Residential,Cook Electric
Written by Larry Cook

Electrical Subpanels for Commercial Facilities – Part 2

As discussed in Part 1, you will have to consider both the power capacity and distribution of your electrical system as your company expands and its power demand grows. Part 2 will discuss Subpanel Wiring, Subpanel Sizing, and Average Costs.


Subpanel Wiring


A commercial electrical subpanel requires two hot wires connected to a 240-volt double-pole breaker within the main service panel. A neutral wire and a ground wire will also be needed. Called a “three-wire cable with ground,” this cable acts as feeder wires. Its two hot wires provide all the power to a subpanel.


The three-wire cable with ground is connected to a 240-volt main breaker within the subpanel, which then supplies two hot bus bars with power. Connected to these bus bars, circuit breakers are utilized for the distribution of current to branch circuits running from the subpanel.


Commercial electrical subpanels are typically 3-phase panels manufactured for 3-pole, 2-pole, and 1-pole circuit breakers. In addition, most are rated for electrical services up to 600 volts. 3-phase commercial panels require three out-of-phase hot wires, resulting in greater efficiency due to average power being higher compared to single phase. Moreover, 3-phase panels provide steadier continuous power.


Subpanel Sizing


Determined by its application and the power demands of a business, subpanels will vary in capacity. Typically, homes need smaller subpanels 30 to 60 amps in range. In contrast, commercial requirements will be higher, going up to 60 to 100 amps in range. This is because commercial facilities use heavier equipment, such as HVAC systems, compressors, assembly lines, hydraulic lifts, etc.


Average Costs


Commercial subpanels will cost more than those designed for residential purposes. They are manufactured with heavier materials and require more wires. Their load factors are more complex, and they feature more transformers. Needed for industrial applications, commercial electrical subpanels are designed to be very efficient.


The installation cost of a commercial electrical subpanel installation will be lower than the cost of a main service panel upgrade. This is because subpanels are smaller and have less wiring than a main panel. A commercial subpanel installation has an estimated average cost of between $1,000 and $2,500. The total expense will be determined by the subpanel’s size, installation location, and the accessibility of its service area.


Electrical Peace of Mind


Providing professional electricians since 1988 in Maryland, Cook Electric is the company you can rely on for all your electrical service needs. For knowledgeable, fair, honest, reliable, and conscientious service, call Cook Electric today at (410) 266-9040. We will be very glad to help you.