Arnold Electric, Inc. is an electrical contractor that serves commercial and industrial needs. This is opposed to those that serve residential electrical needs. However, you may notice as you see vans or yellow pages advertisements that electrical contractors will choose certain specialties that break-down into there categories- residential, commercial, and industrial.

Residential
Residential electrical contractors focus on homes, either in doing electrical wiring in new home construction, or serving homes with electrical problems. Homes appliances typically operate on 110 volts with exceptions for 220 volts for major electrical appliances like electrical stoves, central air conditioning, and electric clothes dryers. Something few realize until there is an issue, but a homeowner is responsible for the power line from the power pole to the house. The utility company does not accept that responsibility, so an electrical contractor would address that.

Residential electrical contractors are paid by the homeowners.

Commercial
Like residential, commercial properties operate primarily on 110 and 220 voltages. However, commercial properties have more unique needs. When a business opens or moves, it typically does a remodel of the property they are moving into or has built a new property. Commercial electrical contractors focus on that work, and they do a lot of business with General Contractors who are in charge of new construction. Additionally, commercial electrical contractors work heavily with lighting for interior and external needs including parking lot lighting.

Commercial electrical contractors get paid by the business or from the general contractors.

Industrial
Industrial electrical contractors work with large manufacturing and distribution companies that have very unique power needs. These companies have high voltage equipment with varying voltage requirements. An industrial electrician works heavily from the design of electrical engineers to assure power needs are met.

Unless a new construction facility, industrial electrician are paid by the manufacturing company.

With the explanations given, electrical contractors typically couple either as residential/commercial or commercial/industrial, whatever best suits their business model and expertise. When seeking a contractor, check their advertisements (web sites, business cards, ads, etc.) to see what type of electrical work they do before calling.