What cable is suitable for dry locations only?

What cable is suitable for dry locations only?

The NEC only permits the use of type AC cable in dry environments. Interlocked Type MC cable must have a corrosion resistant jacket and wet location rated conductors to comply with the NEC for usage in wet situations.

Is MC cable weatherproof?

Is MC cable weather resistant? MC may be used outside, wet (if the conductors are rated for it), and immediately underground (if cable is so rated). It should be noted that even if MC cable is exposed to these conditions, it does not mean that it will last forever. As with any cable, damage such as cuts, breaks, or defects in insulation can cause electrical failure. The cable itself is not damaged until it reaches its end of life, at which time it will have to be replaced.

MC cable is designed to handle severe outdoor conditions including heat, cold, rain, snow, and wind. The metal shield provides additional protection for the insulated conductor within. The outer covering material must be flexible enough to allow for installation changes/curls, but still provide adequate resistance to weathering factors such as moisture, sunlight, temperature changes, etc.

The metal shielding also acts as a ground plane when used with power-ground cables. This allows current to flow through the cable rather than being forced into isolated sections of wire. This is important when working near power lines or other metal objects because you don't want current to be diverted away from its path otherwise damage could occur.

MC cable is commonly used by utility companies to tap into existing wiring systems without having to dig up streets or lawns.

What are the uses permitted by the NEC for metal-clad cable?

The 2017 NEC is the basis for all questions and answers. A code change is indicated by underlined text. Q. What are the NEC's allowed applications for metal-clad cable (Type MC)? A. The Code specifies a wide range of general and particular applications for Type MC cable. Sec. 330.10 (A) and (B) outline them (B). Metal-clad cable is used in wiring methods that require electrical conductivity between components of the wiring system. It is usually covered with a layer of insulation when installed, but this isn't required by the Code. Wiring method categories using Type MC cable include: 360.16(A) armored cable—for use in public buildings where protection from physical attack is necessary 360.17(A) armored cable—for use in hazardous locations such as laboratories and industrial facilities 370.16(A) aluminum cable—for use in public buildings and residential housing where resistance to environmental conditions is important 371.16(A) aluminum cable—for use in commercial building projects where resistance to environmental conditions is important 380.16(A) copper cable—for use in other applications where resistance to environmental conditions is important.

360.16(A) and (4): Armored cable shall be specified by number or letter designation indicating the nominal diameter in inches of the outer protective covering material with or without an inner semiconducting shield.

Which type of cable is allowed in hazardous locations?

Type MC-HL is authorized in hazardous (classified) situations of Class I, Division 1. This is a multi-conductor, gas and vacuum-tight, metal-sheathed continuous corrugated cable with an overall polymeric jacket and an extra equipment grounding conductor scaled in compliance with NEC 250.122. The term "hazardous location" means any room, on any floor of a building or structure, where there is regular access by personnel who may be exposed to electrical shock or other hazards related to working with electricity.

Type MC-HL is used in applications such as sub-station ground cables, power line carriers, distribution centers, industrial buildings, and more. It can carry up to 100 kV or 200 kV with proper design. Type MC-HL has lower weight and size compared to Type MU, which makes it suitable for use in hazardous locations.

Type MC-HL has multiple conductors inside one sheath/conduit: two hot wires (black and white) that carry voltage from terminal lug to terminal lug; a third conductor (red) called neutral that's connected to both terminal lugs; and a fourth conductor (green) called equipment grounding or return current that connects all parts of the system to each other and to some sort of earth ground. Type MC-HL is designed so that if one conductor gets damaged (by being abraded by sand or dirt, for example), the other three remain safe and intact.

Which cable type is permitted to be installed exposed in a plenum space?

MI mineral-insulated cable Because it contains a metal jacket, the Mineral Insulated Type MI cable on the right is allowed in the plenum. It is not permitted to expose a plastic-jacketed MI cable in the plenum. These cables are available in all types of connectors and sizes. For a complete list of which types of cables are permitted in a plenum, see page 3.

CA cable This category includes all copper wire that is not intended to be used as part of a motor vehicle electrical system. It may be aluminum or steel armored cable. This type of cable is usually cut into shorter lengths for installation purposes.

Because these cables are not intended to be used within a motor vehicle electrical system, they are not required to meet the same performance standards as power cables. They also cannot generate heat when current is flowing through them, so they are not restricted in any way regarding temperature.

However, because moisture can cause corrosion to occur with metallic cables, they are not recommended for use in humid environments. If you require cable for use in a plenum environment, then an insulated cable is required.

About Article Author

James Butler

James Butler loves the smell of oil in the air. He's been working in the auto industry for over 30 years and knows all about cars and their parts. James has an eye for detail and can tell what's wrong with a car just by looking at it.

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