1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA EWS 1.3-2016Glossary of Terms Used in the Water SectorNEMA and GEI Consultants, Inc. 1 Glossary of Terms Used in the Water Sector Companion document to Increasing Energy Efficiency in Urban Water Systems: Summary Report Ther
2、e are many ways to express and describe the functions and efficiencies of electrical and hydrodynamic processes. While the electrical efficiency and water efficiency sectors may use the same words or terms when speaking of process and efficiency, these words and terms do not always mean the same thi
3、ng. This glossary was developed to alleviate potential confusion between sectors. For the convenience of the reader, this glossary includes terms used in the definitions of other terms and references used within the above-mentioned companion report. acre-foot A volume of water that covers one acre t
4、o a depth of one foot, or 43,560 cubic feet (1,233.5 cubic meters) or 325,851 gallons. advanced metering infrastructure (AMI) A system that measures, collects, and analyzes energy usage while interacting with advanced devices such as water meters through various communication media, either on demand
5、 or on predefined schedules. This infrastructure includes hardware, software, communications, consumer energy displays and controllers, customer-associated systems, meter data management software, and supplier and network distribution systems. aeration The process of adding air to water. Air can be
6、added to water by either passing air through water or passing water through air through mechanical processes. air blower A device used to ventilate portions of a system such as manholes and lift stations. air lift pump A special type of pump consisting of a vertical riser pipe submerged in the waste
7、water or sludge to be pumped. Compressed air is injected into a tail piece at the bottom of the pipe. Fine air bubbles mix with the wastewater or sludge to form a mixture lighter than the surrounding water, which causes the mixture to rise in the discharge pipe to the outlet. air padding Pumping dry
8、 air (dew point 40F (40C) into a container to assist with the withdrawal of a liquid or to force a liquefied gas such as chlorine or sulfur dioxide out of a container. NEMA and GEI Consultants, Inc. 2 alternating current (AC) An electric current that reverses its direction (positive/negative values)
9、 at regular intervals. altitude valve A valve that automatically shuts off the flow into an elevated tank when the water level in the tank reaches a predetermined level. The valve automatically opens when the pressure in the distribution system drops below the pressure in the tank. analyzer A device
10、 that conducts a periodic or continuous measurement of turbidity or some factor such as chlorine or fluoride concentration. Analyzers operate by any of several methods, including photocells, conductivity, or complex instrumentation. aquifer A natural, underground layer of porous, water-bearing mater
11、ials (e.g., sand, gravel), usually capable of yielding a large amount or supply of water. asset management The process of maintaining the functionality and value of a utilitys assets through repair, rehabilitation, and replacement. Examples of utility assets include buildings, tools, equipment, pipe
12、s, and machinery used to operate a water or wastewater system. The primary goal of asset management is to provide safe, reliable, and cost-effective service to a community over the useful life of a utilitys assets. audit, water A thorough examination of the accuracy of water agency records or accoun
13、ts (volumes of water) and system control equipment. Water managers can use audits to determine their water distribution system efficiency. The overall goal is to identify and verify water and revenue losses in a water system. average demand The average demand for water during a period of time. For e
14、xample, average daily demand is obtained by dividing the total demand for water during a specified period of time by the number of days in that time period. back pressure Pressure that can cause water to backflow into the water supply when a users water system is at a higher pressure than the public
15、 water system. NEMA and GEI Consultants, Inc. 3 backflow A reverse flow condition, created by a difference in water pressures, that causes water to flow back into the distribution pipes of a potable water supply from any source or sources other than an intended source. benchmarking A process an agen
16、cy uses to gather and compare information about the productivity and performance of other similar agencies with its own information. The purpose of benchmarking is to identify best practices, set improvement targets, and measure progress. The benchmark is a standard or point of reference used to jud
17、ge or measure quality or value. best available technology (BAT) BAT is based on the very best (state-of-the-art) control and treatment measures that have been developed, or are capable of being developed, and that are economically achievable within the appropriate industrial category. best practicab
18、le technology (BPT) A level of technology represented by the average of the best existing performance levels within the industrial category. capital improvement plan (CIP) A detailed plan that identifies requirements for the repair, replacement, and rehabilitation of facility infrastructure over an
19、extended period, often 20 years or more. A utility usually prepares or updates this plan annually. For water systems, the CIP is often a part of a master plan that combines water demand projections with supply alternatives and facility requirements. For wastewater systems, the CIP consists of progra
20、ms and projects to upgrade and rehabilitate wastewater collection and treatment systems and increase their capacity to allow for future growth. commissioning The procedure used by a utility agency to inspect, test, train staff, start up, operate, and ultimately accept a new facility. conduit Any art
21、ificial or natural duct, either open or closed, for carrying fluids from one point to another. An electrical conduit, for example, carries electricity. consumptive use The part of withdrawn water that is evaporated, transpired by plants, incorporated into products or crops, consumed by humans or liv
22、estock, or otherwise removed from the immediate water environment. Also referred to as water consumed. NEMA and GEI Consultants, Inc. 4 control system An instrumentation system that senses and controls its own operation on a close, continuous basis in what is called proportional (or modulating) cont
23、rol. controller A device that controls the starting, stopping, or operation of a device or piece of equipment. conveyance loss Water that is lost in transit from a pipe, canal, or ditch by leakage or evaporation. Generally, the water is not available for further use; however, leakage from an irrigat
24、ion ditch, for example, may percolate to a groundwater source and be available for further use. cubic feet per second (cfs) A unit of measurement used to describe rate of flow, in streams and rivers, for example. It is equal to a volume of water one foot high and one foot wide flowing a distance of
25、one foot in one second. One cfs is equal to 7.48 gallons of water flowing each second. For example, if your cars gas tank is two feet by one foot by one foot (two cubic feet), then gas flowing at a rate of one cfs would fill the tank in two seconds. current A movement or flow of electricity. Electri
26、c current is measured by the number of coulombs per second flowing past a certain point in a conductor. A coulomb is equal to about 6.251018 electrons. A flow of one coulomb per second is called one ampere, the unit of the rate of flow of current. cycle A complete alternation of voltage or current i
27、n an AC circuit. debt service The amount of money required annually to pay 1) interest on outstanding debts or 2) funds due on a maturing bonded debt or the redemption of bonds. desalinization The removal of dissolved salts (such as sodium chloride, NaCl) from water by natural means (leaching) or by
28、 specific water treatment processes. direct current (DC) Electric current flowing in one direction only and essentially free from pulsation. distributed control system A computer control system that has multiple microprocessors to distribute the functions performing process control, thereby distribu
29、ting the risk from component failure. The distributed NEMA and GEI Consultants, Inc. 5 components (input/output devices, control devices, and operator interface devices) are all connected by communications links and permit the transmission of control, measurement, and operating information to and fr
30、om many locations. domestic water use Water used for household purposes, such as drinking, preparing food, bathing, flushing toilets, watering lawns and gardens, and washing clothes, dishes, and dogs. About 85 percent of domestic water is delivered to homes by a public-supply facility, such as a cou
31、nty water department. About 15 percent of the nations residents supply their own water, mainly from wells. drawdown 1. The drop in the water table or level of water in the ground when water is being pumped from a well. 2. The amount of water used from a tank or reservoir. 3. The drop in the water le
32、vel of a tank or reservoir. electric current The flow of electric charges. electricity Physical conditions associated with the presence and flow of electric charges. energy savings performance contracts (ESPCs) A financing mechanism used by energy service companies (ESCOs) to make energy-efficiency
33、upgrades to facilities on behalf of the owner, which are then paid for with money resulting from the energy savings.1 enterprise fund reserves Enterprise fund reserves typically serve two purposes: 1) funding unanticipated or emergency repairs to utility infrastructure (e.g., water main breaks, pump
34、 failures, etc.) and 2) making up for revenue shortfalls due to variations in utility usage (e.g., lower water usage during drought conditions) to provide a financial buffer, avoiding the need to continually adjust rates to account for usage variations. The minimum level of reserves relative to inve
35、stments and operations costs is often defined in the debt covenants with the lender. equity The value of an investment in a facility. 1 For more information, go to http:/energy.gov/eere/slsc/energy-savings-performance-contracting. NEMA and GEI Consultants, Inc. 6 evaporation The process by which wat
36、er or another liquid becomes a gas (such as water vapor or ammonia vapor). feasible Capable of being accomplished within a reasonable period of time, taking into account economic, environmental, legal, social, and technological factors.2 feedback The circulating action between a sensor measuring a p
37、rocess variable and the controller that controls or adjusts the process variable. fixed costs Costs (e.g., rent, insurance, interest) that a utility must cover or pay even if there is no demand for water or no water to sell to customers. flow The continuous movement of a liquid from one place to ano
38、ther. fresh water Water that contains less than 1,000 milligrams per liter (mg/L) of dissolved solids; generally, more than 500 mg/L of dissolved solids is undesirable for drinking and many industrial uses. fuse A protective device that has a strip or wire of fusible metal that, when placed in a cir
39、cuit, will melt and break the electric circuit if heated too much. High temperatures will develop in the fuse when a current flows through the fuse in excess of that which the circuit will carry safely. gauge A device for checking or measuring a particular dimension of something, using specific stan
40、dardized units. For example, a gauge might measure the elevation of a water surface, the velocity of flowing water, the pressure of water, the amount or intensity of precipitation, or the depth of snowfall. Gauges are also used to determine the location or position of equipment during installation a
41、nd after operation. gravity flow Water or wastewater flowing from a higher elevation to a lower elevation due to the force of gravity. The water does not flow due to energy provided by a pump. Wherever possible, wastewater collection systems are designed to use the force of gravity to carry waste li
42、quids and solids. 2 California Water Code Section 8307 NEMA and GEI Consultants, Inc. 7 greywater Wastewater from clothes-washing machines, showers, bathtubs, lavatories and sinks. ground An expression representing an electrical connection to earth or a large conductor that is at the earths potentia
43、l or neutral voltage. groundwater Subsurface water in the saturation zone from which wells and springs are fed. In a strict sense, the term applies only to water below the water table. groundwater depth The distance of the groundwater table below the surface at any selected location. groundwater rec
44、harge The natural or intentional infiltration of surface water into the zone (ground) of saturation. groundwater table The average depth or elevation of the groundwater over a selected area. head The vertical distance, height, or energy of water above a reference point. A head of water may be measur
45、ed in either height (feet or meters) or pressure (pounds per square inch or kilograms per square centimeter). head loss The head, pressure, or energy (they are the same) lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness
46、 of the pipe, channel walls, or restrictions caused by fittings. Water flowing in a pipe loses head, pressure, or energy as a result of friction. Also called friction loss. headworks The facilities where wastewater enters a wastewater treatment plant. The headworks may consist of bar racks or bar sc
47、reens, comminutors, a wet well, and pumps. hectare A metric unit equal to 2.471 acres or 10,000 square meters hertz (Hz) The number of complete electromagnetic cycles or waves in one second of an electric or electronic circuit. Also called frequency of the current. NEMA and GEI Consultants, Inc. 8 h
48、ydraulic gradient The slope of the hydraulic grade line. This is the slope of the water surface in an open channel, the slope of the water surface of the groundwater table, or the slope of the water pressure for pipes under pressure. influent Water or other liquid raw (untreated) or partially treate
49、d flowing into a reservoir, basin, treatment process, or treatment plant. injection well A well constructed for the purpose of injecting water (including treated wastewater) directly into the ground. Water is generally forced (pumped) into the well for dispersal or storage into a designated aquifer. input horsepower The total power used in operating a pump and motor. , = ( ,)(100%) ,% interceptor A septic tank or other holding tank that serves as a temporary wastewater storage rese
