science

Electrical enclosure

Electrical enclosure is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Electrical enclosure rather than just read about it. In short: An electrical enclosure, power box (US), or feeder pillar (UK), is a cabinet for electrical or electronic equipment to mount switches, knobs and displays and to prevent electrical shock to equipment users and protect the contents from the environment. The enclosure is the only part of the equipment which is seen by users.

Key takeaways

Electrical enclosure belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Electrical enclosure to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Electrical enclosure from memory before moving on to harder problems.

Reference excerpt

An electrical enclosure, power box (US), or feeder pillar (UK), is a cabinet for electrical or electronic equipment to mount switches, knobs and displays and to prevent electrical shock to equipment users and protect the contents from the environment. The enclosure is the only part of the equipment which is seen by users. It may be designed not only for its utilitarian requirements, but also to be pleasing to the eye. Regulations may dictate the features and performance of enclosures for electrical equipment in hazardous areas, such as petrochemical plants or coal mines. Electronic packaging may place many demands on an enclosure for heat dissipation, radio frequency interference and electrostatic discharge protection, as well as functional, esthetic, and commercial constraints.

Standards Internationally, IEC 60529 classifies the IP Codes (ingress protection rating) of enclosures. In the United States, the National Electrical Manufacturers Association (NEMA) publishes NEMA enclosure type standards for the performance of various classes of electrical enclosures. The NEMA standards cover corrosion resistance, ability to protect from rain and submersion, etc.

Materials Electrical enclosures are usually made from rigid plastics, or metals such as steel, stainless steel, or aluminum. Steel cabinets may be painted or galvanized. Mass-produced equipment will generally have a customized enclosure, but standardized enclosures are made for custom-built or small production runs of equipment. For plastic enclosures ABS is used for indoor applications not in harsh environments. Polycarbonate, glass-reinforced, and fiberglass boxes are used where stronger cabinets are required, and may additionally have a gasket to exclude dust and moisture. Metal cabinets may meet the conductivity requirements for electrical safety bonding and shielding of enclosed equipment from electromagnetic interference. Non-metallic enclosures may require additional installation steps to ensure metallic conduit systems are properly bonded.

Stainless steel and carbon steel Carbon steel and stainless steel are both used for enclosure construction due to their high durability and corrosion resistance. These materials are also moisture resistant and chemical resistant. They are the strongest of the construction options. Carbon steel can be hot or cold rolled. Hot rolled carbon steel is used for stamping and moderate forming applications. Cold rolled sheet is produced from low carbon steel and then cold reduced to a certain thickness and can meet ASTM A366 and ASTM A611 requirements. Stainless steel enclosures are suited for medical, pharma, and food industry applications since they are bacterial and fungal resistant due to their non-porous quality. Stainless steel enclosures may be specified to permit wash-down cleaning in, for example, food manufacturing areas.

Aluminum Aluminum is chosen because of its light weight, relative strength, low cost, and corrosion resistance. It performs well in harsh environments and it is sturdy, capable of withstanding high impact with a high malleable strength.

Polycarbonate Polycarbonate used for electrical enclosures is strong but light, non-conductive and non-magnetic. It is also resistant to corrosion and some acidic environments; however, it is sensitive to abrasive cleaners. Polycarbonate is the easiest material to modify.

Fiberglass Fiberglass enclosures resist chemicals in corrosive applications. The material can be used over all indoor and outdoor temperature ranges. Fiberglass can be installed in environments that are constantly wet.

Terminology Enclosures for some purposes have partially punched openings (knock-outs) which can be removed to accommodate cables, connectors, or conduits. Where they are small and primarily intended to conceal electrical junctions from sight, or protect them from tampering, they are also known as junction boxes, street cabinets or technically as serving area interface.

Telecommunications Telecommunication enclosures are fully assembled or modular field-assembled transportable structures capable of housing an electronic communications system. These enclosures provide a controlled internal environment for the communications equipment and occasional craftspeople. The enclosures are designed with locks, security, and alarms to discourage access by unauthorized persons. Enclosures can be provided with a decorative facade to comply with local building requirements.

Fire risk

Electrical enclosures are prone to fires that can be very intense (in the order of the megawatt) and are hence an important topic of fire safety engineering.

See also 19 inch rack Cable management DIN rail Housing (engineering) Rack unit Telco can Utility box art Utility vault

References

External links IP Protection Ratings vs. NEMA Equivalency What Is an Electrical Enclosure? Definition, Using, Requirements

Illustrations

Worked examples

Example 1 — a first encounter with Electrical enclosure

Start with the simplest possible case. Write down what Electrical enclosure claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Electrical enclosure before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Electrical enclosure ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Electrical enclosure

In research: Electrical enclosure appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Electrical enclosure in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Electrical enclosure is common in secondary-school and first-year university syllabi. It links to neighbouring topics Electrical enclosures, so understanding it makes those chapters shorter.
In everyday life: Look for Electrical enclosure outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Electrical enclosure in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Electrical enclosure means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Electrical enclosure out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Electrical enclosure in simple terms?

Why does Electrical enclosure matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Electrical enclosure?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Electrical enclosure.