Differences Between Residential & Commercial Electricians

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Commercial vs Residential Electricians

As you know, the teams at SESCOS are experts at both residential and commercial electrical work. We’re very aware of the differences between them, but are you? If you’ve ever been curious about the differences between residential and commercial wiring, here’s your chance to learn more.

Q&A: What’s the Difference?


Q. Is Residential Wiring the Same as Commercial Wiring?

A. Although there are some similarities in the way these systems are set up, there are some key differences.

Level of Protection: Residential wiring is usually covered in sheaths. These protect homeowners who perform minor electrical repairs. Residential wiring is generally placed behind walls and in hidden spaces to keep it out of the way and out of view.

Commercial wiring has heavy, protective insulation. This special insulation is known as thermoplastic, highly heat-resistant (TTHT) nylon coating. This heavy insulation protects commercial wiring from caustic chemicals and corrosive materials. Usually, commercial wiring is left out in the open or hanging on rafters to make it easier for electricians to reach it.

Codes and Standards: Residential and commercial electrical systems are expected to meet different standards and electrical codes. Commercial wiring must stand up to high levels of heat, abrasive materials, and corrosive substances. Some commercial buildings are required to have industrial-sized generators as backup systems.

In residential systems, the main concern is the homeowner’s safety. All systems and installations must meet strict safety standards.


Q. Are There Differences in Power Levels?

A. This is another way that commercial wiring differs from residential wiring.

Most homes function on single-phase power systems. These involve two 120-volt wires and one neutral wire. In some cases, they use two-phase, 240-volt circuits to run high-wattage appliances like air conditioners, refrigerators and hair dryers.

Most commercial buildings rely on a three-phase system involving two lower-voltage legs and one higher-voltage one. Typically, this consists of two 120-volt legs and one 208-volt leg. In large setups, the higher-voltage legs can go up to 240 volts. To power a massive industrial complex, you might need two 277-volt legs and one 480-volt leg.


Q. Do the Same Electricians Work on Commercial, Residential and Industrial Systems?

A. All electricians who are licensed by the state have the knowledge and qualifications to work on any electrical project.

With that said, there’s nothing like experience. You should always make sure you hire an electrician who has years of experience handling the type of electrical work you need to have done.

At SESCOS, our highly skilled technicians are experienced in every type of residential, commercial or industrial installation, maintenance, and repair.


Q. What Kind of Training Do Electricians Get?

A. All electricians get highly specialized training. Some attend a technical college, some get undergraduate degrees and others take training through a union apprenticeship program.

Becoming an electrician is very difficult. The training involves years of classroom instruction and hands-on practice. Electricians need an excellent grasp of math, manual dexterity and the ability to think quickly.


Q. What Kind of Licenses Do Electricians Have?

A. In Virginia, every electrician must be certified and hold a state license as a journeyman or master electrician.

In addition to these licenses, an electrical company that does large commercial jobs must have a contractor’s license. Contractor’s licenses are classed as A, B and C. When you hire an electric company for your commercial or industrial property, always ask to see the contractor’s license.


Q. What Do the Different Classifications on a Contractor’s License Mean?

A. Each license specifies the type of project a contractor can do and the monetary size of the project.

  • Contractors with a Class A license can work on any project of any size, scope, and monetary value.
  • Class B license holders can work on contracts or projects that are under $120,000 in value. They can’t do more than $750,000 worth of work in one year.
  • Class C license holders can work on projects worth $10,000 or less. The total value of their contracts must be under $150,000 in a year.


Q. If You Need Expert Help With Any Electrical Problem, Who Should You Call?

A. We think you know the answer to that one.

At SESCOS, we’re always here to answer your questions and answer your calls. If you need emergency electrical services, an energy audit for your business, or help setting up a smart system, we can do it all. Call us today for service you can count on.

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