An electrical room is a technical room or space in a building dedicated to electrical equipment. Its size is usually proportional to the size of the building; large buildings may have a main electrical room and subsidiary electrical rooms. Electrical equipment may be for power distribution equipment, or for communications equipment.Albert Thumann, Harry Franz, ''Efficient Electrical System Design Handbook'', Fiarmont Press 2009 pages 76-77 Electrical rooms typically house the following equipment: * Electric switchboards * Distribution boards *

Circuit breaker A circuit breaker is an electrical safety device designed to protect an Electrical network, electrical circuit from damage caused by current in excess of that which the equipment can safely carry (overcurrent). Its basic function is to interr ...

s and disconnects * Motor control centers *

Transformer In electrical engineering, a transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple Electrical network, circuits. A varying current in any coil of the transformer produces ...

s * Busbars *

Electricity meter file:Hydro quebec meter.JPG, North American domestic analog signal, analog (Galileo Ferraris, Ferraris disk) electricity meter. file:Transparent Electricity Meter found in Israel.JPG, Electricity meter with transparent plastic case (Israel) fil ...

s * Backup batteries in a Battery room * Fire alarm control panels *

Distribution frame In telecommunications, a distribution frame is a passive device which terminates cables, allowing arbitrary interconnections to be made. For example, the Main Distribution Frame (MDF) located at a telephone exchange, telephone central office te ...

s In large building complexes, the primary electrical room may house an indoor electrical substation.

Construction features

The construction features of an electrical room vary depending on the scope of the equipment to be installed. Floors may be reinforced to support heavy transformers and switchgear. Walls and ceilings may have to support a heavy

cable tray In the electrical wiring of buildings, a cable tray system is used to support insulated electrical cables used for power distribution, control, and communication. Cable trays are used as an alternative to open wiring or electrical conduit system ...

system or busbars. Additional ventilation or air conditioning may be needed, since electrical apparatus gives off heat but the temperature must not rise beyond the tolerance of equipment. Double doors may be installed to allow for maintenance of large equipment. If utility service entrance equipment and metering is present in the room, special provisions may be made for access by utility personnel. Fire detection and fire suppression systems, such as

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

, may be installed. A large electrical room may have extensive provisions for grounding (earthing) and bonding enclosures of electrical equipment to prevent stray voltage and danger of electric shock, even during faults in the electrical system. Lightning protection requires different measures than protection from power-frequency faults. Electrical rooms may have

electromagnetic shielding In electrical engineering, electromagnetic shielding is the practice of reducing or redirecting the electromagnetic field (EMF) in a space with barriers made of conductive or magnetic materials. It is typically applied to enclosures, for isol ...

to prevent interference to nearby sensitive audio or video equipment. In large facilities

access control In physical security and information security, access control (AC) is the action of deciding whether a subject should be granted or denied access to an object (for example, a place or a resource). The act of ''accessing'' may mean consuming ...

systems may control admission to the room.

Regulations

Layout details and construction of electrical rooms will be controlled by local

building code A building code (also building control or building regulations) is a set of rules that specify the standards for construction objects such as buildings and non-building structures. Buildings must conform to the code to obtain planning permis ...

and electrical code regulations. Requirements for an electrical room relate to fire safety and electrical hazards. An electrical room is usually required to be secured from access by unauthorized persons; these rules are especially strict where equipment within the room has exposed live terminals. Regulations may require two separate means of exit from a room where the power rating of circuits exceeds some threshold, to allow for quick exit in an emergency.Truman C. Surbrook, Jonathan R. Althouse, ''Interpreting The National Electrical Code 7E'' Cengage Learning, 2004 , page 34 Rooms containing oil-filled equipment may be required to have fire-resistant construction or active fire suppression equipment in the room and may be designated as an ''electrical vault''. Since power distribution often requires large numbers of electrical cables, special measures for fire resistance of cables and cable trays may be also specified by regulations. In industrial buildings that handle flammable gases or liquids, or combustible dusts, special electrical rooms may be prepared that have ventilation and other measures to prevent an explosion hazard that would otherwise exist with

electrical equipment in hazardous areas In electrical engineering, electrical and safety engineering, safety engineering, hazardous locations (HazLoc, pronounced ''haz·lōk'') are places where fire or explosion hazards may exist. Sources of such hazards include gases, vapors, dust e ...

. For large installations, it may be less costly overall to use a special room than to install a large number of devices that are resistant to the hazardous conditions. Similarly, in wet or corrosive environments, electrical equipment may be separated in a room that can be protected from the atmospheric conditions. Building code and electrical code regulations will dictate minimal working space around equipment to allow safe access during maintenance. Practical design of an electrical room will consider layout of the initial equipment and allow for additions over the economic life of the facility.

References

{{DEFAULTSORT:Electrical Room Rooms Electric power distribution

Construction features

Regulations

See also

References