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5 Differences Between a Residential and Commercial Electrical Contractor

May. 4, 2022

differences residential commercial electrical contractor

Any electrician can power up a building with enough time and equipment. That’s what they say until you give them the blueprints for a multi-story mall or office building.

Residential and commercial electrical contractors both work on complex and important jobs, and there’s a lot of overlap between the two. While a commercial electrical contractor often deal with larger-scale projects, they must have a thorough understanding of residential needs because commercial electricians take on residential projects too.

Specialization is key because of all the nuances in the electrical field, which is why there are so many types of electricians.

Types of Electricians

There are more than 20 types of electricians based on their area of specialization, training, and experience.

Here are five of the most common ones.

  • Residential electrician/contractor
  • Commercial electrician/contractor
  • Industrial electrician/contractor
  • Low voltage/electrical communication specialists
  • Automotive electricians

Not every electrician is a contractor, but most residential and commercial electricians do become one. This lets them take on projects individually or as a part of a contractor company.

Here are the five major differences between residential and commercial electrical contractors.

1. Services Offered by Residential vs. Commercial Electrical Contractors

Residential electrical contractors, or domestic electricians, are responsible for the safety, compliance, and finishing of residential electrical installation.

Other responsibilities of residential electricians include:

  • Interpreting technical blueprints
  • Electrical appliance and fixture maintenance and service
  • Diagnosis and repair of electrical faults
  • Residential electrical systems inspection and rewiring

A commercial electrical contractor performs similar tasks on a larger, more complex scale including installing wiring systems, machines, and control panels following the official blueprints.

You are likely to find them in commercial buildings, business locations, public buildings, and factory complexes, among other places. Typically, they’ll handle electrical permitting which is often required in major cities.

2. Equipment and Supplies

Residential and commercial power supplies have an important difference: the power supply type used. Residential electricians typically deal with single-phase systems ranging between 120V-240V.

Commercial electricity is three-phase, where the conductors carry anywhere from 120V to 480V due to high commercial and industrial electrical load power requirements.

This power difference means that the equipment and supplies used are different. Residential electrical systems require thin gauge cabling with less sheathing and insulation. Depending on whether the equipment operates on 120V or 240V, different types of wiring, breakers, and other electrical supplies are used.

Commercial electrical systems require cables with more insulation and sheathing to handle demanding commercial applications. These can include higher voltage and current flow which are expected to perform almost continuously.

Apart from load and safety demands, commercial electrical systems are designed to be more accessible in case of failure. Commercial systems tend to fail more often and require more maintenance, which is why most are installed in easily accessible places with access panels for troubleshooting.

Commercial electrical contractors benefit big-time from having service maintenance contracts.

3. Technical Skills Required

Both residential and commercial electrical technicians start education and training in the same place. They might have worked as apprentices, in trade schools, or have undergraduate degrees, but the basic foundation of all electricians is the same.

Commercial electrical contractors require more experience due to complexity, safety, and reliability factors. Qualifications can include more than 4,000 hours of on-the-job experience and in-depth knowledge about topics like phase and voltage balancing, phase diagrams, and control systems.

States have different competency and certification levels for electricians. Some states even allow DIY electrical wiring for homeowners!

4. Residential vs. Commercial Project Size

Commercial electrical projects are larger than residential projects. From office buildings to malls, and various complexes, these projects take a lot of labor, time, and skill to complete.

However, commercial contractors don’t need to just stick with large commercial properties. Many of them make exceptions for large residential projects, such as large homes and estates, or apartment buildings, which can have systems as complicated as a commercial project.

A commercial electrical contractor can typically take any project that a residential contractor can, but the opposite isn’t necessarily true. This means that they have a wider job market, which serves them well even in these unusual times for contractors due to the pandemic.

5. Standards, Compliance, and Regulations

Electrical compliance standards for contractors are extensive. Residential electrical compliance standards dictate everything from the electrician type for the job to the cables, insulation, and fittings that are used.

Commercial contractors have even more stringent standards and regulations. These include electrical equipment safety standards, personal safety standards they adhere to, and the insurance level for possible disasters caused by electrical faults.

Electrical contractors are usually licensed at the state or municipality level, and the type of certifications vary widely. However, almost all states only issue Electrical Contractor licenses to those with a Master Electrician qualification or businesses that hire a Master Electrician.

From Residential Electrical Contractor to Commercial Electrical Contractor

A qualified and certified residential electrician can become a commercial electrician by fulfilling certification requirements. If you’re already certified as a residential electrician, these can include:

  • Pass the relevant Master Electrician certification exam.
  • Take one (or all) of the National Certifications, which will allow you to take on more industrial projects.
  • 10% of commercial electricians obtain a bachelor’s degree for specialized applications, and even though it’s not necessary, it will increase your job prospects.
  • Practice under a Master Electrician for about 4 years with 2,000 hours of work covered. School can offset around 144 hours per year but check local regulations.

Most jurisdictions follow the apprentice-journeyman-master electrician progression model, issuing separate licenses at each phase, and considering their unique roles. In some states, like Oregon, you need 8,000 hours of on-the-job training as a residential journeyman to become a commercial contractor. So it can take time to get to the commercial electrician level.

Commercial contractors need school education to learn technical skills such as blueprint reading, electrical theory, electrical regulations, first-aid, and safety measures. Many trade unions and organizations such as ELECTRI also offer many advancement opportunities.

Regardless of their differences, commercial and residential electrical contractors face many of the same problems. BuildOps solves some of the biggest ones: organization, reporting, dispatch, quoting, invoicing, and even asset management.