercial electrician with the experience and qualifications required to provide periodic testing and inspections will keep your facility safe and compliant with all relevant legislation. They will be able to assess your existing electrical installation, including wiring, lighting and machinery, providing suggestions to improve safety and efficiency wherever possible.

Fire detection, design and installation

A fire detection system is an essential legal requirement in commercial buildings and houses in multiple occupation. When it comes to matters of personal safety, there’s no excuse not to work with a qualified electrical contractor.

Working with a commercial electrician who is able to design and install a suitable fire detection system is extremely important for the overall safety of your people and premises. You can expect them to have in-depth knowledge of the latest Health & Safety legislation and experience providing similar installations in other facilities.

Electrical renovations in existing premises

Renovating the electrical installations in an existing building is a big task, and usually out of the remit of a domestic electrician.

This process involves assessing the current installation, removing old electrical fittings and replacing them with new ones, all while ensuring the structural integrity of the building and the safety of any alterations. A commercial electrician is required to design a new installation that is modern and energy-efficient while adhering to all relevant Health & Safety guidelines for both electrical installation and your industry.

New developments: electrical design and build

Housebuilders, property developers and architects often call on the services of a qualified commercial electrician to design and install the electrical system in one or more new-build properties.

This means knowing how to design the installation from scratch rather than adding to, maintaining or repairing an existing system. To do this, an electrician needs to have in-depth knowledge of the design process, load requirements and safety regulations. It’s common for construction companies to partner with a preferred electrical installer, so it’s important to find someone reliable to save time in the future.

Electrical installation certificates

Whenever new electrical equipment has been installed, an electrical installation certificate (EIC) should be issued. This certificate states that the new installation, alteration or addition is safe to use at the time it was put into service and is important for your Health & Safety records.

To ensure that you receive the correct paperwork for electrical installations, you should always use a registered contractor. As the accrediting body vets and inspects members, this gives you the confidence that all work is up to the high standards expected of the industry.


While electrical installations make up a large portion of the work in a commercial electrician’s day, there are also other services that they perform, and essential skills that they must be able to provide.

Commercial electrical inspection

Regular electrical inspections are needed to guarantee the safety of your building and any electrical installations within.

The use of a proper commercial electrical inspection checklist (CEIC) is absolutely essential to keep everyone safe. Trained commercial electricians such as NICEIC-approved contractors use these checklists to determine the safety of the worksite and what can be done to minimise hazards.

Commercial electrical codes (UK)

Health & Safety is of the utmost importance in any commercial or industrial environment, and the potential dangers of electricity require even stricter regulations.

It’s therefore important to work with an electrical contractor that is experienced in the commercial electrical codes and regulations that are in place in the UK to keep workplaces safe. Complying with Health & Safety legislation is a legal requirement for any electrician, both commercial and domestic. However, you can expect a commercial electrical contractor to possess more in-depth and industry-specific knowledge for industrial or commercial premises.

Commercial electrical certificates

As all electrical systems degrade over time, they should be regularly inspected and tested, usually every 3 to 5 years.

Following the inspection, an electrician should provide a commercial electrical certificate, detailing any:

○ damage to the electrical systems

○ defects and deterioration in the electrical equipment

○ dangerous situations or equipment on the verge of malfunction

○ outdated features that no longer comply with safety regulations

As well as being a legal requirement, commercial electrical certificates help to protect the business owner against a lawsuit in the event of injury caused by faulty electrics.

Understanding commercial electrical wiring

As we’ve seen, commercial electrical wiring can be much more complex than domestic installations.

As well as typically dealing with much larger premises, commercial applications often require high power loads. This means that the design of a commercial installation is usually very different, focusing on safety, efficiency and adaptability for future changes.

Understanding commercial electrical panels

A domestic property will typically have just one electrical panel, allowing the resident to easily reset tripped switches.

For commercial applications, multiple switchboards are often required, allowing for easier control over the various electrical circuits within the facility. Knowing how and where to install these panels, and how to make them easily accessible in the event of a power failure, is key to helping to increase safety and efficiency while minimising downtime.

Three-phase electrical systems

We looked at the difference between single-phase and three-phase electrical systems above, and it’s important that a commercial electrical contractor has the right knowledge, experience and qualifications to work with three-phase electrical installations.

As these systems use three live wires instead of two, they are much more powerful, and therefore more dangerous, than their domestic counterparts. Generally speaking, a domestic electrician will only have experience working with single-phase systems, so hiring a commercial electrician is essential for any work involving three-phase systems.

Commercial electrical blueprints

Electrical blueprints can be complex at the best of times, but commercial electrical blueprints are particularly difficult to interpret. They require the ability to read:

○Architectural floor plans, which provide information on individual rooms and their purpose.

○ Wiring diagrams, showing the path that each wire takes from the electrical panel to a piece of equipment, and which circuit breaker each wire belongs to.

○ Electrical and engineering symbols, which are used to represent certain components within the overall design.

○ Phasing, which means grouping appropriate equipment together on a single breaker for efficient operation and maintenance.

○ Lighting plans, showing the layout and types of fixtures to be used. This is often separate to the wiring plans and requires knowledge of lighting symbols.

○ The specifications manual accompanying the electrical blueprints, which details the electrical requirements and materials to be used.



At Fusion, we’re experts in all aspects of commercial electrical work.

From electrical installations to regular electrical maintenance, our fully qualified commercial electricians have the experience to ensure that your facility is safe, efficient and compliant.

We’ve provided just about any and all electrical services, from upgrading electrical wiring and data cables in a prison to providing a complete electrical installation for a new retail facility. We’ve even worked on conservation projects as specialists in solar power.

If you’re looking to partner with an experienced commercial electrical contractor, get in touch with Fusion. We’re passionate about providing a complete range of commercial electrical services underpinned by care and dedication at all times, helping us to build long-lasting relationships with our clients.

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