Copyright 2011, Toshiba Corporation. Toshiba International Corp - Houston Tx Jim Hartzel Section Mgr - Water / Waste Water Business 20 Yrs Field Service / Training Engr

Agenda Affinity Laws Basic Operation of a VFD VFD and Energy Savings $$$ Other Benefits of Using a VFD Questions and Comments welcomed any time

Variable Speed Drives in Pumping Applications Should we use a VFD on our Pump? Why ? Our Pump is running fine ! Should I buy a VFD ? Is it worth it ? Should I stick with my valve Throttling

Affinity Laws for Centrifugal loads 50% 100% 50% 12.5% Flow is proportional to Pump Speed (RPM) Power (KW) is Proportional to the cubed of Pump Speed (RPM)

Affinity Laws for Centrifugal loads Reduce Speed by 10% Reduces Flow by 10% Reduces Energy by 27%

. E NERGY S AVINGS There are applications where you need to change the amount of fluid you are pumping. There are FOUR ways you can do this: Regulate the discharge of the pump – Throttling Change the speed of the pump – VFD, Eddy Current clutch… Change the diameter of the impeller – Fixed speed Purchase a new pump – Fixed Speed

Basic Motor Characteristic RPM 0 Available Motor Torque Load Torque 1750RPM 1800R PM Pullup Torque Breakdown Torque Breakaway Torque Typical Nema B Speed Torque Curve 100% 60% 1777RPM Motor Current 100% 600% RPM = 120 Freq # Poles RPM = 120 x 60 4 RPM = = Constant #Poles = Fixed What's Left = Freq RPM = 120 x 40 4 RPM = 1200

Controlling Flow P Throttling Valve 200 GPM P Full Open 200 GPM 80% Speed 80%

Energy Savings

Example 1 - Utility Cost

Pump Example 1

Flow Rate

Pump Example 1 Return on Investment Break Even Pt

Pump Example 1 Energy Consumption: Throttling vs VFD

Pump Example 1 Annual Energy Usage: Throttling vs VFD

Pump Example 1 Annual Energy Savings: VFD

Pump Example 2

Flow Rate

Pump Example 2 Return On Investment Break Even Pt

Pump Example 2 Energy Consumption: Throttling vs VFD

Pump Example 2 Annual Energy Usage: Throttling vs VFD

Pump Example 2 Annual Energy Savings: VFD

Motor Starting Across Line Line Voltage Power line Disturbance Caused by Starting Across the Line Equipment shutting Off/Tripping High Peak Power $$$

VFD Features: V/F Curves VOLTAGEVOLTAGE FREQUENCY 0 100% 50% V/F Curve Eliminates High Inrush to motor

Accel / Decel 100% Speed 0 60 Sec Accel Rate Decel Rate 90 Sec 110 Sec Slowly Accelerates Motor Slowly Decelerates Motor Adjustable.1sec to 6000 sec

VFD Features: Energy Savings Curve VOLTAGEVOLTAGE FREQUENCY 0 100% 50%

Water Hammer 100% Speed 0 60 Sec Accel Rate Decel Rate 90 Sec 110 Sec Eliminate Water Hammer cause by sudden changes in pressure Adjustable.1sec to 6000 sec

VFD Features Adjustable Accel and Decel Rates Upper and Lower Limits Special V/F Curve for High Efficiency PID Control

. Reduced start inrush Unlimited starts per hour in most applications. Reduces Peak Demands. Power Factor Correction Higher PF (0.98) than running motors across the line Speed control Control process with changes in speed instead valves, vanes or dampers Energy Savings $$$$ Eliminates Water Hammer Saves wear and tear on equipment VFD B ENEFITS

Scada P VFD 4-20ma Flow sensor PLC VFD AC Power Typical Contol system

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. Typical Applications: Raw Water Pumps Return Activated Sludge Pump (RAS) High Service Pumps Low Service Pumps Blowers Chopper Pumps