From the very beginning of electrical power usage, switches were know as cut-outs. The name comes from the use of “cut out” the power. A simple term but effective in its meaning, the cut out was simplified switch made from copper bars and insulated “T” handle for the user to switch on and off. Enclosures are where the cut-outs are installed and later placed in boxes. Enclosures are that physical part that protected users from electrical currents and their safety.
When electricity was brought into every home, in the days before enclosures existed as knife-switch cut out with cartridge and edison-base fuses, people quickly gained the knowledge that getting too close to the electrical service was scary and unpleasant. It could be very deadly. For that reason, to improve safety, they started installing live parts in wood cabinets. This way, the term “cabinet” was intended and still in use till today. The cabinet was similar looking like your everyday kitchen cabinet and made from dry wood materials. It was a great improvement compared to how it used to be before, but when different manners of utilization were discovered for electricity, they lead to fire hazard and electrical shocks. That’s why metal cabinets were invented and were more fire resistant.
Enclosures and cases often contain over current devices, that are there to protects the device. Not only over current devices, they also contain conductors and other equipment such as timers, relays and much more. Electrical substation or switchyards is always surrounding the electrical equipment as a fence or a wall that encloses transformers, switches, reactors, etc.
The primary function of enclosures is to enclose electrical conductors and equipment. They provide guidance for selection of enclosures for specific outdoor or indoor locations that are standar for EMA types. Continue reading