A reference number used by the European Communities to identify dangerous substances, in particular those registered under EINECS. Source: United Nations GHS
Glossary - E
This is a glossary of older terms. While many of the definitions are unchanged, some of the definitions may be out of date and some of the terms may no longer be in use in the Data Center industry. This legacy glossary provides definitions for hundreds of information and communications technology (ICT) and data center terms and acronyms. Arranged alphabetically and searchable, the glossary explains common industry vocabulary.
EC Number or (ECN)
EC-class
Equipment cooling class
ECM
Electronically commutated motor
Economizer, Air
A ducting arrangement and automatic control system that allow a cooling supply fan system to supply outdoor (outside) air to reduce or eliminate the need for mechanical refrigeration during mild or cold weather
Economizer, Water
A system by which the supply air of a cooling system is cooled directly or indirectly or both by evaporation of water or by other appropriate fluid (in order to reduce or eliminate the need for mechanical refrigeration)
Edge Data Center
Edge data center. Source: PwC
Edge Equipment
See communication equipment
EER
Energy efficiency ratio
Efficiency
The ratio of the output to the input of any system. Typically used in relation to energy. Smaller amounts of wasted energy denote high efficiencies
Efficiency, HVAC System
The ratio of the useful energy output (at the point of use) to the energy input in consistent units for a designated time period expressed in percent
EINECS
European Inventory of Existing Commercial Chemical Substances. Source: United Nations GHS
ELC
Electrical Loss Component per ANSI / ASHRAE Standard 90.4 – 2016. The design ELC is the combined losses of three segments of the electrical chain: incoming electrical service segment, UPS segment, and ITE distribution segment. Source: ASHRAE
Electrical Bus
See bus, power
Electrolyte
A substance that dissociates free ions when dissolved (or molten) to produce an electrically conductive medium
Electrolyte, Absorbed
Valve regulated lead-acid (VRLA) cells of this design are constructed with a controlled volume of liquid electrolyte contained in a highly absorbent, blotter-like separator positioned between closely spaced plates. This non-woven separator distributes the electrolyte uniformly and maintains it in contact with the plate active material, while permitting the passage of oxygen evolved during charging. Cells with absorbed electrolyte technology have inherently low internal resistance and can be designed to provide a very high-rate, short-duration current. Cells with absorbed electrolyte are also known as absorbed glass mat (AGM) types
Electrolyte, Gelled
Valve regulated lead-acid (VRLA) cells of this design are similar to vented designs, except that the electrolyte has been "gelled" to immobilize it. They can provide a high-rate, short-duration current, but because of the higher internal resistance, they are not as effective as the absorbed electrolyte design. However, the higher thermal conductivity in gelled designs makes them better suited for elevated temperature applications than equivalent absorbed electrolyte cells. A gelled electrolyte cell is typically heavier and larger than an absorbed electrolyte cell for a given capacity
Electromagnetic Compatibility (EMC)
The ability of electronic equipment or systems to operate in their intended operational environments without causing or suffering unacceptable degradation because of electromagnetic radiation or response
Electronically Commutated Motor (EC)
EC motor is widely used for fans and pumps to reduce the drive energy consumption. Source: Schneider Electric
Electronically Commutated Motor (ECM)
An EC motor is a DC motor with a shunt characteristic. The rotary motion of the motor is achieved by supplying the power via a switching device, the so-called commutator. On the EC motors, this commutation is performed using brushless electronic semiconductor modules
Electronics, Air- and Liquid-cooled
Electronic equipment that uses both air and liquid
Electronics, Air-cooled
Electronic equipment that is directly cooled by air
Electronics, Liquid-cooled
Electronic equipment that is directly cooled by liquid
Electrostatic Discharge (ESD)
The sudden flow of electricity between two objects at different voltage potentials. ESD is a primary cause of integrated circuit damage or failure
EMI
Electromagnetic interference
End Station
A system attached to a LAN that is an initial source or a final destination of MAC frames transmitted across that LAN. A network layer router is, fro the perspective of the LAN, an end station. A MAC bridge, in its role of forwarding MAC frames from one LAN to another, is not an end station (see IEEE 802.3, Clause 43)
Energy
The ability to do work or the ability to move an object. Electrical energy is usually measured in kilowatt-hours (kWh), while heat energy is usually measured in British thermal units (Btu).power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines. Source: Oxford Languages
Energy Efficiency
Energy efficiency can be defined for a component or service as the amount of energy required in the production of that component or service; for example, the amount of steel that can be produced with one billion Btu of energy. Energy efficiency is improved when a given level of service is provided with reduced amounts of energy inputs, or services or products are increased for a given amount of energy input. Source: United States Office of Energy Efficiency and Renewable Energy (EERE)
Energy Efficiency Ratio (EER)
The ratio of net equipment cooling capacity in BTU/h to total rate of electric input in watts under designated operating conditions. When consistent units are used, this ratio becomes equal to COP (see also coefficient of performance)
Enterprise Data Center
Data center which your organization owns/operates, hosting only your organization’s workloads. Source: Uptime Institute
Enthalpy (Total Heat)
See heat, total
EPDM
Ethylene Propylene Diene Monomer: a type of synthetic rubber. Source: OCP
Equipment
Refers to, but not limited to, servers, storage products, workstations, personal computers, and transportable computers. May also be referred to as electronic equipment or IT equipment
Equipment Air
See air, equipment
Equipment Recommended Operation Range
Manufacturer's specifications generally reference a range in which a piece of equipment CAN function. A recommended range refers to the range at which equipment is the most efficient and realizes the least amount of wear and tear, extending its useful life
Equipment Room
Data center or telecommunications central office room that houses computer and/or telecommunications equipment. For rooms housing mostly telcommuncations equipment, see telcordia GR-3028-CORE
Equipment, Air cooled
Equipment conditioned by removal of heat using air
Equipment, Liquid cooled
Equipment coniditioned by the removal of heat using a liquid
ESD
Electro-static discharge. Source: ASHRAE
ESG
Environmental, social, and governance criteria are a set of standards for a company’s behavior used by socially conscious investors to screen potential investments. Environmental criteria consider how a company safeguards the environment, including corporate policies addressing climate change, for example. Social criteria examine how it manages relationships with employees, suppliers, customers, and the communities where it operates. Governance deals with a company’s leadership, executive pay, audits, internal controls, and shareholder rights. Source: ASHRAE or an alternate definition of A set of standards that guides companies to operate responsibly, deliver sustainable outcomes and provide meaningful benefits to a broad range of stakeholders. Source: PwC
Ethernet
A networking system that enables high-speed data communication over coaxial cables
ETSI
European Telecommunications Standards Institute
EU
European Union. Source: United Nations GHS
Evaporative Condenser
Condenser in which the removal of heat from the refrigerant is achieved by the evaporation of water from the exterior of the condensing surface induced by the forced circulation of air and sensible cooling by the air
Exchanger, Rotary Heat
A heat exchanger in which the heat exchange surface rotates
Executable
As an adjective, executable means that the described item can be executed. In computer talk, executable has been also used as a noun, where it means an executable program, or in other words, something that is ready to run without further modification. Commonly, the term executable is used to refer to the binary file that is the final result of compiling source code