An electrical room is a 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 switchboard An electric switchboard is a device that distributes electricity from one or more sources of supply to several smaller load circuits. It is an assembly of one or more panels, each of which contains switching devices for the protection and contro ...

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Distribution board A distribution board (also known as panelboard, breaker panel, electric panel, DB board or DB box) is a component of an electricity supply system that divides an electrical power feed into subsidiary circuits while providing a protective fuse ...

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Circuit breaker A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by an overcurrent or short circuit. Its basic function is to interrupt current flow to protect equipment and to prevent the risk ...

s and disconnects *

Motor control center A motor control center (MCC) is an assembly to control some or all electric motors in a central location. It consists of multiple enclosed sections having a common power bus and with each section containing a combination starter, which in turn con ...

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

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Busbar In electric power distribution, a busbar (also bus bar) is a metallic strip or bar, typically housed inside switchgear, panel boards, and busway enclosures for local high current power distribution. They are also used to connect high volt ...

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Electricity meter North American domestic analog electricity meter. Electricity meter with transparent plastic case (Israel) North American domestic electronic electricity meter An electricity meter, electric meter, electrical meter, energy meter, or kilowa ...

s * Backup batteries in a

Battery room A battery room is a room that houses batteries for backup or uninterruptible power systems. The rooms are found in telecommunication central offices, and provide standby power for computing equipment in datacenters. Batteries provide direct cu ...

Fire alarm control panel A fire alarm control panel (FACP), fire alarm control unit (FACU), fire indicator panel (FIP), or simply fire alarm panel is the controlling component of a fire alarm system. The panel receives information from devices designed to detect and re ...

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Distribution frame Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

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

electrical substation A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions. Between the generating station and ...

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 syst ...

system or

busbar In electric power distribution, a busbar (also bus bar) is a metallic strip or bar, typically housed inside switchgear, panel boards, and busway enclosures for local high current power distribution. They are also used to connect high volt ...

s. 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 Fire detectors sense one or more of the products or phenomena resulting from fire, such as smoke, heat, infrared and/or ultraviolet light radiation, or gas. In dwellings, smoke detectors are often stand-alone devices. In non-domestic buildings, fir ...

and

fire suppression system Fire suppression systems are used to extinguish, control, or in some cases, entirely prevent fires from spreading or occurring. Fire suppression systems have an incredibly large variety of applications, and as such, there are many different types ...

s, such as

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

, may be installed. A large electrical room may have extensive provisions for grounding (earthing) and bonding enclosures of electrical equipment to prevent

stray voltage Stray voltage is the occurrence of electrical potential between two objects that ideally should not have any voltage difference between them. Small voltages often exist between two grounded objects in separate locations, due to normal current flo ...

and danger of electric shock, even during faults in the electrical system.

Lightning protection A lightning rod or lightning conductor (British English) is a metal rod mounted on a structure and intended to protect the structure from a lightning strike. If lightning hits the structure, it will preferentially strike the rod and be conducte ...

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 blocking the electromagnetic field (EMF) in a space with barriers made of conductive or magnetic materials. It is typically applied to enclosures, for isolating ...

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

access control In the fields of physical security and information security, access control (AC) is the selective restriction of access to a place or other resource, while access management describes the process. 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 constructed objects such as buildings and non-building structures. Buildings must conform to the code to obtain planning permission ...

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 terminal Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure. Wiring is subject to safety standards for design and installation. Allowable ...

s. 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. 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