A.O.Smith Motor Master y University

Transcription

1 HVAC&R Book 9/6/56 2:54 AM Page 1 A.O. SMITH HEATING, VENTILATING, AIR CONDITIONING & REFRIGERATION MOTORS Motor Master y Uiversity GENERAL PURPOSE MOTORS SPECIAL PURPOSE MOTORS APPLICATION INCLUDES: APPLICATION INFORMATION TROUBLESHOOTING OTHER MODULES INCLUDE: PUMP MOTORS

2 HVAC&R Book 9/6/56 2:54 AM Page 2 NOTICE: The iformatio cotaied i this booklet is geeral i ature ad is draw from sources believed to be reliable. It is iteded for geeral iformatio purposes oly. The descriptios i this booklet may ot apply to a particular motor or a particular applicatio. No warraties are iteded to be created by this iformatio. Cotets Heatig, Vetilatig, Air Coditioig & Refrigeratio (HVAC&R): Geeral Purpose & Special Purpose Itroductio HVAC&R The Refrigeratio Cycle Hermetic Compressors HVAC&R Basics Outdoor Sectios Residetial Furaces Fa Coil Uits Room Air Coditioers PTACs (Packaged Termial Air Coditioers) Air Curtais Evaporative Coolers Uit Heaters Hot Water Circulators Whole-House Vetilators Pedestal Fas Miscellaeous Fa Blade ad Blower Wheel Basics Rotatio Geeral Purpose Motors Power Tools Special Purpose Motors Glass Washers Garage Door Opeer/Commercial Door Opeer/Gate Motor s Air Compressors Carboator Pump Sump Pump Sewage/Effluet Pumps Explosio Proof Applicatios Poultry Duty Fa Motors Trasformer Coolig Fa Motors Motor Troubleshootig Guide A.O. Smith Corporatio

3 HVAC&R Book 9/6/56 2:54 AM Page 3 Heatig, Vetilatig,Air Coditioig, & Refrigeratio Motors 1 Itroductio This applicatio guide is ot iteded to be a repair maual for ay of the equipmet described. It is iteded to provide geeral kowledge to persos workig i fields related to electric motors ad to provide service iformatio to qualified persos. Motors are of little use by themselves. They are desiged to be coupled to some other part ad covert electrical eergy ito mechaical eergy. The selectio of a replacemet motor for a specific applicatio would be a very ivolved process if it were ecessary to start with the basics of magetism, electricity, ad motor costructio each time a replacemet was required. I order to preset replacemet motor offerigs i a logical, orderly maer, the motors are grouped by type, costructio, ad ofte, the applicatio for which they are iteded. Motors i origial applicatios are desiged to be operated uder specific coditios. If the equipmet or istallatio is modified, the motor may be overloaded. For example, if a furace desiged for use i a home with duct work is placed i a shop ad has little or o supply duct work, it may be close to a free blow coditio (o static pressure or resistace to air flow). The motor may become overloaded. A.O. Smith s replacemet motor selectios are idetified by applicatios where possible. This makes it easier to arrow the choices i the selectio process.

4 HVAC&R Book 9/6/56 2:54 AM Page 4 2 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors Heatig, Vetilatig, Air Coditioig & Refrigeratio (HVAC&R) HEATING, VENTILATING, AIR CONDITIONING & REFRIGERATION (HVAC&R) Heatig ad air coditioig applicatios ofte use the same types of motors or share the same motors if the systems are combied. Heatig systems usig motors heat either air or water. Oce heated, the air or water is moved by a motor ad blower or motor ad pump. All air coditioig systems usig motors withi the scope of this maual use essetially the same priciples. The compoets may look differet depedig o the system capacity ad cofiguratio.

5 HVAC&R Book 9/6/56 2:54 AM Page 5 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 3 THE REFRIGERATION CYCLE The refrigeratio cycle ivolves a umber of physics priciples to covert eergy from oe form to aother, ad to trasfer that eergy from oe poit to aother. Oe of the priciples i the chage of state. Just as it takes eergy to chage ice at 32 degrees fahreheit to water at the same temperature, eergy trasfer is required to chage the state of a refrigerat. The Refrigeratio Cycle The diagram below describes the refrigeratio cycle. Simply stated, electrical eergy i the case of a electrically drive compressor, compresses the refrigerat gas ad causes it to move through the system where it chages from a gas to a liquid ad back. I additio to the chages i gas volume, heat is added or take away at differet poits i the process. DISCHARGE LINE CONDENSER LIQUID LINE FAN/MOTOR RECEIVER BULB HIGH PRESSURE SIDE LOW PRESSURE SIDE EXPANSION VALVE CAPILLARY TUBE BLOWER/MOTOR SUCTION LINE EVAPORATOR REFRIGERATION DIAGRAM

6 HVAC&R Book 9/6/56 2:54 AM Page 6 4 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors Hermetic Compressor s Hermetic Stator/Rotor Electrical eergy is coverted to mechaical eergy by the compressor motor. The compressor draws a refrigerat gas from the evaporator, compresses it ad seds it to the codeser where it is liquefied. Refrigerat gas eterig the codeser is full of heat picked up from the previous cycle plus heat from the compressio cycle. I the codeser, heat is removed from the refrigerat ad it returs to the liquid state. A expasio valve cotrols the flow of refrigerat betwee the codeser ad evaporator. The temperature of the gas eterig the evaporator is lower tha that of the air to be cooled. Heat is removed from the air to be cooled. This heat is absorbed ito the liquid refrigerat causig a chage of state back to a vapor. The cycle cotiues util a thermostat seses that the desired temperature has bee reached ad shuts the system dow. HERMETIC COMPRESSORS The motors ad other compoets of the system operate i a closed system ad must be compatible with each other. Compressors are desigated as hermetic or semi or accessible hermetic depedig o the type of costructio. The word hermetic meas a airtight seal or sealed from outside elemets. Typically, home refrigerator, room air coditioer, home air coditioer, ad small commercially applied compressors are i a welded shell, leadig to the hermetic desigatio. Larger commercial compressors use castigs ad other parts, similar to a automobile egie, which are bolted together ad get the desigatio accessible hermetic.

7 HVAC&R Book 9/6/56 2:54 AM Page 7 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 5 The fuctio of both types is essetially the same. Due to the iitial cost of the larger systems, parts may be salvaged ad used i rebuild or remaufacturer operatios. Hermetic motors are used i hermetic compressors. The sealed system cotais a refrigerat gas ad lubricatig oil. Hermetic motors are fuctioally the same as other types of motors except that the housig, bearigs ad shaft are provided by the compressor maufacturer. These motors are ofte referred to as rotor/stator kits. Sigle phase versios are ofte of the permaet split capacitor (PSC) type which does ot require a startig switch. Systems usig PSC compressor motors ofte have Dual Ca capacitors which are two separate capacitors i oe housig. Oe capacitor is used for the compressor ad oe for the fa motor. A.O. Smith has a selectio of hermetic rotor/stator kits for rebuild ad remaufacture operatios.

8 HVAC&R Book 9/6/56 2:54 AM Page 8 6 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors H VAC & R A p p l i c a t i o B a s i c s HVAC&R APPLICATION BASICS May motors for heatig, vetilatio, air coditioig ad refrigeratio applicatios are desiged special purpose. Kowig the applicatio makes it possible to begi the selectio process at a poit where the possible replacemet will likely be foud. A uderstadig of the applicatio will help assure that the best possible selectio is made. A heat pump performs the same fuctios as a air coditioig system, but cotais a valve w h i ch chages the refrigerat flow ad i effect chages the evaporator ito the codeser ad vice versa. I heat pumps the coils are commoly called the idoor ad outdoor sectios. I the heat pump mode, heat is removed from the idoor coil ad added to idoor air, ad heat is added i the outdoor coil. Heat is preset i all substaces i cludig air ad water util absolute zero is r e a ched at which poit all molecular activity stops. As a example, air at 30 degrees fahreheit may seem cold but it is warmer tha air at 20 degrees fahreheit because it cotais heat. Because they icorporate a chage of state of the refrigerat, it is possible for heat pumps to be more efficiet tha straight resistace heat. This efficiecy is expressed as a measure of watts iput to BTU output. A heat pump s efficiecy decreases as the outside temperature decreases. Electric resistace strip heat is ofte icorporated ito heat pump systems ad is activated whe the heat pump caot meet the demad for heat. Some systems use water istead of air as the heat trasfer medium i the outdoor sectio. The water may be a costat source i a drilled well or a flowig source. Heat pumps are also used to trasfer heat to swimmig pools. I systems usig air as the heat trasfer medium, fas drive by electric motors are used to move air over the evaporator ad codeser coils, facilitatig heat trasfer. Propeller fas are the orm o the outside sectios with blower wheels used idoors.

9 HVAC&R Book 9/6/56 2:54 AM Page 9 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 7 OUTDOOR SECTIONS RESIDENTIAL Eclosed motors are widely used i ew outdoor istallatios. The use of eclosed replacemet motors has rise dramatically i recet years. The service perso may use oe motor for both eclosed ad ope applicatios, reducig ivetory dollars. Eve though a motor is totally eclosed, it still eeds to breathe ad have a place for moisture to drai. Replacemet motors typically have drai holes i both ed frames. A plug is required i the hole o the top of the motor as istalled. If a motor has two plugs, the oe o the bottom should be removed. If oly oe plug is provided, it should be istalled i the top hole. If it is possible for rai or other moisture to accumulate o the motor leads, the leads should be placed to form a drip loop so the moisture will ot drai ito the motor s other compoets. O u t d o o r S e c t i o R e s i d e t i a l FSE1036 Totally Eclosed Outdoor Sleeve Bearig Fa Motor Almost all uits beig built today have 60 degrees celsius (140 degrees fahreheit) fa motors o the hot side of the coil. The ambiet or outside air is pulled through the coil, pickig up additioal heat before it passes over the motor. If the ambiet air is first draw over the motor ad the pushed through the coil, the motor has a lower operatig temperature. If a motor rated 40 degrees celsius (104 degrees fahreheit) is istalled o the hot side of the coil, uisace trippig may occur, especially i high ambiet situatios. Motors used o residetial systems are usually sleeve bearig. Light commercial uits which look just like the residetial uits may have ball bearig outdoor motors. The motor should defiitely be a special ball bearig desig if a speed cotrol device is used. FE1036 Totally Eclosed Outdoor Ball Bearig Fa Motor

10 HVAC&R Book 9/6/56 2:54 AM Page 10 8 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors FS1037S Closed Except Lead Ed Outdoor Sleeve Bearig Fa Motor Motor usage is heavily weighted to six pole (1075 RPM) desigs, followed by eight pole (825 RPM) the four pole ( RPM) uits. Two speed motors are used o some uits to reduce operatig speeds ad costs whe lower ambiet temperatures do ot require as much air flow over the coil. Sice the horsepower required for the fa varies directly as the cube of the speed, a six pole motor caot be used to replace a eight pole motor. Depedig upo the static coditios, the same fa blade may require almost three times the horsepower to ru at 1100 RPM as it does at 825 RPM. Typical moutigs are lug, belly bad or exteded motor thru bolts. Some motors use screws i tapped holes i the mai frame to attach moutig strips or cables. Blocked coils reduce air flow to cool the motor ad ca cause a overload coditio. Lug Mout Adapter Bracket Fas may be statically balaced, but dyamically out of balace due to bet blades. This coditio may lead to bearig failure. The term split system refers to uits with separate idoor ad outdoor sectios coected by refrigerat lie. Packaged uits as the ame implies, have all the compoets i oe place. Room air coditioers, commercial rooftop uits, PTACS (Packaged Termial Air Coditioers) ad mobile home packs are examples of packaged uits. Eve though packs ad commercial uits are etirely outside ad oly ducted to the iside, they have a physical barrier betwee the iside ad outside sectios.

11 HVAC&R Book 9/6/56 2:54 AM Page 11 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 9 Commercial systems whose compoets ad cofiguratios differ from basic home ad commercial packaged ad split systems may also use fractioal horsepower motors i either idoor or outdoor sectios. Fa coil uits with a motor ad blower wheel(s) are used i systems where chilled/heated water or refrigerat is piped through a buildig istead of usig a cetral blower ad duct work. Some chillers use the same type outdoor fas ad motors as rooftop ad packaged uits. Motors used i commercial applicatios such as codesers usually have ball bearig costructio because the loads are heavier. Sleeve bearig motors typically are quieter tha ball bearig motors ad are favored i idoor air movig applicatios. Ball bearig motors may be used to replace sleeve bearig motors but ot vice versa uless you are certai they will meet all applicatio requiremets. FC1106 Pateted Fa Caopy Deluxe Commercial Codeser Fa Motor FY Frame, 3Ø Totally Eclosed Ball Bearig Commercial Codeser Fa Motor FB3056 Base Mouted, 3Ø Outdoor Ball Bearig Codeser Fa Motor BK1072 Commercial Idoor Blower Motor

12 HVAC&R Book 9/6/56 2:54 AM Page Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors Furaces EL2002 Reversible Switch Model Oil Burer Motor FURNACES Furaces geerally use motors for three fuctios: move either heated or cooled air, move fuel, ad provide air for combustio. A specific furace may use more tha oe motor. High efficiecy furaces capture more of the heat of combustio ad use a motor ad blower to provide combustio air ad exhaust flue gases. These motors are commoly called draft iducer motors. C frame ad 3.3 are the most commo motors used i this applicatio. Natural gas ad propae flow through cotrol valves ito the burer area of a furace uder pressure. Oil furaces use a motor ad pump to spray the oil ito the burer area. NEMA stadard M ad N flage motors are commo i oil burer applicatios. Rotatio, horsepower ad flage type are key elemets i motor replacemet. A furace burs substaces such as atural gas, oil, propae, wood ad coal. The heat exchager separates the combustio process from the air i the space beig heated. The motor ad blower circulate air through the heat exchage i a cotiuous cycle util the desired temperature is reached. I most cases, a thermostat ad cotrol circuit is used to operate the cycle. The thermostat cotrols the combustio cycle. The cotrol circuit seses the pleum temperature withi the furace ad sigals the blower motor to start ad stop. This same cotrol circuit also shuts off the combustio process if the blower motor fails to start. Furaces are desiged as hi-boy or up-flow, couterflow or dowflow, low-boy ad horizotal, depedig upo the space i which they are applied. The motor/blower performs the same basic fuctio i all desigs.

13 HVAC&R Book 9/6/56 2:54 AM Page 13 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 11 A squirrel cage blower wheel powered by a direct drive PSC motor is the most commo system ow used i residetial systems because they are efficiet ad compact. Six pole (1075 RPM) multi speed motors are ow the orm. Some eight pole (825 RPM) motors are also used. Belt drive blowers were commo i the past ad may are still i use. Four pole (1725 RPM) motors are the most commo. Some two speed motors are used i cojuctio with electroic air cleaers to provide cotiuous air movemet to reduce drafts. Two speed belt drive motors may have oe of two differet types of iteral switches. Oe type requires a exteral relay to switch from high to low ad low to high speeds. As metioed above, three speed, direct drive, permaet split capacitor, 1075 RPM motors are the most commo. The speeds are available so that the air flow may be tailored to the istallatio. Differet speeds are eeded to move the air depedig upo the static pressure i a system. High speed may be used if the system has air coditioig sice more work is required to move the cold air which is heavier. Medium speed could be used to move air i the heatig mode. FDL1036 High Efficiecy Idoor Blower Motor GF2034 Belt Drive Blower Motor The wire lead from ay speed(s) ot beig used should be isulated separately ad secured so that it does ot cause a short. Furace blower motors are available i both 115 ad 230 volt versios. The 115 volt versios are a throwback to the days whe most homes did ot have 230 volt systems. 230 volt versios are more commo today, especially o electric furaces.

14 HVAC&R Book 9/6/56 2:54 AM Page Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors Electric furaces are a combiatio of wire strips ad a air hadler. The resistace of electricity flowig through the wire strips creates heat. The strips heat air which is circulated by the air hadler. Electric furaces use the same type of air hadlers ad motors as other types of furaces. Some furaces use variable speed motors ru cotiuously. This feature prevets air from becomig stratified ad drafts are reduced. Also, with a electroic air cleaer, the air is costatly beig circulated. Furace motors are ormally of a ope costructio sice they are i a relatively clea, dry ad protected eviromet. DL1036 Stadard Efficiecy Idoor Blower Motor Multi speed direct drive blower motors are ormally desiged to have at least 100 RPM differece betwee speeds. It is ot possible to kow exactly where a give motor will operate o oe of the lower speeds uless a loadig poit is determied. Multiple horsepower ratigs ad speeds show o stock motors are offered as a guide ad are ot exact. It is ot possible to determie speed o a bech with a strobe sice the motor is ot loaded ad will operate close to the same speed o all taps. These motors may trip the overload o a bech test sice they are ot loaded ad will ru faster tha i a applicatio, ad do ot have the ecessary coolig air beig draw over them. Most HVAC&R direct drive motors have o- NEMA stadard moutigs ad shafts ad have frame suffixes of Y or Z. This does ot mea that stock replacemets are ot readily available. FM1036 Fleximout Idoor Blower Motor I may cases, stock motor shafts will eed to be shorteed for specific applicatios. Care must be take to avoid bearig damage.

15 HVAC&R Book 9/6/56 2:54 AM Page 15 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 13 FAN COIL UNITS These uits are a combiatio of a fa, motor ad coil i oe package. While a package cotaiig these compoets i a residetial, coolig oly system could techically be called a fa coil, usually the term refers to commercial ad istitutioal applicatios where chilled or hot water is set through the coil. Fa Coil Uits A wide variety of product cofiguratios is available. The motor ad blower wheel priciples discussed uder the furace sectio also apply here. Oe commo variety is the classroom type which uses a double shaft extesio motor ad two blower wheels whose legth is large compared to the diameter. Usig the small diameter wheels, the desired amout of air may be moved, but the uit does ot protrude too far ito the room. The same type of motor ad blower combiatio is also foud i hotel room uits which look like PTACs. Five ich diameter (42 frame) motors are very popular, but some 48 frame motors are also used. Larger commercial direct drive uits typically utilize ball bearig motors. DBL RPM, 5 Speed Fa Coil Motor, 42 Frame

16 HVAC&R Book 9/6/56 2:54 AM Page Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors Room A i r C o d i t i o e r s Lug Mout Bracket Ed Frame Legth Adapter Kit SA1016 Room Air/PTAC Motor ROOM AIR CONDITIONERS Like PTACs, room uits have all the compoets i oe package. Semi-eclosed motors are commo, but may uits use totally eclosed motors because of the codesate water comig off the coils. Belly bad lug mout kits ad resiliet mout legth adapters are ofte used with replacemet motors. Motors are sigle voltage ad mostly 230V i uits above 9,000 BTU. Some uits have a 277 volt ratig (sometimes marked 265 volt) which is a sigle phase power source from a three phase system. The largest percetage of motors are six pole (1075 RPM) permaet split capacitor desigs. Some shaded pole motors will be foud i the lower BTU uit, but their use has bee decliig due to low efficiecy. Some 60 cycle uits use four pole (1725 RPM) motors which are desiged to operate at a slipped dow speed i the RPM rage. The uit desig requires speeds higher tha 1075, but operatio at true four pole speeds is ot required or desirable from a oise stadpoit. These uits require a direct OEM replacemet. Be aware that motors rated for both 60 ad 50 cycle will have RPMs listed as 1725/1425. The 1425 RPM i this case is at 50 cycle operatio, so this motor is ot a acceptable replacemet for a 60 cycle motor with the RPMs listed as 1425.

17 HVAC&R Book 9/6/56 2:54 AM Page 17 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 15 PTACS Packaged termial air coditioig uits are similar i costructio to room air coditioers. All of the compoets are i oe package. They are commo i hotel/motel rooms, small offices ad apartmets. Strip electric heat is a commo optio. Heat pump versios are available. May differet maufacturer s uits have the same dimesios so they may be used iterchageably i a stadard size wall sleeve. PTACs Some PTAC desigs use two sigle shaft motors (oe for the codeser side ad oe for the blower wheel). Desigs with oe double shaft motor are more commo. Typical blower motors require air over the motor for coolig. The blower motor used o two motor PTACs is o the other side of the uit bulkhead from the blower wheel ad does ot get the same air flow as a furace blower motor. A exact replacemet should be used, or the uit should be tested at the maximum ambiet coditio to isure the motor will ot overheat. AIR CURTAINS Air curtais move a thi, high volume stream of air from top to bottom i a ope doorway to keep the air o the opposite side from mixig. Double shaft motors with blower wheels are commoly used. Air Curtais

18 HVAC&R Book 9/6/56 2:54 AM Page Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors E va p o ra t iv e C o o l e r s V2054 Evaporative Cooler Motor EVAPORATIVE COOLERS These uits which are also referred to as swamp coolers are a alterative to air coditioig i areas where the relative humidity is low eough that the process is effective. They are commo i the desert southwest ad high desert areas such as Salt Lake City ad Dever. Dry air moves over a media pad saturated with water. The moisture lade air is blow through the area to be cooled ad exhausted through vets or slightly ope widows. As the moisture evaporates iside the space, a coolig effect occurs. This is the same as the coolig effect o your ski whe water evaporates after steppig out of the shower. Most motors used i home uits mout i a resiliet base ad have the same rig to rig dimesios. Replacemet motors are ofte sold without bases sice the base does t ormally fail. Sigle ad two speed uits are available. The motors are coected to the blower wheel with a drive belt. Proper belt tesio is 1/2 to 3/4 ich deflectio at the ceter of the belt spa. The motor pulley must be of the type ad size recommeded by the cooler maufacturer. If a adjustable pulley is used, the pulley should be set by a techicia with the ecessary electrical test equipmet. The adjustable pulley allows the load (blower) to ru at a speed compatible with the motor.

19 HVAC&R Book 9/6/56 2:54 AM Page 19 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 17 To set a adjustable pulley: 1. Ope pulley to maximum width ad tesio belt. 2. Read recommeded motor amp ratig at the highest speed. 3. Usig a ammeter, measure the amps at the highest speed. 4. Stop motor, close pulley oe-half tur ad retetio belt. 5. Repeat step 4 util the amp readig meets but does ot exceed the motor s rated amperage. I M P O R TA N T : CAUTION: NOTE: If the amperage exceeds the motor s ratig, the motor will overheat ad stop. The motor will restart automatically after it cools ad the overload resets. Cooler istallatios ot usig duct work will require a smaller diameter pulley tha the same cooler usig duct work. The duct work creates static pressure or resistace to air flow which reduces the motor load ad amp draw. A easy rule to follow is to check the motor amperage while ruig o high speed. It should ot exceed the ameplate amps. Motors with all copper widigs or a combiatio of copper ad alumium widigs are available. With advaces i coectio methods ad widig isulatio, there is little differece i the reliability of either type. May motors are sold at retail with the homeower doig the replacemet.

20 HVAC&R Book 9/6/56 2:54 AM Page Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors Uit Heater s UH1036 Ball Bearig, Mouted Capacitor, Uit Heater Motor Hot Water Circulator s UNIT HEATERS Uit heaters are the ductless furaces that hag from the ceiligs of factories, warehouses ad garages. The motor ad propeller fa are usually visible. Eclosed motors are commo due to the ofte dusty eviromet. Motors may be either belt drive or more commoly, direct drive. The direct drive are usually 42 or 48 frame desigs usig thru bolt/exteded stud or resiliet rig mouts. Replacemets are available with ad without bases, ad PSC types ofte have the capacitor mouted o the motor. HOT WATER CIRCULATORS Heatig systems that have hot water boilers use a motor drive pump to circulate the water. These motors have special shaft extesios ad moutig brackets. OBG2002 Whole-House Vetilator s WHOLE - HOUSE VENTILATORS The uits ormally mout i the ceilig, pullig air i through ope widows ad exhaustig it to the attic where it exits through vets. May older uits used ope drip proof motors, but most ew desigs have totally eclosed motors or some type of metal shield to reduce the fire hazard. Belt drive motors are geerally four pole (1725 RPM), ad direct drive are mostly six pole (1075 RPM).

21 HVAC&R Book 9/6/56 2:54 AM Page 21 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 19 PEDESTAL FANS Pedestal fa motors are used to circulate air with a propeller type blade mouted directly o the motor shaft. Pedestal Fas Some motors are base mouted, but more commo is the yoke mout which is a bracket welded or bolted to the motor frame. Exteded motor thru bolts for moutig a fa guard are commo. MISCELLANEOUS May applicatios usig small (1/8 HP or less) motors do ot have replacemet motors available sice the uit cost is low. Examples iclude ceilig or paddle fas ad widow ad box fas. Other applicatios such as humidifiers, hood exhaust fas, bathroom fas, refrigerators, small room air coditioers ad furace draft iducers may use 3.3 diameter motors. Four pole shaded pole ad two pole permaet split capacitor motor with thru bolt moutigs are commo. YA2020 Yoke Mout M i s c e l l a e o u s AO1154, 3.3 AO120, 3.3

22 HVAC&R Book 9/6/56 2:54 AM Page Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors Fa Blade ad Blo wer Wheel Basics FAN BLADE AND BLOWER WHEEL BASICS The horsepower eeded to drive a propeller fa or blower wheel varies directly with the cube of the speed if the static pressure or discharge area does ot chage. The propeller fa eeds more horsepower if the discharge area is reduced (assumig speed does ot chage) ad the blower wheel eeds less. The reverse of these priciples also apply. The priciples above have great importace for istalled motors,ad whe selectig a replacemet motor. As examples: Blocked or dirty coils o a outdoor uit reduce air flow ad put more load o the fa motor, possibly causig the thermal overload to trip. If a 1075 RPM motor is used i place of a 825 RPM motor, the loadig is too high ad the motor will ot operate. It may be impossible to determie if a replacemet furace motor is properly loaded if the access pael(s) is ot i place - static coditios have chaged. ROTATION The selectio of a replacemet motor obviously requires oe that turs i the proper directio for the applicatio. May sigle phase replacemet motors are dual rotatio. Some product groups have motors that are idetical except for rotatio ad other groups or specific motors have the rotatio which matches the origial OEM offerig.

23 HVAC&R Book 9/6/56 2:54 AM Page 23 Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors 21 Rotatio o some double shaft motors may effectively be chaged by rotatig the motor 180. The rotatio of ay three phase motor is reversed by switchig ay two of the three lie leads. Rotatio There are several ways to idetify the rotatio of a motor i the applicatio. 1. Look at the motor ameplate, coectio diagram ad physical coectio. 2. If the motor has ot failed completely ad is still operable, observe the rotatio ad mark the ed frame or mai frame. 3. Look for a rotatio arrow o a propeller fa ad blower wheel or housig. 4. Determie which way the air must flow i the uit ad the look at the propeller or wheel ad housig. FORWARD CURVED BLOWER WHEEL SIDE VIEW WEDGE ACTION LEADING EDGE AIR OUT CUPPED SIDE OF BLADE LEADING EDGE LEADING EDGE SIDE VIEW MOTOR TOPVIEW Diagram A Diagram B

24 HVAC&R Book 9/6/56 2:54 AM Page Heatig, Vetilatig, Air Coditioig, & Refrigeratio Motors The propeller fa moves air by the wedge actio of the blades. If the blades are cupped, air will move away from the cupped side. If the blades are flat (ormally they are ot) as i Diagram C, air will move i either directio depedig upo motor rotatio. The lower edge of the fa blade, as related to the wedge actio, is the leadig edge just as the thiest part of a wedge goes i first to split a log. Blower wheels are cetrifugal fas. As with ay cetrifugal actio, the speed is greatest at the outermost portio of the device, i this case, the wheel s outside diameter. The fis may be slated i the directio of the air flow, but this is ot always the case. If the motor ad wheel are ot together, it will be ecessary to determie o which side the motor mouts. If the motor applied to the blower wheel i Diagram B ra i the opposite directio, air would move i the same directio as show but ot efficietly. Replacemet motors ofte have rotatio letters such as CWLE (clockwise, lookig at the lead ed) or CCWLE. The letters CWPE (clockwise, lookig at the pulley or shaft extesio ed) are also used o some motors. Drawig a simple sketch of the motor, fa ad uit ofte helps i the orietatio process.

25 HVAC&R Book 9/6/56 2:54 AM Page 25 Geeral Purpose Motors 23 G e e r al Purpose Motors Geeral purpose motors as their desigatio idicates may be used i a variety of applicatios. The desiger of a piece of equipmet ca tailor the load so that a geeral purpose motor may be applied. The system cosistig of the motor ad the drive load ofte has a ratig which idicates the stadard ad maximum amout of work it ca do. The ratigs may or may ot iclude a overload or safety factor. As a example, a hydraulic pump system used to power a lift has a limit to the amout of pressure it ca develop ad trasfer to other system compoets. If the lift is rated for 10,000 pouds, ad the load is 20,000 pouds, a relief valve must ope or the weakest lik i the system will fail. The replacemet motor should be equivalet to the origial desig. A weaker motor would ot allow the system to operate as desiged. Ad, a stroger motor may create a usafe coditio. I the case of a table saw, the load varies depedig upo the type of wood beig cut, ad the speed of the cut. A 1/2 horsepower motor may be suitable to start ad ru the saw ad cut pie, but it may be okay to apply a 1-1/2 horsepower motor to the same saw i order to cut oak. EB3104 3Ø Eclosed Idustrial Duty RB1074 Capacitor Start Resiliet Base The importat poit here is to select a replacemet motor equivalet to the origial uless you have eough kowledge of the applicatio to be certai that a stroger, weaker or differet type of replacemet motor is acceptable ad safe. POWER TOOLS Geeral Purpose NEMA 48 ad 56 frame, 2 pole ad 4 pole motors are commo o cotractor ad home type tools such as drill presses, joiter plaers ad table saws. Motors should have maual overloads or o overload. There are o exceptios to this rule - EVER! If a motor had a automatic overload ad tripped, it could start uexpectedly after coolig ad cause ijury. Pow er Tools The iformatio ad procedures described i the replacemet module of this series will assist i determiig that you are dealig with a geeral purpose motor. Catalog listigs of geeral purpose motors are orgaized by physical ad electrical characteristics to aid i the selectio process.

26 HVAC&R Book 9/6/56 2:54 AM Page Special Purpose Motors Special Pur p o s e M o t o r s Followig are some examples of special purpose motor applicatios. Keep i mid that the origial equipmet was tested to isure that the motor would operate safely ad properly uder the coditios for which it was desiged. Modificatio or misapplicatio may be usafe ad detrimetal to the motor or equipmet. There are literally thousads of applicatios usig geeral purpose type motors with mechaical ad electrical variatios. Each of these variatios must be evaluated to determie if a stock motor will work, possibly with modificatios, or if a replacemet must be obtaied from the OEM. Glass Washer s GLASS WASHERS Sump pump motors are ofte used o glass washers used i bars. This use is ot codoed by motor maufacturers. A motor desigated for glass washer duty should be used ad wirig must be doe i accordace with all applicable codes ad iclude a groud fault device.

27 HVAC&R Book 9/6/56 2:54 AM Page 27 Special Purpose Motors 25 GARAGE DOOR OPENER MOTORS COMMERCIAL DOOR OPENER MOTORS GATE MOTORS I geeral, these motors are excellet examples of good desig ad applicatio ad provide testimoy to the reliability of today s motor productio processes. If a motor does have a defect that will lead to failure, that failure is most likely to occur early i the warraty period at which time the etire uit is replaced. If a motor fails at some later time, it is usually less expesive to replace the etire uit. Commercial uits utilize reversig switches ad are usually serviced by door firms who get their motors from the origial equipmet maufacturers. AIR COMPRESSORS Motors used i air compressor applicatios may be belt drive or direct drive. O direct drive uits, the compressor housig usually provides support for the shaft extesio ed bearig. As such, these are partial motors ad replacemets are ot available i a stock motor lie. Belt drive compressors use a more covetioal motor with a base ad sigle shaft extesio. Horsepower, service factor ad RPMs are the keys to idetifyig a replacemet motor. The horsepower ad CFM (cubic feet per miute of air) characteristics of compressors are ofte advertised. Commercial/idustrial compressors use NEMA frame motors with idetifiable service factors. Hobby compressors ofte have motors with the service factor marked as special. Special meas less tha oe. Garage Door Opeer Motors/ Commercial Door Opeer Motors/ Gate Motor s Air Compressor s CP1502M Also, keep i mid that there is a rage of performace withi the same horsepower ratig, depedig upo motor type ad maufacturer. Check the replacemet motor amps after istallatio to verify selectio.

28 HVAC&R Book 9/6/56 2:54 AM Page Special Purpose Motors Carboator Pump Sump Pump Sewage/ Effluet Pumps CB2024A SP2030A Some electric compressor horsepower ratigs have bee determied by comparig the CFM to a compressor usig a gasolie egie. Sice the gasolie egies are ot as efficiet as electric motors, a compressor may be called five horsepower eve though the motor does ot actually develop five horsepower. Amps are importat i the fial motor selectio sice they determie the required circuit capacity to which the compressor will be coected. A replacemet motor with the equivalet horsepower ad service factor may ot be acceptable due to the efficiecy of the origial motor. Some motors are capacitor start ad ru, with more tha oe ru capacitor. A replacemet capacitor start oly motor may have ruig amps which are too high. CARBONATOR PUMP These motors are used i beverage dispesig systems. The shaft extesio is special ad desiged to mate to the pump. Carboator pump motors are also used i hydraulic pump applicatios. Eve though the moutig is special, it is uiform amog motor maufacturers. SUMP PUMP Motors used o sump pumps may be of the pedestal type ad mouted o the ed of a support colum (1-1/2 ID or 1-3/4 OD), or the immersible type. Most smaller immersible types are ot repairable. Key factors i selectig a pedestal type replacemet are horsepower, service factor, eclosure, protector/overload ad hub dimesios. SEWAGE/EFFLUENT PUMPS Motors used i these applicatios are sealed i a housig ad may or may ot be repaired or replaced by a qualified service perso. The electrical desigs are geerally similar to stock type motors, but their moutig is special. The origial equipmet maufacturer should be cotacted regardig replacemet.

29 HVAC&R Book 9/6/56 2:54 AM Page 29 Special Purpose Motors 27 EXPLOSION PROOF APPLICATIONS Motors used i hazardous eviromets such as flour mills ad gas pumpig applicatios require special costructio features so that a short or spark i the motor will ot igite flammable liquids, vapors or dust that may be preset. The desig, maufacturig ad applicatio of these motors is subject to Uderwriter s Laboratory rules ad may other local ad atioal codes. Explosio Proof Applicatios May OEM gasolie pump motors have special moutig flages ad o/off switches ad are ot replaceable by stock type motors. Due to the liability potetial, recommedatios should ot be made as to the applicatio of these motors. The perso makig the purchase should have the traiig ad qualificatios to kow the exact motor required. POULTRY DUTY FAN MOTORS Commercial poultry house fas use both alumium ad steel propeller blades, direct or belt drive, maily by base mouted motors. The desigs are usually totally eclosed, air over (TEAO), meaig they rely o the blade s air movemet for coolig air. XP1070 Poultry Duty Fa Motor s It is essetial to the chicke s survival that hot, stale air is exhausted. TRANSFORMER COOLING FAN MOTORS These are very specialized direct drive propeller fa motors used to cool large electric utility trasformers. They are sometimes referred to as fi fa motors. The desig is very robust, employig ball bearigs ad stailess steel shafts. Replacemet motors are ormally secured through the origial equipmet chael. Tr asformer Coolig Fa Motor s

30 HVAC&R Book 9/6/56 2:54 AM Page Motor Troubleshootig Guide WARNING! This is ot a guide for the do-it-yourselfer. M o t o r Tro u b l e s h o o t i g G u i d e Some procedures require special tools ad specific product kowledge which is beyod the scope of this module. These tips ad suggestios are offered for persos with proper qualificatios ad ecessary test equipmet, ad as iformatio of geeral iterest to persos i the replacemet motor distributio chael. There is ot a sigle listig of motor troubleshootig procedures to be followed i a give order. The procedures will also differ for ew ad existig istallatios ad motors that are beig bech checked. As with aythig dealig with electricity, persoal safety is the prime cocer. Bech Chec k BENCH CHECK First, cosider what symptom lead to the motor s removal from service. Examples: It was oisy, it would t start whe the power was applied, it tripped the breaker, it rus for several miutes the shuts off, it just hums whe power is applied, smoke came out whe it was tured o.

31 HVAC&R Book 9/6/56 2:54 AM Page 31 Motor Troubleshootig Guide 29 Kowig why a motor failed may be importat i selectig the proper replacemet motor, ad isurig a good service life. Try to determie the age of the istallatio ad if the motor is the origial. If the motor is a replacemet, how log has it bee i service? Does it appear to have bee properly istalled? What is the duty cycle or service period? Havig some idicatio of the problem ofte idicates items to check first. A bech check is usually a cofirmatio of a suspected problem. The type of motor ad its costructio will dictate which items may be checked without disassembly. The followig tips ad suggestios are by o meas complete, but offer some of the basics relatig to a motor ad its applicatio. Other modules cover some subjects i more detail, ad specific kowledge from other sources may be eeded. To the degree possible, check the same areas i the applicatio as would be doe i a bech test. Is there ay evidece of water damage? Does the shaft tur freely? O sleeve bearig motors, check ed play ( ormal). Lack of ed play could cause motor to bid whe hot.

32 HVAC&R Book 9/6/56 2:54 AM Page Motor Troubleshootig Guide O belt drive loads with sleeve bearig motors, check to see that the motor is orieted properly i relatio to the bearig s oil wick widow. Excess heat is the eemy of a motor. If the motor has bee operatig properly, has aythig chaged? Is the voltage too high or too low? Is the ambiet too high for the motor? Are iteral or exteral fas clea ad itact? Has foreig material gotte ito the motor? Is ormal air flow aroud the motor blocked, causig recirculatio? Is there ay evidece of physical damage or overheatig? I applicatios such as direct drive furace blowers, the motor eeds system air for coolig. There is ot a geeral rule of thumb, but use of a replacemet motor sigificatly stroger tha the origial may result i overheatig. Speed will be up ad the system may ot provide eough air for coolig. Select a close replacemet ad check amps after istallatio. Check widigs for cotiuity. Check for cotiuity betwee motor leads or termial board ad frame as idicatio of short to groud. Check capacitor if capacitor start ad/or ru. Check the overload if accessible. If a sigle phase motor with a mechaical start switch starts but does ot come up to speed, check the switch for proper operatio. If this same type motor just hums ad does ot start, check the switch ad start widig.

33 HVAC&R Book 9/6/56 2:54 AM Page 33 Motor Troubleshootig Guide 31 If motor appears to ru okay it may be okay. Or, it may have a iteral problem such as loose or plugged coolig fa. It is possible for a widig coil to be shorted oto itself without idicatig a ope coditio. The motor would be weak ad probably overheat uder load. If the motor has a termial board, coectios could be loose causig itermittet operatio. Check for phase imbalace o three phase systems. Checkig a motor i its applicatio is the oly practical method for most people to determie performace uder load. If the motor is defective, the applicatio provides may clues to help determie the cause. Did the motor fail due to a defect or old age. Or, was its failure hasteed by the applicatio or eviromet? The applicatio is the oly place a attempt may be made to check voltage. O permaetly istalled equipmet, the voltage may vary depedig upo the total system load. It ca also vary with the total load o the power compay grid. Mobile equipmet such as retal uits are ofte abused through the use of iadequate extesio cords or udersized geerators. Was the motor misapplied or has the applicatio load chage? Dirty or blocked coils may overload a codeser motor. Reduced static pressure may overload a motor drivig a blower wheel. Is the belt drive load free to tur, ad i proper operatig coditio?

34 HVAC&R Book 9/6/56 2:54 AM Page Motor Troubleshootig Guide Most motor applicatios have service mauals whose procedures, especially those ivolvig safety, should be followed. Withi the scope of this discussio, the assumptio must be made that the procedures have bee followed to the poit where the motor is suspected, ad proper voltage (ameplate as coected +10%) is available to the motor. I additio to the electrical hazard, a applied motor could be very hot if a start was attempted durig other test procedures. Always groud motor ad secure so startig torque will ot cause it to move i bech test. Always use the proper tools (ot a hammer) to remove fas ad pulleys from a motor that is to be reistalled. Likewise, ever poud aythig oto a motor shaft. A ball bearig ca easily become brielled or work hardeed leadig to evetual failure. I a ew istallatio of ew equipmet that does ot start, follow the established procedures to the poit where a motor check is recommeded. The procedure is basically the same for a replacemet motor o a existig applicatio except the case where the motor bured out as soo as the power was applied. I this case, the motor was probably hooked up wrog. O a replacemet motor there is slight possibility that the wrog ameplate was applied. Does the coectio iformatio physically match the motor? Are other motors with the same part umber but differet date codes the same? Specific resistace values from the maufacturer may be required for positive cofirmatio.

35 HVAC&R Book 9/6/56 2:54 AM Page 35 NOTES: NOTICE: The iformatio cotaied i this booklet is geeral i ature ad is draw from sources believed to be reliable. It is iteded for geeral iformatio purposes oly. The descriptios i this booklet may ot apply to a particular motor or a particular applicatio. No warraties are iteded to be created by this iformatio.

36 HVAC&R Book 9/6/56 2:54 AM Page NORTH FOURTH STREET TIPP CITY, OH (937) FAX: (937) A.O. Smith Corporatio 1/03 Bulleti #3200