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Analysis and procedure for the energetic optimisation of pumps in water supply applications"Pump check"Rough check -Calculation tool explained by means of a fictional example

DisclaimerPump rough check - disclaimerThis product has been developed for supporting the decision making process of energy-saving measures at pumps in water supply applications. A warranty for the correctness and completeness of the obtained results and information can not be given. Principally, any liabilities are excluded that are referred to material or more imaginary damages caused by the use or disuse of the presented information or the use of incorrect and incomplete data.

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FC recommendationPump rough check: Summary of the resultsData of the exemplary water supply applicationPumpManufacturerExemplary pumpNominal flow rate20[l/s]Nominal pump head30[m]MotorManufacturerExamplary motorPmech7.5[kW]Rated voltage400[V]Rated current16[A]Measurements at the duty pointFlow rate18[l/s]Pump head25[m]Current (mean value)14[A]Pump unitTotal efficiency, actually53%Results of the rough checkTotal efficiency, optimum value0%Energy efficiency E=0.00How close is the actual condition to the technical optimum?0Potential for energy savings0%0Potential for energy savings0[kWh/a]Savings of energy costs0[CHF/a]0CHF over a lifetime of 15 yearsValidation of sizing parameters Q & HDifference of pump head (H-Hdyn)/H17%[-]okDifference of flow rate (Q-Qeff)/Q10%[-]okRecommendation for further procedure: Is a fine check recommended?Fine check due to the potential for savings?00Fine check due to the difference of the pump head?NOThe actual pump head differs less than 20 % compared to the sizing pump head.Fine check due to the difference of the flow rate?NOThe actual flow rate differs more than 20 % compared to the sizing flow rate.Fine check due to the qualitative statement to motor, pump and total system?YESBased on the qualitative statement to motor, pump and total system a fine check is necessary.Fine check due to the pump size?NOThe framesize of the pump alone calls not for a fine check.For reasons mentioned above follows:0What is a fine check?The fine check is a detailed energetic analysis of the water supply, where the profitability of a pump replacement or another energy-saving measure is shown.

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HelpPump rough check - help filePlease print this sheetand keep it at hand for the rough check.Inputs from nameplate: Read out the data!Measurements: MEASURE only, do NOT CALCULATE!Calculation: Will be done automatically!General questionsPrioritisation of the pumps (the higher the number, =(lifetime * power)/year of manufacture... the rather a rough check should be done) or:a system change has been madeImportant:- for pumps controlled by frequency converter: Set frequency converter to 100 % (50 Hz).- Switch off the blind current compensation or measure the current between the blind current compensation and the motor terminals (best directly at the motor terminals).MeasurementsThree measurements are made:- manometric pump head in metre: Therefore a pressure gauge is needed. Mostly one is installed on the discharge side of the pump.Furthermore, the pressure on the suction side of the pump has to be estimated, if no pressure measurement is installed on the suctionside. Help to this offers the table sheet "Pump head calculation" with three sketches of the most widespread cases.- flow rate in litre per second [l/s]: Mostly a magnetic flow meter is already installed and has only to read out. If no magnetic flowmeter exists, a mobile measurement of the flow has to be made.- current in ampere [A] of the three phases of the electric motor: This measurement is done by means of an amps clamp.Example of an amps clamp:ConstantsAccelaration of gravityg=9.81[m/s2]Density of water=1,000[kg/m3]Maximum current difference between the phases (motor)5%limit for fault alarmLifetime of the pump15yearsInput:Information about the water supply systemWater supply companyPlease state the address, contact person, phone number, etc.What pump type is installed?Contact personPosition of contact personAddressCip codeCityPhone numberE-mailLocation of the pump stationWhat pump type is installed?Input:Annual dataOperating hours per yearh/aHow many hours does the pump run per year?Electricity consumption per year, motorkWh/aCurrent this motor uses per year in kWh/a.Pumped water amount per year, pumpm3/aWater amount pumped per year in m/aEnergy priceCHF/kWhWhat is the average price for a kWh incl. tariff loading at peak periods and low/high tariff?Input:Sizing data of pump (read from nameplate)Make / manufacturersee pump nameplateSerial numbersee pump nameplateKind of pump / designsee pump nameplateDry installed(yes/no)Submersible pump? Dry installed pump?Submersible pump(yes/no)Number of stages (in case of high pressure pumps)Single stage low pressure pump(yes/no)In the two green fields on the left "yes" or "no" have to be entered!Multistage high pressure pump(yes/no)Number of stages[-]In case of mutistage high pressure pumps the number of stages has to be entered here. Default value = 1.Flow rate of the pump, sizing dataQ[l/s]see pump nameplatePump head, sizing dataH[m]see pump nameplateInput:Sizing data of motor (read from nameplate)Make / manufacturersee motor nameplateSerial numbersee motor nameplateMotor type / designsee motor nameplate(Mechanical) rated motor powerPn=Pmech[kW]see motor nameplate - in kW!Rated motor speednn[1/min]see motor nameplateMotor efficiency at nominal loadn[-]see motor nameplateRated motor currentInAsee motor nameplatecos at nominal loadcos n[-]see motor nameplateRated motor voltageUn[V]see motor nameplateMeasurement:Measurement at duty point (when pump is running!!!)Effective flow rateQeff[l/s]How many litres per second are pumped at the duty point?Measured pump headHdyn[m]What is the pump head of the pump at the duty point? See also table sheet "Pump head calculation". Thereto click on the blue link.Does the pump head vary?(much / little / don't know)State, if possible.Current measurementDoes a blind current compensation exist?(yes / no / don't know)Switch off the blind current compensation or measure the current between the blind current compensation and the motor terminals (best directly at the motor terminals).Is a frequency converter switched on?(yes / no / don't know)State, if a frequency converter exists, otherwise leave field empty.If yes, on which frequency is it set?[Hz]Current, phase 1Iphase1[A]Please measure each phase separately. Caution: The frequency converter has to be set to 50 Hz and the measurement has to be done at the motor terminals.In case of a submersible pump measure the current at the cables coming out of the control cabinet.Current, phase 2Iphase2[A]Current, phase 3Iphase3[A]Gen. questions:General status recording for pump & motorCan it be seen that renewal, optimization and/or reconstruction is needed actually?Motor(yes / medium-term / no / don't know)Pump(yes / medium-term / no / don't know)Total system(yes / medium-term / no / don't know)If yes, please describeEstimation of the repair/maintenance costsMotor(high / normal / low / don't know)Pump(high / normal / low / don't know)Total system(high / normal / low / don't know)ChangesHave changes regarding the operation or piping(new pipes, ...) been made since thecommissioning of the pump?(yes / no / don't know)If yes, what has been changed?

&L&8&Z&F&R&8&P / &NYR:Big source of error!Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:In 99.5 % of cases 400 V!YR:The efficiency or cosphi is requiredYR:The efficiency or cosphi is requiredYR:Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:The higher this number is, the rather a rough check has to be made.

Rough checkPump rough check - calculationsCorrective factor for the calculation of the optimum pump efficiencyColor key:FromReto Baumann, Hny AG, JonaInputs from nameplate: Read out the data!Date2/17/09Measurements: MEASURE only, do NOT CALCULATE!AdaptionY. Roth, Ryser Ingenieure AGCalculation: Will be done automatically!General questionsMaximally reachable efficiency in case of single stage pumps as a function of nqPrioritisation of the pumps (the higher the number, =(lifetime * power)/year of manufacture(covers with nq 10 - nq 100 the range of centrifugal pumps where the flow passed through radially and diagonally)... the rather a rough check should be done) or:a system change has been madenq - rangeImportant:fromtoETA hydr., max. (approximate)- for pumps controlled by frequency converter: Set frequency converter to 100 % (50 Hz).102570%- Switch off the blind current compensation or measure the current between the blind current compensation and the motor terminals (best directly at the motor terminals).263075%313580%365584%567583%7610082%ConstantsAccelaration of gravityg=9.81[m/s2]Weighting according to frame size:Density of water=1,000[kg/m3](smaller frame sizes have a lower efficiency due to their construction)Maximum current difference between the phases (motor)5%limit for fault alarmLifetime of the pump15yearsnq - rangeQ - rangeCorrective factor for ETA hydr.Input:Information about the water supply systemfromtofromto1030110l/s0.9Water supply systemExemplary watersupply system1120l/s0.9521l/s1Contact person30351120l/s0.9Position of contact person2140l/s0.9541l/s1AddressFor all other variants factor 1 can be used for calculation.Zip codeWeighting according to the number of stages(multistage pumps with a high number of stages have a lower efficiencyCitydue to redirection losses)Phone numberNumber of stagesE-mailfromtoCorrective factor for ETA hydr.241Location of the pump station580.999120.98What pump type is installed?13170.9618220.93Input:Annual dataOperating hours per year4,000h/aElectricity consumption per year, motorkWh/aPumped water amount per year, pumpm3/aEnergy price0.15CHF/kWhInput:Sizing data of pump (read from nameplate)Make / manufacturerExemplary pumpSerial number74.115.1996Kind of pump / designDry installed pumpyes(yes/no)okSubmersible pumpno(yes/no)Number of stages (in case of high pressure pumps)Single stage low pressure pumpyes(yes/no)okMultistage high pressure pumpno(yes/no)Number of stages1[-]Flow rate of the pump, sizing dataQ20[l/s]0.02m3/sPump head, sizing dataH30[m]Input:Sizing data of motor (read from nameplate)Make / manufacturerExamplary motorSerial number12.345.1997Motor type / design(Mechanical) rated motor powerPn=Pmech7.5[kW]7,500[W]0Rated motor speednn1,455[1/min]Motor efficiency at nominal loadn0.82[-]Rated motor currentIn16Acos at nominal loadcos n0.9[-]Rated motor voltageUn400[V]Measurement:Measurement at duty point (when pump is running!!!)Effective flow rateQeff18[l/s]0.018m3/sMeasured pump headHdyn25[m]Hint pump head calc. (click here)Does the pump head/flow rate vary?(> +/-10 %)(yes / no / don't know)Current measurementDoes a blind current compensation exist?(yes / no / don't know)Is a frequency converter switched on?(yes / no / don't know)If yes, on which frequency is it set?[Hz]Phase check:Current, phase 1Iphase114[A]okCurrent, phase 2Iphase214[A]okCurrent, phase 3Iphase314[A]okGen. questions:General qualitative statements to pump, motor and total systemCan it be seen that renewal, optimization and/or reconstruction is needed actually?Motormedium-term(yes / medium-term / no / don't know)Pump(yes / medium-term / no / don't know)Total system(yes / medium-term / no / don't know)If yes, please describe.Estimation of the repair/maintenance costsMotor(high / normal / low / don't know)Pump(high / normal / low / don't know)Total system(high / normal / low / don't know)ChangesHave changes regarding the operation or piping(new pipes, ...) been made since thecommissioning of the pump?yes(yes / no / don't know)If yes, please describe.Calculation:Total efficiency - ACTUAL value (processing of input values (actual status))Calculation of hydraulic power (duty point)Phyd =4,415[W]4.4[kW]Calculation of electrical poweralternatively:Electrical power at nominal loadPelectr, n=9,977[W]10.0[kW]9,146[W]Approximation: current measurementApproximate coefficient (R. Tanner)po-0.342Approximate coefficient (R. Tanner)px1.345Load ratioPelectr/Pelectr,n=0.83okElectrical power at duty pointPelectr=8327[W]8.3[kW]Total efficiency, ACTUAL valuetot, measured=0.53[-]Calculation:Total efficiency - OPTIMAL valueNumber of pole pairsppz2[-]Specific speednq =17.5withnn [1/min] (approximation)Qeff [m3/s]H [m] = Pdyn/number of stages,if multistageWeighting according to impeller type: Table, which shows the maximal reachable hydraulic efficiency as a function of nq.hydr, max.=0.70Weighting according to frame size (Q): Smaller pumps have due to their construction a lower efficiency than larger pumps with the same speed (nq).Corr. factor=0.95Reduction in case of large number of stages with empiric coefficient frCorr. Factor=1Best possible pump efficiencypump, opt=0.67Best possible mechanical powerPmech,opt=6,638[W]6.6[kW]Best possible motor efficiencymotor,opt=Wrong data!Interpolation in table sheet "Best motors"Electrical power in optimumPel,opt=0.0[W]0.0[kW]Total efficiency, OPTIMAL valuetotal,opt=0.00[-]Result:Comparison of ACTUAL and OPTIMAL valueEnergy efficiency (E coefficient) (must be 1, then input error.YR:Was 31 (R. Baumann), but results in a "noman's land" between 30 and 31! Therefore reduced to 30!YR:Hydraulic power at duty point!YR:Duty point!

Speed is nominal speed (approximation!) -> Info RBYR:Big source of error!Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:In 99.5 % of cases 400 V!YR:The efficiency or cosphi is required.YR:The efficiency or cosphi is required.YR:Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:Please enter MEASURED parameters only. Do NOT CALCULATE anything!YR:If the power is > 375 kW, recommend always directly a fine check!YR:In the two green fields on the left "yes" or "no" have to be entered!YR:In the two green fields on the left "yes" or "no" have to be entered!YR:Calculated with Pmech and etamotor.YR:Calculated with U, I, square root (3), cos (phi).YR:The higher this number is, the rather a rough check has to be made.Hint pump head calc. (click here)Hint pump head calc. (click here)

Best motorsMotors with efficiency category IE3 (dry installation)Sourcehttp://www.motorsystems.org/downloadsFromRonald TannerEfficiencies in %Mech. powerMotor power,interpolationEfficiencieskW2-pole4-pole6-poleAuxiliary values[kW]X2-pole4-pole6-pole0.880.782.578.91.1Validity of approximation method by R. Tanner6.65.5lower limit89.289.6881.182.784.1811.57.5upper limit90.190.489.11.584.285.382.52.22.285.986.784.33.0Extrapolated efficiencies3.087.187.785.64.02-pole4-pole6-pole4.088.188.686.85.5Number of pole pairs1235.589.289.6887.5Efficiency89.790.188.67.590.190.489.111.011.091.291.490.315.015.091.992.191.218.518.592.492.691.722.022.092.79392.230.030.093.393.692.937.037.093.793.993.345.045.09494.293.755.055.094.394.694.175.075.094.79594.690.090.09595.294.9110.0extended by R. Tanner110.095.295.495.1132.0132.095.495.695.4160.0160.095.695.895.6200.0200.095.89695.8220.0220.095.89695.8250.0250.095.89695.8300.0300.095.89695.8330.0330.095.89695.8375.0375.095.89695.8highestMotors of submersible pumpsSourceempiricFromReto BaumannMech. powerMotor power,interpolationEfficienciesDate6/4/09[kW]X2-pole4-pole6.65.5lower limit8888.5kWEfficiencies7.5upper limit8888.5(P2M)2-pole4-poleAuxiliary values0.882.082.51.1Extrapolated efficiencies1.183.083.51.52-pole4-pole1.584.084.52.2Number of pole pairs122.285.085.53.0Efficiency88.088.53.086.086.54.04.087.087.55.55.588.088.57.57.588.088.511.011.088.088.515.015.088.589.018.518.588.589.022.022.088.589.030.030.088.589.037.037.089.089.545.045.089.089.555.055.089.089.575.075.089.590.090.090.089.590.0110.0110.089.590.0132.0132.090.090.5160.0160.090.090.5200.0200.090.090.5220.0220.090.090.5250.0250.090.090.5300.0300.090.090.5330.0330.090.090.5375.0375.090.090.5

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Best motors

2-pole4-pole6-polePower [kW]EfficiencyEfficiency, 0.8 - 75 kW

Pump head calculation

2-pole4-pole6-polePower [kW]EfficiencyEfficiency, 90 - 375 kW

Instruction: Principally, three scenarios exist for pumping of water in water supply applications. Please select one, enter the required values and transfer the value of the field "Pump head=" into the table sheet "Rough check".(Use the link to find the right place.)Suction tank above the pumpPlease enter the values being measured (Enter only measured data. Do not calculate values!):H1mHeight difference between pump and water level in the suction tank [m]H2mHeight difference between pump and water level in the upper reservoir [m]M1barPressure gauge indication. Pressure gauge on suction side, installed between suction tank and pump [bar]M2barPressure gauge indication. Pressure gauge on discharge side, installed between pump and reservoir [bar]Enter the below value (in metre of water) in the table sheet "Rough check" (click here)Pump head Hdyn=0mH2O (metre of water)Suction tank / ground water impoundment below pumpPlease enter the values being measured (Enter only measured data. Do not calculate values!):H12mHeight difference between water level in the suction tank / ground water and pump [m]H223mHeight difference between pump and water level in the reservoir [m]M1-0.2barPressure gauge indication. Pressure gauge on suction side betw. suction tank/ground water and pump [bar]M22.2barPressure gauge indication. Pressure gauge on discharge side, installed between pump and reservoir [bar]Enter the below value (in metre of water) in the table sheet "Rough check" (click here)Pump head Hdyn=25mH2O (metre of water)Submersible pumpPlease enter the values being measured (Enter only measured data. Do not calculate values!):HmHeight difference between water level in the suction tank / ground water and reservoir; H = Z2 - Z1 [m]Hw-mmHeight difference between water level in the suction tank / ground water and pressure gauge M1 [m]M1barPressure gauge indicationEnter the below value (in metre of water) in the table sheet "Rough check" (click here)Pump head Hdyn=0mH2O (metre of water)1 bar =10.2mH2O

&L&"Arial,Fett"&8Pumpencheck&C&"Arial,Fett"&18Erfassung Frderhhe: Messungen bei laufender Pumpe!&R&8Projekt Nr. 4054/025&L&8&Z&F&R&8&P / &NPump headPumpSuction tankPumpSuction tank,ground waterSuction tankground waterSubmersible pumpEnter the below value (in metre of water) in the table sheet "Rough check" (click here)Enter the below value (in metre of water) in the table sheet "Rough check" (click here)Enter the below value (in metre of water) in the table sheet "Rough check" (click here)Enter the below value (in metre of water) in the table sheet "Rough check" (click here)Enter the below value (in metre of water) in the table sheet "Rough check" (click here)Enter the below value (in metre of water) in the table sheet "Rough check" (click here)