Reliability in motion Welcome AWWA Motor

Reliability in motion ™ Welcome ! AWWA Motor Fundamentals Class 2012 • Presenter: Rick Fink of Toshiba International Corporation • 6 Years with Toshiba – Motors, Drives and Motors Controllers • 24 Years Electrical Power distribution, Motor Controls and Automation 1

Reliability in motion ™ Today we will cover: 1. 2. How motors work 3. Motor terminology 4. Motor failure 5. Energy savings 6. Motor – ASD considerations 7. 2 Motor styles Open questions

Reliability in motion ™ Toshiba International Headquarters – Houston, TX 3

Reliability in motion ™ Overview – TIC, Houston, Texas • • • Established 1970 Head Office/Factory located in Houston, TX. Annual Sales: ~ US$ 500 Million ~ 1, 000 ft 2 on 50 acres ~ 1100 Employees 3 Manufacturing Plants: Motors, Power Electronics, and Controls • Motor/ASD Test Lab (7 Dynamometers) • ISO-9001 Certification (Plant wide) 4 / Copyright © 2006 by Toshiba International Corporation

Reliability in motion ™ Motors – Styles Low Voltage Motors: • 115 v – 230 v 1 phase, 230 v – 460 v – 575 v 3 phase • Fractional to 1200 hp. Most are < 400 hp • General Purpose TEFC, ODP • 56 C Face • Inverter Duty Motors • Submersible • NEMA Design C Motors • Explosion Proof Motors (VFD Rated) • Stainless Steel “Food Grade Motors” 5

Reliability in motion ™ Styles of Motors 6

Reliability in motion ™ Styles and Horsepower Medium Voltage Motors: • Medium Voltage Motors (To 50, 000 Hp 15 KV) • ODP, WP II, TEFC, TEAAC, TEWAC, TEFV and Vertical Pump (500 Hp and UP) • 2300, 4160, 6600, 15 KV • Up to 4000 Hp 2300, 4160 V Manufactured in Houston, TX 7

Reliability in motion ™ How Does a Motor Work? n n Convert electrical energy into mechanical energy. 1831 - Faraday invented the magneto 1888 - Nikola Tesla invented the induction motor. 1896 - General Electric produced the first commercial induction motor. Nikola Tesla 1856 - 1943 8

Reliability in motion ™ Parts of a Motor Rotor/Stator Air Gap Stator Laminations Cooling Fan Stator Windings Rotor Drive Shaft Terminal Box 9 Bearing

Reliability in motion ™ Motor Rotor and Stator • Note the rotor looks like a “squirrel cage”. 10

Reliability in motion ™ Moving field in stator pulls rotor Figure 9 - The rotating magnetic field of an AC motor. 11

Reliability in motion ™ GLOSSARY OF FREQUENTLY OCCURRING MOTOR TERMS • FLA - Full Load Amps • The amount of current the motor can be expected to draw under full load (torque) • Also know as nameplate amps. • LRA - locked rotor amps • Also known as starting inrush, this is the amount of current the motor can be expected to draw under starting conditions when full voltage is applied. • Service Factor - Motor load and current rating when loaded to the service factor on the nameplate of the motor. Base is 1. 0 but for example, many motors will have a service factor of 1. 15, meaning that the motor can handle a 15% overload. The service factor amperage is the amount of current that the motor will draw under the service factor load condition. 12

Reliability in motion ™ Motor Terms • RPM is the rotational speed of the motor under full load conditions. It will always be less than the synchronous speed Ex 1800 rpm 4 pole motor will operate in the 1755 to 1765 rpm range. • Design – Torque profile 13

Reliability in motion ™ Motor Terms Continued • PHASE • Phase is the indication of the type of power supply for which the motor is designed Two major categories exist; single phase and three phase. • POLES • This is the number of magnetic poles that appear within the motor when power is applied. Poles always come in sets of two (a north and a south). Thus, the number of poles within a motor is always an even number such as 2, 4, 6, 8, 10, etc. • In an AC motor, the number of poles work in conjunction with the frequency to determine the synchronous speed of the motor. 14

Reliability in motion ™ Motor Terms Continued At 50 and 60 cycles, the common arrangements are: Poles - Synchronous Speed • 60 Cycles 50 Cycles • 2 - 3600 3000 • 4 - 1800 1500 • 6 - 1200 1000 • 8 - 900 750 • 10 - 720 600 POWER FACTOR • 15 Per cent power factor is a measure of a particular motor’s requirements for magnetizing amperage.

Reliability in motion ™ Frame Designations & Descriptions • NEMA (National Electrical Manufacturer’s Association) • National Electrical Manufacturers Association is a trade association. There are 17 member firms in the Motor and Generator Section. • NEMA Standards Publication No. MG 1 - 1998 MOTORS AND GENERATORS is the most widely cited standard for motors in the U. S. , it has a 5 -year revision cycle. • NEMA Defines critical dimensions: mounting holes shaft height, and diameter, as well as shaft length. • NEMA has set up frame designations relative to Horsepower Rating and Rpm. Example: a 1 hp 1800 rpm is in a NEMA 143 T Frame and a 100 hp 1800 rpm motor is in a 404 T or TS frame. 16

Reliability in motion ™ NEMA frame dimension measurements ensure interchangeability. 17

Reliability in motion ™ Basic Motor Design A Discussion on Torque 18

Reliability in motion ™ Torque and HP. Torque is turning effect. Horsepower is the rate of doing work. • Torque is described in foot-pounds • By definition, one horsepower equals 33, 000 footpounds per minute Consider: HP = Speed in RPM x 2 P x torque 33, 000 1 pound Or: Torque and Foot-Pounds HP = torque (lb-ft) X RPM 5250 And: 1 foot Torque (lb-ft) = HP x 5250 RPM This involves torque at a steady speed. Since additional torque is necessary to overcome the inertia of starting, starting torque will be higher than rated load torque 19 The force of one pound is needed to turn the wheel at a steady rate. Therefore, the torque is one pound times one foot or one foot-pound.

Reliability in motion ™ Basic Motor Design Torque – Twisting (rotational) Force A Motor is a Time – Rated, Torque Device Torque Components: Locked Rotor (Pull in) Torques Pull Up Torques Breakdown Torques Locked Rotor Amps WK 2 Capabilities 20

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Reliability in motion ™ Motor Torque Designs • • maximum 5% slip • high to medium starting current • normal locked rotor torque • normal breakdown torque • suited for a broad variety of applications - as fans and pumps • NEMA design B • maximum 5% slip • low starting current • high locked rotor torque • normal breakdown torque • 22 NEMA design A suited for a broad variety of applications, normal starting torque - common in HVAC application with fans, blowers and pumps

Reliability in motion ™ Design Torque continued • • maximum 5% slip • low starting current • high locked rotor torque • normal breakdown torque • suited for equipment with high inertia starts - as positive displacement pumps • NEMA design D • maximum 5 -13% slip • low starting current • very high locked rotor torque • 23 NEMA design C suited for equipment with very high inertia starts - as cranes, hoists etc.

Reliability in motion ™ Torque / Inertia Capabilities The Horsepower listed on the nameplate of a motor is a statement of the Torque it will produce at a set RPM for defined period of time Horsepower = Torque X RPM 5252 24

Reliability in motion ™ Torque / Inertia Capabilities A 10 HP 1800 rpm TEFC NEMA B Electric Motor will develop 30 ft-lbs. of torque at 1800 rpm continuously and meet certain minimum performance criteria as defined by NEMA 30 ft-lbs Torque = 10 Hp X 5252 1800 RPM 25

Reliability in motion ™ Torque / Inertia Capabilities Electric motor will continue to produce Horsepower = Torque X RPM 5252 Until --- 26

Reliability in motion ™ Torque / Inertia Capabilities • It Stalls “Breakdown Torque” or - preferably • Motor overload relay trips or • Burns out (Exceeding temperature/time capability of insulation) or • 27 Exceeds mechanical strength of bearings, shaft, or frame.

Reliability in motion ™ Speed-torque Curves: 28

Reliability in motion ™ Choosing the right motor: 29

Reliability in motion ™ Torque / Inertia Capabilities Advantages of higher Torque • • Ability to accelerate high inertia loads • Startup and operating capabilities during brownouts • 30 Prevents stalling in tough applications Reduced voltage starting

Reliability in motion ™ Choosing the right motor Some points to consider when specifying a new motor: • Horsepower • Speed (poles) • Voltage • Efficiency • Torque (design letter) 31 • Dimensional constraints (frame size) • Unusual service conditions • Enclosure • Coupling vs. Pulley drive

Reliability in motion ™ Motor Nameplate 32

Reliability in motion ™ Motor Request Worksheet • NAMEPLATE DATA: • HP _____ RPM_____ Voltage_______ HZ____ Phase_____ FLA _____ Frame _____ • Enclosure: ___________ {Write it down or Circle the enclosure} • TEFC (Totally Enclosed Fan Cooled) • ODP (Open Drip Proof) • TEBC • Wash Duty / Stainless Steel • Brake Motor • Exp. Proof – Division_____ Class_____ Group_____ • Options / Modifications: (Write down if they have modifications. Modifications / options could be: using a tach or encoder, bearing RTDs, TENV (Totally Enclosed Non-Ventilated) (Totally Enclosed Blower Cooled) – This is usually a Vector Duty / ASD motor with a CT Speed Range of 120: 1 or 1000: 1. 841 motor winding RTDs, Thermostats (klixons), F 2 mounting, etc. )_________________________________ 33

Reliability in motion ™ Frame Designations & Descriptions For Low Voltage Motors • • TEFC – Totally Enclosed Fan Cooled – Motor is Totally Enclosed and is cooled with a Fan blowing over the frame of the motor. Internal air is being circulated by internal fins on the rotor that act as a fan. Can be used in dirty, moist, or mildly corrosive operating conditions. • TENV – Totally Enclosed Non Vented - The motors body is being used as a heat sink to dissipate the heat buildup. Normally seen in small horsepower motors. • 34 ODP – Open Drip Proof – No direct protection for the windings or the bearings. Air is enters through the lower ports and exhausted through the top vents. Ventilation openings prevent liquids or solids from entering the motor at any angle less than 15 degrees from the vertical. TEAO – Totally Enclosed Air Over – Designed as a TENV but must be mounted within an air stream to properly dissipate heat.

Reliability in motion ™ Open Drip Proof Motor 35

Reliability in motion ™ TEFC Enclosure 36

Reliability in motion ™ Frame Designations & Descriptions For Low Voltage Motors • TEXP – Totally Enclosed Explosion Proof – Motor carries a U. L. Label for Class 1 Division 1 Group D and Class 1 Div 2 Groups E, F, and G. Used primarily in Explosion Proof applications. • Severe Duty – No NEMA Designation • Mill and Chemical Duty - Not a NEMA Designation • IEEE 841 – Institute of Electrical and Electronics Engineers NEMA Designations end at 200 Hp 37

Reliability in motion ™ Terminal Box Designations for Low Voltage Motors • F 1 – Standard configuration – When looking at the motor from the Fan End, (ODP) the Terminal Box (T-Box) will be on the RIGHT side of the motor. • F 2 – When looking at the motor from the Fan End, (ODP) the Terminal Box (T-Box) will be on the LEFT side of the motor. • This is true for all motor manufacturers 38

Reliability in motion ™ What Causes of Motor Failure? n n 39 Insulation. . . . … 20% Bearings. . … 80%

Reliability in motion ™ Motor Cooling Choosing the correct motor for the application is by far the best ways to keep it cool. Heat will destroy a motor ► The life of the insulation is reduced in half for each 10°C increase in temperature. ► Insulation life, when operated at its rating, is 20, 000 hours, with 90% reliability. “Average life” is 100, 000 hours on sinusoidal power. ► Heat reduces insulation life even more when the motor is operated on VFD power supply. ► Lubrication life is cut in half for every 15 degrees Celsius rise 40

Reliability in motion ™ Insulation Life Insulation Design / Temperature Rise The life of a class of insulation at rated temperature is 40, 000 hours (4. 55 years) A class F insulation system with a B rise will have an expected life of 200, 000 hrs (22. 8 years) when operated at nameplate horsepower and speed 41

Reliability in motion ™ Causes of Motor Failure n Insulation u u u 42 Voltage spikes Excessive Number of Starts Contaminants Excessive Load Inertia Singe Phasing Locked Rotor Overload – Motor controllers are designed to do this but. . High Ambient Ventilation Failure Thermal Aging Vibration

Reliability in motion ™ NEMA INSULATION TEMPERATURE RATINGS Insulation systems are arranged in their order of insulation level and classified by a letter symbol or numerical value: ► Class B / Class 130° C 266° F ► Class F / Class 155° C 311° F ► Class H / Class 180° C 356° F The temperature classification indicates the maximum (hot spot) temperature at which the insulation system can be operated for normal expected service life. 43

Reliability in motion ™ Causes of Motor Failure n Bearings u u u 44 Over lubrication Under Lubrication Grease – Limited by Temperature, Time and Contaminants Thrust Side Loading Vibration Bearing Currents High Ambient Fatigue. . L 10 Undersized Bearings Improperly designed Shaft Support System

Confidential Do you know how much Electric Motors Cost You? Copyright © 2005 Toshiba

Reliability in motion ™ Efficiency values for industrial motors - NEMA PREMIUM™ • Table 12 -11 (in NEMA MG 1 -1998 Rev 2) shows “Full Load Efficiencies of Energy Efficient Motors”, up to 500 HP. • Those motors having nominal full-load efficiency greater than the values in that table may be classified as “energy efficient. ” (NEMA MG 1 -1998 Rev 2, 12. 59) 46

Reliability in motion ™ Do you know how much Electric Motors cost you? Cost New Cost to Operate • 100 Hp $4, 146 $35, 730 • 75 Hp $3, 378 $27, 092 • 50 Hp $1, 860 $18, 141 • 20 Hp $809 $7, 445 47 /

Reliability in motion ™ 20 Year Life Cycle Cost 48 /

Motor Construction Each Motor is 10 HP, 1200 RPM Reliability in motion ™ Standard efficiency 84% 49 / Epact efficiency 87. 5% Premium Efficiency 90. 2%

Reliability in motion ™ Why is Improving Motor Efficiency Important? • Saving money • The country will continue to electrify • Over 50% of all Electrical Energy consumed in the USA is used by Electric Motors. Do you know how many Motors you have in your Home? • 80% of the Electrical Energy consumed in US industry is used by Electric Motors. Improving the efficiency of Electric Motors and the equipment they drive can save energy and reduce operating costs. 50 /

Reliability in motion ™ Global Consumption • Pumps • Fans • Compressors for Cooling/Compressed Air • Industrial Handling & Processing • Transport Source: Paul Waide/Conrad U. Brunner 2010 51

Reliability in motion ™ When should you consider buying a new Premium Motor? New Premium Motors should be considered in the following cases: • For all new installations • Purchasing new equipment packages, Air Compressors, HVAC Systems, and Pumps • Major modifications made to facilities or processes • Instead of rewinding older Motors • Replace oversized and under loaded Motors • Part of a Preventive Maintenance or Energy Conservation Program 52 /

Reliability in motion ™ Should I rewind a failed Motor? Failed Motor usually can be rewound, it is often worthwhile to replace a damaged motor with anew NEMA Premium Motor to save energy and improve reliability. • Motor is less than 75 Hp. • Cost to rewound exceeds 65% of the price of a new Motor. • Motor was rewound before 1980. 53 /

Reliability in motion ™ Motor Energy Savings Opportunities 54

Confidential Variable Frequency Drives Variable Speed Drives Adjustable Frequency Drives AC Inverter AC Drive

Confidential • The electric AC Motor is over 100 Years old • When voltage is applied to the motor it accelerates to full speed as fast as it can both mechanically and electrically • Throughout time people tried to find ways to slow down the speed of the motor to be able to apply it to a wider range of applications in manufacturing • The first method was to increase the “poles” of the motor to reduce speed; 2 Pole = 3600 Rpm, 4 Pole = 1800 Rpm, 6 Pole = 1200 Rpm, 8 Pole = 900 Rpm; etc. 56 Copyright © 2005 Toshiba International Corporation. All rights reserved.

Reliability in motion ™ Drives - A Historical Summary 57

Reliability in motion ™ The Mechanical Variable Speed Drive. Using mechanical means through the use of belts, and varying the diameter of pulleys, variable speed is possible. • Features • Mature Technology (been around forever and still used today) • Simple, easy to understand • Relatively low cost • Limitations • Belt/sheave wear • Special start-up/shutdown procedures required for high inertia loads • High Maintenance • Reduces bearing life in motors 58 Mechanical Variable Speed Drive Variable speed shaft AC Motor Variable pitch diameters

Reliability in motion ™ Pulse Width Modulated Drive (PWM), (AFD), (ASD) A diode bridge creates a constant voltage DC, which is chopped into adjustable output frequencies which control motor speed. • Features • Uses standard induction motors (should have “Inverter Rated” insulation system) • Good efficiency at full speed, full load • High displacement power factor • Bypass capable • Good with high inertia loads • Easy installation • No tach feedback required • Remote control possible • Drive can be tested unloaded • More than one motor can be connected to one drive • Open circuit protection • Common bus regeneration • Smooth low speed operation • Closed & Open Loop Vector control performance (optional) • Ride through options available • Limitations • Susceptibility to line transients • Current harmonic distortion, dependant on line impedance • High frequency content in PWM • Initial cost is high • Extra hardware for regeneration • Motor noise • Full power conversion required • High service costs 59 Pulse Width Modulated AC Drive Line Converter Inverter Motor Constant volt DC bus

Reliability in motion ™ Why use Variable Frequency Drives ? • Vary the speed of AC motor by controlling voltage and frequency. • Increased process control over conventional valves and dampers. • Inherent soft start feature reduces mechanical and electrical shock to motor and driven mechanical equipment. • Decrease or eliminate pump cavitation. • Decrease maintenance costs. • Increase mechanical efficiency by eliminating friction from valves and dampers. • AKA: Save money on the user’s power bill. • Typical variable torque application can pay for additional cash outlay within 12 -18 months. 60

Reliability in motion ™ Laws of Affinity • Centrifugal pump: Load varies as the square of the change in speed. • Centrifugal fan: Load varies as the cube of the change in speed. • Energy savings predicated on these concepts. 61

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Reliability in motion ™ Energy Savings • Most centrifugal devices designed for worst case operating conditions. • Typical fan and pump applications can operate at 30% below design point, save $$ in the form of energy savings. • If operating on co-gen power system, ASD will increase amount of power available for resale back to utility. 63

Reliability in motion ™ ASD – Motor Considerations • When using an adjustable speed drive to control a motor there additional considerations: 1. 2. Motor cooling. 3. Load torque requirements 4. Motor bearing protection - Fluting 5. 64 Motor speed range. Motor lead length

Reliability in motion ™ Motor Drive PWM Modulation Natural Commutation Voltage Current Input 65

Reliability in motion ™ Motor Drive with long leads • Voltage Spikes can damage Motor & Cable insulation • Drive’s voltage pulses are • Thousands of spikes per second Drive’s Voltage 66 / Copyright © 2007 Toshiba International Corporation. All rights reserved. Motor’s Voltage

Reliability in motion ™ Example of PWM voltage damage to motor wiring What A Failure Might Look Like 67

Reliability in motion ™ Example of Bearing Damage due to ASD PWM Output Fluting 68

Reliability in motion ™ Summary • Choose the right size (power) motor. • Pick motor features to match environment. • Protect the motor. • Energy efficient motors and their use with ASD’s can save money and improve system performance. 69