Personnel are protected from accidental contact with live electrical equipment by the enclosure. It also protects the enclosed equipment from certain environmental conditions. Safety switches can be made up of a single switch or a combination of switches and fuses. A single switch only controls power to one circuit while a combination switch/fuse controls several circuits. Switches and fuses must be installed and wired according to local codes.
Safety switches are used to cut off power to a section of cable when the cable is being worked on by maintenance personnel. They provide additional protection for workers by shutting off power before they start work on a section of cable. Safety switches should be placed in remote locations away from working areas so that they can't be accidentally activated.
Safety switches come in two main types: magnetic and electronic. Magnetic safety switches use a magnet to control power to a section of cable. These magnets can be attached to doors, hatches, or panels to shut off power when they are opened. Electronic safety switches use sensors to detect dangerous conditions inside an enclosure and then shut off power. For example, an electronic switch may sense that there is heat inside the enclosure that could lead to a fire, so it will shut off power until such time as the situation has been corrected.
Magnetic safety switches are commonly used on industrial machinery because they don't require electricity to operate them.
Electrical enclosures are intended to protect equipment users from electrical shock and to protect the contents from the environment. Carbon steel, stainless steel, fiberglass, and polycarbonate may all be used to make electrical enclosures. The materials are chosen based on their resistance to corrosion or oxidation, as well as their strength and other characteristics desired for the enclosure.
Carbon steel is a common material for electrical conduit because it's affordable and easy to work with. However, carbon steel will rust if it isn't protected from exposure to air and water. To prevent this, manufacturers coat carbon steel conduit with teak oil or epoxy before installing it in the field.
Stainless steel is a more resistant option than carbon steel for outdoor use because it won't rust. However, unlike carbon steel, stainless steel cannot be cut with a knife and must be drilled and tapped instead. This makes working with it difficult and expensive when you need to replace an existing enclosure with one that is identical to the old one.
Fiberglass is another common material used for electrical conduit because it's lightweight, flexible, and resists corrosion. Fiberglass can be molded into virtually any shape and sized hole can be drilled through it without damaging the surrounding area. It's also non-conductive which prevents accidental contact with live power lines.
According to the National Electrical Manufacturers Association (NEMA), an enclosure is a surrounding casing designed to prevent workers from inadvertent contact with enclosed equipment while also protecting the enclosed equipment from specified environmental conditions. The term covers many different types of enclosures, including metal and plastic cases. Enclosures are used to protect people or property from electrical shock or damage from malfunctioning equipment.
The function of an enclosure is to contain electrical components in a safe environment. This containment may be for the protection of people who might be injured by an electric shock or exposed to harmful materials. It may also be to protect property from damage caused by malfunctioning equipment. Finally, an enclosure may simply serve to provide an aesthetic appeal to an electrical system.
An electrical panel is the distribution center for electricity from a utility company into individual houses for use by lighting, heaters, air conditioners, and other appliances. The meter installed on each street side of a house measures how much electricity you use, which determines your bill. It may be located on the sidewalk in front of your house, attached to the curb, or inside the house next to the breaker box. This article focuses on meters located outside a house; if you have a question about what happens to your meter when you move out, see our article on "How do I report an empty house?."