Commercial Electrical Service focuses on installing power distribution systems, electrical panels, wiring, and power receptacles. It also includes determining the best solution for lighting design, emergency systems, data wiring, and HVAC integration.
Commercial electrical services must follow specific processes and safety regulations. Understanding the different types of conductors and busways can help ensure proper installation.
MC cable, also known as metal-clad cable, is a type of commercial electrical wiring used in industrial settings. This wiring method offers durable protection and a robust electrical performance, making it ideal for demanding environments. However, the choice between MC and conduit systems hinges on an installation’s specific environmental needs and adherence to local electrical codes.
The primary difference between MC and conduit systems is that MC cables use an aluminum interlocking armor to protect the conductors, while conduit uses an outer sheath made of PVC, steel, or aluminum for this purpose. This additional layer of protection provides greater durability and reliability for installations in harsh or hazardous environments, including factories and theaters.
In addition to the protective metal sheath, MC cables feature insulation materials like cross-linked polyethylene (XLPE) and thermoplastic that guard against electrical shorts, fire hazards, and excessive heat. They can maintain circuit functionality for up to two hours in the event of a fire, allowing critical systems to continue working.
Before installing MC cable, electricians must first determine the length of run needed for the project. This will allow them to choose the appropriate size of MC cable connector and ensure that the installer can terminate all of the wires without compressing the aluminum sheath. The installer must then support the MC cable at intervals specified by the National Electric Code, typically every 6 feet for horizontal runs and within 12 inches of each termination point. Supports can include straps, clamps, or hangers. The installer can then flex the MC cable with a conduit bender or carefully hand-bend it to avoid sharp bends that exceed the minimum bend radius.
Once the MC cable is supported, it can be pulled through junction boxes and devices. To prepare for this, the installer must strip the end of the cable armor back to expose the insulated conductors. This can be done by cutting a ring around the cable with an armored cable cutter or by using a rotary cutter, being careful not to cut too deeply. A specialized MC cable connector is then placed over the conductors, and the armor and conductors are then taped together.
Type EMT Wiring
Electrical metal tubing, or EMT, is a popular option for commercial electrical wiring projects. Its lightweight design makes it easy to handle and install, while its galvanized steel construction protects wiring from corrosion. In addition to its versatility, EMT is cost-effective and offers similar protection as rigid metal conduit (RMC).
EMT is an excellent choice for a wide variety of electrical applications, including buried or concrete-encased runs in outdoor environments. It can also be used in wet locations as long as it is installed with proper water-resistant seals, such as compression couplings.
Compared to RMC, EMT is more affordable and easier to install. It can be cut to length with a hacksaw or pipe cutter and bent using a standard conduit bender, allowing it to navigate corners and other obstacles. When bending EMT, it is important to not deform the tube or create sharp angles that could damage wire insulation. To prevent this, it is recommended to use a conduit reamer after cutting or bending.
EMT can be color-coded with paints and coatings to identify different power systems in a facility, or to coordinate with architectural designs. It is also available in non-magnetic versions, which are suitable for installations that require electromagnetic interference shielding.
The type of conduit system you choose for your commercial electrical service is a crucial decision that impacts safety, compliance, and operational efficiency. To make the best decision, you should always consult a licensed electrician. They will be able to provide expert guidance and installation services aligned with your business’s specific needs.
Regular inspections are essential for ensuring the integrity of any electrical conduit system. Identifying and addressing any issues early on ensures the longevity of the system and helps maintain compliance with industry standards. Whether it’s corrosion, physical damage, or loose fittings, early intervention can avoid costly repairs down the road.
Type MC/EMT Wiring
This type of wiring is very common in commercial buildings and properties. It is a flexible alternative to conduit systems and is ideal for situations with limited space or insensitive areas. It is a very reliable solution for commercial electrical wiring, and it can support higher voltage levels than Type NM or Romex. However, it is important to note that this option will not be appropriate for all locations and should always be compared against other wiring solutions in order to determine whether it is the right fit.
MC cable looks similar to the old BX cables and is available with either a smooth or corrugated metal sheath and can contain copper or aluminum conductors. It also has an equipment grounding conductor and is usually insulated in order to reduce the risk of electric shock. In addition, it is capable of carrying high amounts of current and can withstand a variety of temperatures and environmental conditions.
The insulating material that covers MC cables protects them from various external elements. It provides resistance to chemicals, heat, moisture, and corrosion, making them suitable for use in various applications. It also protects the conductors from physical abuse and limits the risk of fire due to overheating. It also offers resistance to abrasion and impact, making it an ideal choice for applications that require a rugged cable that can handle rough handling.
When working with MC cables, it is important to ensure that they are properly prepared for termination. This includes stripping the sheathing and checking for damage. It is also important to verify that the conductors can carry the amount of current that they are intended for. This can be done by using a voltage drop calculator to determine the appropriate size of wire for the application.
EMT is often installed in conjunction with MC cables. It can be bent in the field to form elbows and other bends that are not possible with rigid conduit. It is usually used in trade sizes 1/2’’ through 1-1/4’’, and bending is accomplished with a hand bender, hydraulic bender, or an electric power bender. The process is easier than forming the bends in rigid conduit, and it can be done quickly by an experienced installer. It is important to wear safety glasses and follow all bending guidelines.
Type MC/SM Wiring
When it comes to residential and commercial electrical wiring, MC cable is an excellent choice that provides superior construction and functionality. It features conductors encased in a metal sheath, making it resistant to moisture and other environmental factors that can cause damage or short circuits. MC cables also feature an equipment grounding conductor that helps to avoid interference from electromagnetic forces.
These conductors can be made of copper or aluminum, though most applications require copper armored options due to their corrosion resistance and superior electrical properties. The sheaths of MC cables can be constructed from either steel or aluminum, and they may be smooth or corrugated. The sheath is usually bonded to the conductors through an insulated layer of THHN-type insulation.
The insulating layers of MC cables protect the metal sheath and the conductors within, helping to mitigate the risk of accidental contact. In addition, the insulated sheaths help to manage temperature, which can reduce the risk of fire and other forms of mechanical destruction.
As a result, this type of cable is ideal for use in both indoor and outdoor settings, including corrosive environments. It is often used to wire swimming pools and spas, as well as docks, marinas, and greenhouses. It can also be used in a variety of industrial and commercial settings, including hospitals and other healthcare facilities.
One of the most significant benefits of MC cables is their ease of installation. They can be installed without the need for a separate conduit system, which can save time and money on labor costs. In addition, they can be installed in direct burial situations and withstand wet conditions.
Ensure that MC cables are embedded at the correct depth level, as per the prevailing electrical codes and safety standards. Additionally, they should be properly grounded to prevent electrical faults, such as fire or electric shock, which are common in these types of installations. By following these guidelines, electricians can guarantee the safety and reliability of MC cables for their clients. They can also help ensure that the cables are protected against environmental factors by using suitable waterproofing materials and sealants, such as PVC or CPVC, for example.