An electric enclosure refers to a cabinet that encloses numerous electronic and electrical components. It serves two uses- protection of the user from electric shock and safeguarding parts covered from external damage.

Electrical enclosures have been designed to be both functional as well as attractive. They may also be required to exhibit favourable properties as regards power dissipation, electrical breakdown, and electromagnetic interference.

The cabinet of electrical enclosures helps to mount displays, knobs, and switches. It protects components from the vagaries of the environment. It is designed keeping in mind both utility and aesthetic value. The features and performance of enclosures for electrical equipment in hazardous areas like coal mines may be subject to regulations. Electronic packaging may impose several demands on enclosures for protection from electrostatic discharge, interference from radiofrequency, and heat dissipation.

Different national regulatory standards govern the needs of electrical cabinets and enclosures. Stringent regulations apply to those used in hazardous areas facing explosion or fire risks, especially applicable to locations like chemical plants where there are potential risks like combustible dust, flammable gases, and other volatile vapours. Special kinds of electrical enclosures apply to areas prone to floods or lightning strikes.

An electrical enclosure gives protection to electrical equipment like transformers, power generators, and different telecommunication devices. They are available in various sizes, though broadly, those used for industrial applications are bigger than those used in residential areas.

The market can be divided into two groups: enclosures used in distribution & transmission and those used in power generation. This market can also be divided by the kind of material used to manufacture the enclosure like plastics, metals, and metal alloys.

Electrical enclosures are set up in a wide variety of locations: outdoors, in heavy rain, high levels of humidity, solar radiation, and exposure to corrosive agents like dust and sea salt. Other factors include threats of sabotage and vandalism. Following are the main kinds of enclosure material:

  • Polycarbonate

Such enclosures have several advantages over metallic options, especially their resistance to acidic and corrosive environments. Surprisingly, plastics like these have good impact resistance and do not scratch or dent easily. Their non-conductive nature gets rid of the requirement for earth bonding. They are used mostly for small enclosures like local control stations.

  • Mild Steel

Steel has always been a common material because of its relative strength and cost-effectiveness. It is almost 25 times stronger than plastic. But the bad news is that steel is highly vulnerable to corrosion. It must be coated using materials like painting, powder coating, zinc coating, or galvanizing. Such enclosures are used for several purposes ranging from road traffic control equipment to indoor switchboards. They are ideal for outdoor uses except for corrosive environments like coastal areas. But care must be taken as regards electric shock because steel is conductive.

  • Aluminium

It is susceptible to corrosion like steel but builds up a protective layer of aluminium oxide on contact with oxygen, which prevents further corrosion. Highly useful in outdoor areas but is painted or powder-coated for good looks.

It is lighter in weight but not as hard or as strong as steel. Hence, thicker sheets are utilized. Another benefit of Aluminium is that it lacks magnetic qualities, getting rid of the eddy-currents inside the enclosure. This is why there is a common usage of aluminium gland plates. Suitable applications include outdoor switchboards in coastal areas.

  • Stainless Steel

This is a steel alloy that contains a quantity of Nickel and Chromium, which makes it highly impervious to staining and corrosion. There exist several grades of stainless steel. The most common are 304 (containing 8% Nickel and 18% chromium) and 316 (2% Molybdenum, 10% nickel and 16% Chromium).

Stainless steel is hard than mild steel. It is tough to work with like cutting but is structurally stronger. Because of the quality of high resistance to corrosion, it is possible and common for use in the uncoated form, even in locations that are outdoors. For aesthetic considerations, uncoated stainless steel is often polished. Such uncoated stainless steel is highly popular in the food industry as it can be easily washed over without risk of building up bacteria and grime.

Because of its content of more expensive metals, stainless steel is three times more costly than mild steel. Ideal applications include areas for food preparation, corrosive environments, and coastal areas.

These are some interesting facts about electrical cabinets and enclosures.