Commercial Electrical Service covers the installation of electricity in business settings like retail stores, restaurants and hotels. These electrical systems include lighting solutions and other energy-efficient options to support businesses’ power needs.
They also address power distribution through breaker panels and other switchgear. In addition, they prioritize safety protocols and code compliance.
MC wiring is commonly used in commercial buildings for lighting, outlets and appliances. It consists of multiple insulated copper conductors wrapped in a metal sheath, which provides protection against physical damage, moisture and fire. This rugged construction makes it an ideal electrical wire for demanding industrial settings, where power is channeled to complex machinery and equipment.
In contrast, residential electricians often use Type NM (non-metallic sheathed) wiring for branch circuits. It is inexpensive, easy to work with and doesn’t require special tools. However, it is not well-suited for outdoor use and cannot withstand the wear and tear of frequent use in demanding environments.
Type MC wiring also has unique properties that make it suitable for applications where reliability and safety are critical. The conductors are encased in an aluminum interlocking armor that helps resist the impact of mechanical damage. It also offers superior fire resistance, with the sheath preventing heat from reaching the conductors and protecting them for up to two hours in the event of a fire.
Additionally, MC cables are available in various gauges and with different number of conductors. The most common, 12-2 MC cable, is ideal for a wide range of general electrical applications in exposed and concealed work, including wiring within walls and ceilings. It includes three or four compact stranded aluminum XHHW-2 conductors cabled together and a bare or insulated grounding wire to meet the requirements of NFPA 70, National Electrical Code (NEC).
When installing Type MC wiring, it is important to follow all safety protocols. It is also essential to ensure that the cable is not energized prior to working with it. Once the installation site has been prepared, installers should carefully score and remove the metal sheathing before stripping back the insulation using a wire stripper. After the bare wires are exposed, they should be cleaned and checked for signs of corrosion or damage. Lastly, the installer should use an appropriate fitting that is listed for use with MC wire. Some fittings may not require an insulating bushing while others will include a bushing by design.
Type MI Wiring
Electrical wiring is the means by which currents are transported in a commercial electrical circuit. These wires connect the breaker panel to outlets, switches and other devices. Typically, there are multiple types of electrical wires used in the circuit, and each one has its own unique purpose.
The electrical wiring is made up of various components including conductors, conduit raceways and busways. Choosing the right wiring methods is crucial for the safety and performance of a power distribution system. Examine industry standards and physical characteristics for each type of wiring to determine which is the best fit for your project.
Non-Metallic Sheathed Cable (NM Wiring)
Also known as Romex, NM wiring is the most common wire used in residential settings. It consists of two or more insulated conductors and a bare grounding wire, all enclosed in a plastic sheath. It’s suitable for circuits with voltages up to 120/240 volts and is generally used in lighting and outlet circuits.
Rigid Metal Conduit (RMC Wiring)
Unlike NM cable, RMC is designed to be installed in a rigid conduit. It’s an ideal option for applications where the cable will be exposed or vulnerable to physical damage. RMC is available in a variety of different sizes and materials to suit any project’s requirements.
Electrical Metallic Tubing (EMT Wiring)
Similar to RMC, EMT is a versatile wire that can be used in many types of projects. It’s especially useful in high-rise buildings, where space is limited and the cables will be running along vertical surfaces. EMT is available in a wide range of sizes and materials, including galvanized steel, aluminum and PVC.
Mineral Insulated Cable (MI Wiring)
For projects that require the use of thermocouple wires, MI cable is a good choice. It consists of a pair of (or up to four in duplex) insulated copper conductors with dry magnesium oxide powder filling the spaces between them. This helps to isolate the thermocouple wires from each other and from the external sheath.
Another key benefit of MI cable is that it’s suitable for installation in a fabricated duct or plenum. These ducts or plenums are specifically fabricated to transport environmental air, and they can either be fabricated on site or brought in pre-fabricated from the manufacturer. Rigid Metal Conduit (RMC cable), Intermediate Metal Conduit (IMC) or Mineral Insulated Cable (MI cable) with a metal sheath can be used in these ducts.
Type THWN Wiring
When working on a commercial electrical service project, electricians will encounter multiple different types of building wires. It’s important to understand the differences between each type in order to choose the right one for a given task. Choosing the wrong type of wire can cause damage to the circuit and lead to overheating and fires.
THHN is a common type of building wire for use in commercial contexts due to its high heat resistance and water protection. This makes it ideal for applications where the wire may be exposed to corrosive materials and environments.
This type of building wire is a solid conductor that features a PVC insulation and a nylon jacket. It can withstand high temperatures and passes the FT1 flame test. It can also withstand grease, oil and abrasion. It’s often used for light fixtures and outlets as well as electrical conduit runs.
Another common use of THHN is for grounding wires. This is an essential step for ensuring the safety of individuals and equipment within a given facility or machine. The grounding wire ensures that a current is always flowing to the ground, preventing any dangerous electrical shorts that could otherwise cause injuries or property damage.
THHN is also a great option for outdoor and wet environments. This is because it’s designed to be impervious to moisture and other environmental factors that could degrade the wire’s insulation over time. Many of the THWN wiring options available today are dual-rated and can be safely used in dry locations up to 90 degrees Celsius or wet locations up to 75 degrees Celsius.
When deciding which type of wire to use in a given context, it’s important for electricians and construction managers to understand the strengths and weaknesses of each option. Choosing the right wire for an application can save money and prevent costly repairs down the road. To ensure that the wire is rated appropriately for a specific task, it’s important to follow the NEC guidelines for appropriate cable sizes and insulator thicknesses. Also, be sure to choose a NEC-approved wire that is appropriate for the temperature range of the environment where it will be installed.
Type EMT Wiring
EMT electrical conduit is a common choice for commercial wiring projects because it’s lightweight and easy to handle. It’s also less expensive than galvanized rigid conduit (GRC).
EMT is an unthreaded, thin-wall metal tubing that’s typically made of coated steel. It can be used to protect and route wiring in residential, commercial, and industrial buildings. This type of conduit is 40% lighter than GRC and is generally used to run circuits that don’t require a lot of protection.
To ensure a safe and reliable installation, electricians must pay close attention to the types of fittings they use with EMT. This includes using UL-listed and CSA-certified couplings and connectors. Also, all joints must be tight and properly bonded. Finally, a bending technique must be used that’s appropriate for the size and diameter of each conduit.
Commercial wiring applications typically have increased power demands, so the electrical components must be protected from heat and moisture. One way to do this is by running the wires through a conduit, which provides an extra layer of insulation. Another option is to place the wires in a trough that runs along a framing member or over joists in a ceiling.
Before beginning an electrical conduit installation, it’s important to survey the battlefield. This step helps electricians plan the most effective route for the conduit and spot potential challenges that could affect its performance. It’s also a good idea to check local codes and regulations before beginning the job.
After scouting the site, it’s time to choose the right EMT fittings and accessories. Locknuts and conduit reamers are essential for ensuring a secure fit. Adding bushings to the ends of each conduit helps prevent wires from being nicked or damaged by sharp edges. In addition, some EMT comes with corrosion-resistant coatings to extend its lifespan in harsh environments.
Once the conduit is ready for use, it should be fastened to walls, floors, or ceilings with straps or hangers. It’s also important to adhere to support spacing requirements, as specified by the National Electrical Code. Failure to do this can lead to a fire hazard or non-compliance with safety standards.