AO Smith Water Pump Pool Spa Motor User Manual

Installation  
Maintenance  
Service  
Troubleshooting  
CENTURY®  
POOL & SPA MOTOR  
MANUAL  
INTRODUCTION  
elcome to A.O. Smith’s line of Century®  
Motors. This pocket manual is designed for  
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one purpose — to make it simple for you to  
install, maintain and troubleshoot Century pool and  
spa motors. Contrary to what you may be thinking just  
now, your last name doesn’t have to be Edison in order to  
properly service the motors shown in the following pages.  
All you need are a few basic tools and some helpful hints;  
the kind that appear throughout this  
booklet.  
We’ve included all the information we think you’ll  
need to repair the most common pump motor problems  
encounteerd out in the field. This easy to read manual con-  
tains great illustrations and diagrams for quick  
reference. Assisting your customers is your job. Helping  
you do that with minimum delay is our job; that’s why  
we’ve prepared this informative manual.  
1
Replacements for every brand. Every now and then  
you probably come across a motor that’s beyond repair.  
When you do, remember that A.O. Smith manufactures  
replacement pool and spa motors for practically every  
brand you’ll ever encounter in the field. So save yourself  
some time and effort and just ask for Century first — at  
any A.O. Smith distributor or dealer. Century motors are as  
rugged as any you’ll find, but keep in mind that all motors  
need service and maintenance at one time or another.  
Safety first. Remember, before you begin to work on  
any electrical appliance be sure to TURN OFF THE  
POWER. The only time you’ll need the power on is  
when you check motor voltage and amperage. If you over-  
look this important guideline, someday you could unex-  
pectedly get a real charge out of your work! Always play it  
safe — double-check to be certain that the power is off  
before you start to work on a pool or spa motor.  
If you have any suggestions or would like more  
information about a particular subject, please write  
or call:  
A.O. Smith  
531 North Fourth Street  
Tipp City, OH 45371  
800-543-9450  
2
TABLE OF CONTENTS  
Century Pump Motors ..................................................5....  
Design Features...........................................................7.....  
Nameplate Information................................................9....  
Installation  
Heat..........................................................................13  
Moisture...................................................................14  
Power Source..........................................................14  
Altitude.....................................................................14  
Mounting..................................................................14  
Electrical Connections .............................................15  
Grounding................................................................15  
Wire Size..................................................................15  
Wire Selection Guide.....................................................16  
Tools................................................................................17  
Maintenance  
Moisture...................................................................17  
Cooling.....................................................................18  
Seasonal...................................................................18  
Cleaning...................................................................18  
Lubrication...............................................................18  
3
Motor Troubleshooting  
Motor Fails To Start (makes no sound)..................19  
Motor Fails To Start (hums, tries to start,  
blows fuse or trips breaker)....................................20  
Motor Starts But Shuts Down  
(overload problem)..................................................21  
Noisy Motor.....................................................................21  
Motor Hot, Smoking Or Cycling ....................................22  
Information Needed For Motor Replacement..............23  
Troubleshooting A Capacitor .........................................23  
Best Way To Use A Volt-Ammeter.................................24  
How To Replace Bearings..............................................24  
Service............................................................................27  
Wiring Diagrams’ Table of Contents.............................28  
Wiring Diagrams.......................................................29-54  
Date of Manufacture Table............................................55  
4
CENTURY® CENTURION &  
®
Centurion , C-flange  
Switchless “1081” Motor  
• Standard Efficiency  
• E-Plus, High Efficiency  
1
• ⁄2 – 5 Hp  
• No Switch, No Governor  
• Single phase or three phase  
• Suitable for operation at 50 Hz,  
1.0 service factor  
• Aluminum or cast iron NEMA “C” mounting brackets  
True NEMA 56-frame  
• Keyed or threaded shaft  
• UL standard “1081” approvable  
• Full-rated and Up-rated  
• 50° C Ambient  
• Available as a Century two-speed motor  
®
Centurion SE, C-flange  
Switchless “1081” Motor  
1
• ⁄2 – 5 Hp  
• Standard Efficiency  
• Single phase  
• Aluminum NEMA “C”  
mounting brackets  
• 50° C Ambient  
True NEMA 56-frame  
• Keyed or threaded shaft  
• UL Standard “1081” approvable  
• Full-rated and Up-rated  
• 303 stainless steel shaft  
5
E-PLUS® MOTORS  
®
Centurion , Square Flange  
Switchless “1081” Motor  
• Standard Efficiency  
• E-Plus, High Efficiency  
1
• ⁄2 – 5 Hp  
• No Switch, No Governor  
• 303 stainless steel  
threaded shaft  
• Suitable for operation  
at 50 Hz, 1.0 service factor  
• Single or three phase  
True NEMA 56-frame  
• UL standard “1081” approvable  
• Full-rated and Up-rated  
• 50° C Ambient  
• Available as a  
Century two-speed motor  
®,  
Neptune C & Square Flange  
• Standard Efficiency  
• High Efficiency  
1
• ⁄2 – 3 Hp  
• Advanced Switch Technology  
• 48 frame shell diameter  
• 303 stainless steel threaded shaft  
• UL standard “1081” approvable  
• Full-rated and Up-rated  
• 50° C Ambient  
6
FLEX-48™  
POOL AND SPA MOTORS  
Flex-48™ Single-Speed Motors, Thru-Bolt Mount  
Suitable for jetted tubs and above-ground pools and spas.  
1
• ⁄2 - 3 Hp  
• 56-frame conversion base  
• 3-12” shaft height  
3
• ⁄8” threaded shaft  
• Auto-reset overload  
protection  
• 1.0 service factor  
Flex-48™ Two-Speed Low Amp Start & Run Motors  
For Spas and above-ground pools, thru-bolt mount.  
3
• ⁄4 - 3 Hp  
• 56-frame conversion base  
• 3-12” shaft height  
3
• ⁄8” threaded shaft  
• Auto-reset overload  
protection  
• 1.0 service factor  
CENTURION®  
DESIGN FEATURES  
entury pool and spa pump motors are tailored for  
demanding pool loads and environments. Check these  
C
outstanding features:  
1. Full-rated 56-Frame diameter gives greater thermal  
capacity, better durability with industrial quality construction.  
7
CENTURION®  
DESIGN FEATURES  
2.All Threaded shafts are 303 stainless steel for superior  
corrosion resistance. Keyed shaft of carbon steel is iron  
phosphate treated to prevent rust. Stainless steel shafts  
provided on cast iron C-flange, keyed shaft product.  
3.Double-sealed high thrust bearings protect against dirt and  
moisture. Factory lubricated, never need regreasing.  
4. Special aluminum alloy brackets or cast iron NEMA “C”  
brackets resist corrosion from pool chemicals.  
5.Drive-end bearing locked to limit shaft endplay.  
6.Continuous rated run capacitor provides high running  
efficiency and better starting performance in low voltage  
situations.  
7. Easy connect terminal board is designed with screw post  
line terminals. All you need is a screwdriver for fast and  
easy installation wiring.  
8.Moisture resistant, Class B insulated windings for extra  
protection against moisture, high ambient temperatures,  
salt spray, chemicals, diatomaceous earth, sand, dirt,  
insects, etc.  
9.Motors designed to meet UL Standard #1081, protects  
internal components from rain, dirt and chemicals.  
10.Class B automatic reset overload protector suitable for  
high ambient temperatures. Prevents nuisance tripping in  
hot areas.  
8
NAMEPLATE INFORMATION  
hen you need information about the motor  
you’re servicing, you’ll always be able to find it  
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printed on the motor nameplate. On A.O. Smith  
motors the nameplate is usually found on the side of the  
motor, below the capacitor. Shown below is a sample  
pool motor identification nameplate. As you read the  
nameplate, refer to the guide so that you understand  
the meaning of each item that the manufacturer  
provides about its motor. Remember also that your  
dealer or distributor can give you valuable information  
that can help you to make the correct selection of a  
replacement motor.  
9
1.CAT NO (Catalog Number): This number indicates  
that the motor is a stock rating, readily available  
from standard inventory as a replacement pool  
motor.  
2.PART: This identifies the motor’s specific design  
by part number.  
3.FR (Frame): The frame identifies the mounting  
and shaft configuration. It doesn’t indicate the  
diameter of the shell. A.O. Smith’s line of Centurion  
and Centurion SE motors have a “56 frame” shell  
and are 6.5 inches in diameter. Neptune and  
Flex-48 products are designed in a 48 frame shell  
and are 5.6 inches in diameter. Common terms you’ll  
see on the nameplate are “56J,” “56C” and “56Y.”  
The 56J is always a C-flange, threaded-shaft motor;  
the 56C is always a C-flange, keyed-shaft motor.  
Motor-frame mountings with the “Y” identification  
10  
NAMEPLATEINFORMATION  
identify motors not specified by NEMA mounting  
and shaft standards.  
4.TYPE: The electrical design of the motor is shown  
by its type. A.O. Smith uses “CX” to identify its  
switchless design. Other codes include “CS” for  
capacitor-start, “S P” for split-phase and “CP” for  
capacitor start / capacitor run. Be sure to check with  
the dealer or distributor, because motor type codes  
may vary among manufacturers.  
5.HP (Horsepower): Conventional unit of measure-  
ment for power. One horsepower equals 746 watts.  
6.RPM (Revolutions Per Minute): RPM states the  
rotational speed of the shaft at rated load.  
7.HZ (Hertz): Measurement of frequency, equaling  
cycles per second of alternating current.  
8.PH (Phase): Denotes a single- or three-phase  
motor.  
9.SF (Service Factor): Service factor is the measure  
of the reserve margin built into a motor. Motors  
rated over 1.0 SF allow the motor to operate at a  
higher margin than designated by the horsepower  
rating. Maximum horsepower capability equals  
horsepower multiplied by the SF.  
(continuous operation).  
10.VOLTS: Voltage is the required electrical potential  
applied to the motor, the force that produces current  
in an electrical conductor.  
11.AMPS: Electrical current flowing through the  
conductors. On pool motors, the amperage is  
maximum or service factor amps that result at  
11  
maximum horsepower (Hp x SF).  
12.TIME: Time indicates the duty cycle of the motor.  
Pool and spa motors are generally rated for  
continuous duty.  
13.AMB (Ambient Temperature): The maximum  
ambient (surrounding) temperature in which the  
motor is designed to operate. This temperature  
is shown in Celsius rather than Fahrenheit.  
14.INSUL CLASS (Insulation Classification):  
The temperature rating of insulation used in the  
construction of the motor. Most pool and spa  
motors use a Class “B” insulation.  
15.ENCL (Enclosure): Common enclosures used  
include DP (dripproof) and TEFC (totally enclosed  
fan cooled). Most pool and spa motors feature a  
dripproof design, with “1081” features.  
16.CODE: The NEMA code letter specifies locked  
rotor kVA per Hp (volts multiplied by locked rotor  
amps, divided by 1000 times rated HP).  
17.SERIAL: The serial indicates the date of  
manufacture, which often appears as year/month  
combinations. Serial code information for each  
pool and spa motor can be found in guides and  
bulletins provided by the manufacturer (See p.55).  
18.VOLTAGE DIAGRAM: This diagram provides  
information on the correct electrical connections  
to ensure proper operation of the motor.  
19.WARNING:The warning at the bottom of the label  
re-emphasizes that voltage can be hazardous.  
Always TURN THE POWER OFF before working on  
a pool or spa motor.  
12  
INSTALLATION  
The number one enemy of a motor is  
heat. Overheating always results  
H E AT  
whenever there is a lack of clean, continually-circulating  
air for a motor. Heat can damage a motor’s windings,  
insulation, bearing lubricant and run capacitor. In short,  
heat can quickly decrease the service life of a motor.  
Remember, proper ventilation is always a crucial consid-  
eration when installing a motor.  
If at all possible, install a motor in a location that is  
free of dirt, dust or airborne debris, such as leaves.  
Indoors is best, but not in areas with high humidity,  
such as a laundry room or shower area. If the motor is  
installed outdoors, try to choose a shady spot that’s pro-  
tected from leaves and grass clippings. If you cover the  
motor to protect it from possible debris or water, be  
sure to leave enough space between the cover and the  
motor for adequate ventilation.  
A.O. Smith single phase pool and spa motors  
feature a thermal overload protector that will shut down  
the motor if it overheats. As the windings begin to cool  
down, the overload protector will automatically re-start  
the motor. Blocked ventilation or an overload condition  
can cause the motor to shutdown on a repeated basis.  
If a problem cannot be located or if tripping continues  
after a noted problem is corrected, contact the original  
equipment contractor for a recommendation on  
matching motor horsepower to the pump.  
TIP: In situations where the ambient temperature is  
exceptionally hot, utilizing an E-Plus (High Efficiency)  
motor in place of a standard efficient motor can  
prevent the overload protector from nuisance tripping.  
13  
Century and Neptune  
motors have superior  
M O I S T U R E  
resistance to moisture, but you should avoid placing  
the motor where it can be splashed. Avoid installing the  
motor in low spots where it could collect water and be  
flooded. In fact, it’s probably a good idea to elevate the  
motor at least two inches off the ground.  
Before you turn  
P OW E R S O U R C E  
the motor on,  
check to see that the line voltage, phase and frequency  
match the specifications shown on the motor name-  
plate. Current capacity must be adequate enough to  
maintain rated voltage at the motor terminals under  
all conditions. If it’s too high, contact the local utility.  
If it’s too low check for overloaded circuits, loose  
connections or wire of the wrong gauge (see wire  
selection guide).  
Generally, motors will  
A LT I T U D E  
run hotter with increasing  
altitudes. For installations more than 3,300 feet above sea  
level, it’s advisable to use a motor with the next  
larger horsepower rating than the one recommended  
for that application at sea level or use a A.O. Smith E-Plus  
(High Efficiency) motor of the same rating when available.  
Fastening the pump and  
M O U N T I N G  
motor assembly securely  
to a foundation or base will prevent vibration, loosening,  
and future misalignment. Make sure that the motor and  
pump assembly rotate freely before starting the motor.  
14  
The task of wiring  
your motor is fairly  
simple. The wiring  
E L E C T R I C A L  
C O N N E C T I O N S  
diagrams shown on the following pages are color-coded  
for easy reading. The appropriate part number is listed  
in each illustration, just in case you need to order the  
complete wiring diagram or connection label sticker  
for your motor. Make sure the connections are tight  
to prevent failure or overheating. If you do find loose  
connections, check for excessive vibration.  
Without proper grounding  
G R O U N D I N G  
of a motor, serious elec-  
tric shock is possible. A grounding conductor should  
always be connected under the green grounding screw,  
which is located within the terminal compartment of the  
motor. National and local electrical codes are important,  
and should be adhered to when working  
on a motor.  
Incorrect voltage at the  
W I R E S I Z E  
motor terminals can cause  
the motor to overheat. It’s a good idea to check the  
electrical supply wires to confirm that they are sufficient  
to handle the motor load. For example, if you’re using  
a 1-12 Hp motor at 115 volts over a distance of 150 feet,  
use #8 wire. If the motor can be installed to  
operate on 230 volts, #12 wire should be sufficient  
for a 150 foot distance.  
15  
WIRE SELECTION GUIDE  
THE SIZES SHOWN IN THE FOLLOWING WIRE SELECTION  
CHARTS ARE RECOMMENDATIONS ONLY. ALWAYS FOLLOW  
LOCAL AND NATIONAL ELECTRIC CODES.  
115V Power Line  
Maximum Distance from Fuse Box to Motor  
Motor Hp  
50’  
14  
14  
12  
12  
10  
10  
100’  
14  
12  
12  
10  
10  
8
150’  
12  
10  
10  
8
8
6
200’  
12  
10  
8
8
6
1
3
2
1
3
4
1
1-12  
2
6
3
230V Power Line  
Maximum Distance from Fuse Box to Motor  
Motor Hp  
50’  
14  
14  
14  
14  
14  
14  
12  
100’  
14  
14  
14  
14  
14  
14  
12  
150’  
14  
14  
14  
14  
12  
12  
10  
200’  
14  
14  
14  
12  
12  
10  
10  
1
3
1
2
3
4
1
1-12  
2
3
Guides for copper conductors only.  
16  
TOOLS  
ith a few simple tools, you’ll be ready for just  
about any kind of basic motor service. To make  
W
your job easier when installing or servicing a  
pool or spa motor, make sure that you have these tools  
in your toolbox before you begin working...  
Standard screwdriver  
Wide blade screwdriver  
12” open end wrench  
Rubber mallet  
Clamp-on ammeter/voltmeter  
Ammeter  
516” nut driver  
Needle-nose pliers  
Tape for marking  
MAINTENANCE  
.O. Smith pool and spa pump motors are built  
tough, to run day after day without being serviced.  
A
When service is necessary, serviceable parts usu-  
ally can be accessed quite easily. For example, capaci-  
tors are externally mounted, and single-phase motors  
have screw-type connectors for quick reconnection in  
the field.  
Water leaks from pump  
M O I S T U R E  
seals or pipe joints should  
be repaired to prevent failure of bearings and insulation.  
DO NOT splash or spray the motor. Mount the motor  
away from low spots and damp areas, and take mea-  
sures to protect it from windblown rain.  
17  
MAINTENANCE  
An operating motor is usually  
too hot to touch by hand.  
C O O L I N G  
It should be located away from direct sunlight and other  
heat sources, such as laundry appliances and water  
heaters. Provide for ample air circulation around the  
motor. Clean the air inlets as required, making sure that  
the POWER IS OFF first.  
Whenever the motor must  
S E A S O N A L  
be shut down for extended  
periods, be sure all surfaces, vents and interiors are dry  
to prevent rust. If the motor is kept outdoors, cover it  
to prevent debris such as blowing leaves, dirt and snow  
from clogging the inlets. DO NOT SEAL THE MOTOR  
IN PLASTIC OR OTHER AIR-TIGHT WRAPPINGS,  
because condensation may form on the inside,  
damaging bearings and insulation.  
In general, the inside of  
C L E A N I N G  
the motor should not need  
cleaning if proper safeguards are made against contami-  
nation by dirt, lint or sand. If you want to clean the  
outside, simply use a damp cloth. Don’t spray the motor  
with a water hose. If it’s accidentally flooded, have it  
inspected at a A.O. Smith authorized service center.  
The ball bearings  
L U B R I C AT I O N  
in A.O. Smith  
motors are double sealed, permanently lubricated. If it  
appears the bearings have failed, simply replace them.  
18  
MOTOR TROUBLESHOOTING  
Before you even touch the  
motor, MAKE SURE THE  
WA R N I N G  
POWER IS OFF. Always turn the power off at the  
electrical service entrance fuse or breaker box, to  
prevent possible electric shock. To prevent electrical  
shock when touching the motor, be sure windings and  
capacitor are securely grounded to the ground terminal  
which should be used in conformity with local codes.  
Don’t work on electrical operations if water or moist  
conditions cannot be avoided. If the motor is not  
operating properly, refer to the following guide.  
MOTOR FAILS TO START (makes no sound)  
1.Check the obvious first — are the power switch  
and timer on?  
2.Be sure fuses are of proper size and type, then  
check for a blown fuse or tripped circuit breaker.  
3.Be sure the motor is connected correctly (as shown  
on motor nameplate), but first — TURN OFF THE  
POWER. Check the terminal screw to see if it was  
tightened onto wire insulation instead of the wire  
itself. Verify that the ground wire is firmly  
connected to the green ground screw.  
4.Check the voltage at terminal board after first  
TURNING THE POWER BACK ON. Be sure you turn  
the POWER BACK OFF after completing this step.  
NOTE: Voltage at motor terminals should be ±10%  
of voltage on nameplate. If the voltage is high  
(more than ±10% above nameplate number),  
consult the local power company. If the voltage is  
low (±10% below rated voltage), check the size of  
the power line from fuse box to motor. If the  
19  
voltage is within the proper range, check for  
continuity through the protector.  
5.Check for overloading from other appliances on  
the same circuit as the motor.  
6.Inspect the motor windings for continuity.  
7.If voltage is proper at terminals and the motor is  
cold, remove the motor and take it to a A.O. Smith  
Authorized Service Center.  
MOTOR FAILS TO START (hums, tries to start, blows  
fuse or trips breaker)  
1.Check the motor connections after TURNING OFF  
THE POWER.  
2.Check the voltage (see #5 above) as the motor tries  
to start. If voltage is too low, look for undersized  
wiring, an overloaded circuit or a burned start  
winding.  
3.If the voltage is proper at terminals and motor is  
hot, TURN OFF THE POWER and allow the motor to  
cool to ambient temperature then reapply power.  
If the motor starts then shuts down, you have an  
overload. Check the amp draw at the motor  
terminal and compare it to amps shown on the  
motor nameplate. If the amp draw is greater then  
the nameplate current, check for impeller rub in the  
pump or a tight seal. If this fails to correct the  
problem, remove the motor from pump and take to  
a A.O. Smith Authorized Service Center.  
4.Check the capacitor but first — TURN OFF THE  
POWER. After removing the capacitor from the  
motor, discharge it by laying an insulated  
screwdriver across its terminals. Check the  
20  
MOTOR TROUBLESHOOTING  
capacitor using an ohmmeter (see  
Troubleshooting A Capacitor” page 23).  
5.Rotate the motor shaft. If you hear a grinding  
sound, disassemble the motor and check: the  
conditions of bearings, a rotor rubbing the stator,  
corrosion, a cracked frame, clogged fan or  
obstruction(s). Repair or replace any faulty part(s).  
6.If the motor has a switch, disassemble the motor  
and check the contacts for dirt. Use brown Kraft  
paper to gently clean. If the motor still doesn’t  
work, replace the switch.  
7.If the switch contacts are open, check the governor  
for free movement on the shaft. (Incidentally, with  
a Centurion motor you won’t have this problem,  
because it doesn’t have a switch to malfunction.)  
MOTOR STARTS BUT SHUTS DOWN (Thermal  
Overload Protection)  
1.Check the voltage at motor terminal (see #5 under  
“Motor Fails To Start”). If the voltage is too high,  
call power company.  
2.Check amperage. If high, find out it the pump  
impeller was recently replaced (it could be sized  
incorrectly). Remember, motor Hp x SF = the  
maximum Hp capability of motor. This number  
must be equal to or greater than the pump rating.  
NOISY MOTOR  
Air noise is normal, but an excessively high sound  
level or rough operation can mean trouble. If necessary,  
separate the motor and pump to find out where the fault  
lies. If it’s in the motor, check the following items:  
21  
1.Mounting, motor coupling and brackets. Tighten  
loose nuts, bolts or set screws.  
2.If a noticeable drag is present, check the bearings  
and bearing load spring.  
3.Make sure motor fan moves freely and rotor isn’t  
rubbing stator. Look for loose or binding parts  
inside the motor or pump.  
4.Check for malfunctioning motor start switch and  
governor.  
If the problem appears to be with the pump, look for a  
loose motor coupling, loose or damaged pump impeller,  
clogged pump filter or strainer, or cavitation (loss of  
prime or air leaks on the pump’s suction side).  
MOTOR HOT, SMOKING OR CYCLING  
1.Check the motor’s ventilation by looking for  
clogged air vents or openings. Clean out all leaves,  
dirt and other pool and spa gunk.  
2.Compare connections and wiring to diagrams.  
Test the motor voltage to verify that it’s within  
±10% of nameplate listing.  
3.If the voltage checks out but amps are higher than  
the maximum on the nameplate, inspect motor and  
pump for mechanical obstructions, but not before  
TURNING OFF THE POWER.  
4.Ensure that the motor’s horsepower (Hp), times the  
service factor (SF), is equal to or greater than the  
pump rating (Hp x SF £ to Pump Rating). A  
full-load current greater than the nameplate listing  
can mean excessive pump load.  
5.Look at motor windings for damage or signs of  
shorting. Measure winding resistance.  
22  
MOTOR TROUBLESHOOTING  
6.Check the start switch for broken contact welds or  
a broken spring.  
7.Check the capacitor with an ohmmeter. A bulged  
capacitor indicates failure on most motors. But  
with a Centurion, the only way to verify a failed  
capacitor is with the ohmmeter.  
INFORMATION NEEDED FOR MOTOR REPLACEMENT  
To get the right replacement motor, you’ll need impor-  
tant information. Fortunately, they all can be found on  
the motor nameplate. Here’s what you’ll need to know:  
1.Mounting configuration - C-Bracket, Square Flange,  
or Through-bolt Mount (See page 5-7).  
2.Horsepower  
3.Service factor  
4.Voltage  
5.Pump part number, manufacturer brand name  
TROUBLESHOOTING A CAPACITOR  
To check a capacitor with an ohmmeter,  
first TURN OFF THE POWER. If possible,  
remove the capacitor from the motor.  
Use an insulated screwdriver to discharge  
the capacitor by shorting it across its terminals.  
Then set the ohmmeter to its highest setting and attach  
the ohmmeter’s clips to the capacitor’s terminals.  
Check for the following indications:  
1.Needle drops to zero range and slowly rises —  
capacitor is probably OK.  
2.Needle drops to zero and stays there —  
capacitor most likely is shorted.  
3.Needle remains at a high value — capacitor may  
have an open circuit.  
23  
BEST WAY TO USE A VOLT-AMMETER  
For Voltage Check  
1.Attach leads to the volt-ammeter  
and select the proper voltage scale
2.Test voltage at the motor line terminals and verify  
that it’s within limits while the motor is operating.  
3.Voltage should be within ±10% of the design  
voltage specified on the motor nameplate.  
For Amperage Check  
1.Remove the leads from the  
volt-ammeter if attached. Select  
lowest reading amperage scale  
according to motor nameplate rating.  
2.Clamp instrument around one incoming lead at the  
motor terminal board.  
3.Observe the amperage as motor runs. With proper  
voltage, the reading should not exceed the  
MAXIMUM LOAD or SF amps rating of the motor.  
HOW TO REPLACE BEARINGS  
Replacing the bearings in a motor isn’t a difficult task,  
provided you follow set procedures. These instructions  
explain the correct method of motor bearing removal  
and replacement. If a bearing is noisy or doesn’t run  
smoothly, it should be replaced. If a bearing has been  
removed for any reason, it should be replaced with a  
new one. As a rule, if it’s necessary to replace one  
bearing, replace the other as well.  
Use only A.O. Smith bearings with the proper part  
number for the motor that you’re working on. A.O.  
Smith bearings are lubricated and require no further  
attention during their life. Do not substitute or reuse old  
24  
MOTOR TROUBLESHOOTING  
bearings because this could damage the motor and  
cause a return service call.  
1.TURN THE POWER OFF  
2.Remove the cover from the motor and disconnect  
the electrical supply leads from the terminal board.  
Then remove the electrical cable  
or conduit from the end frame.  
3.Remove the motor from the  
pump unit.  
4.Mark the brackets and frame  
of the motor, to assure correct  
alignment of these parts when reassembling them.  
5.Remove the rotor and shaft from the frame of the  
motor, following these steps as necessary:  
a)Take out the thru-bolts that secure the brackets  
to the frame.  
b)Remove the bracket opposite the shaft by  
placing a screwdriver blade in the notches of  
this bracket and tapping the handle of the  
screwdriver.  
c)Remove the locking collar screws and washers if  
their use prevents removal of the rotor assembly  
from the shaft end bracket.  
d)Carefully pull the shaft/rotor assembly out of the  
shell or stator toward the shaft extension end.  
e)Be careful not to lose the washer and bearing  
load spring that is positioned in the bottom of the  
bearing bore of the bracket opposite the shaft  
extension. Be sure to replace this spring during  
reassembly.  
25  
6.Remove the bearing(s) from the motor shaft,  
following these steps as necessary:  
a)Remove shaft collars used to secure bearings.  
Don’t reuse a bearing that is removed from  
the shaft.  
7.Install the new shaft bearing(s). It is important  
to press only on the bearing inner race. The  
bearing will be damaged if the outer race surface  
is pressed.  
a)Fan end. Place the short end of the shaft on a  
wood block. Place the bearing (and other parts  
used) over the long end of the shaft. Tap the  
bearing into place, using the proper size tube and  
a mallet. Attach any other parts (as used) to the  
long shaft end.  
b)Opposite end. Place the long end of the shaft on  
the wood block. Place the bearing over the short  
end of the shaft. Tap the bearing into place, using  
the proper size tube and a mallet.  
8.Reassemble the motor in reverse of the  
disassembly procedure.  
a)Observe all reassembly precautions.  
b)Check wiring diagrams to assure proper wiring if  
the leads have been removed from the terminals.  
c)TURN ON THE POWER. Check the motor for  
proper electrical and mechanical operation when  
it has been reinstalled.  
26  
SERVICE  
f your pool or spa motor should need attention  
while still under warranty, we require that you have  
it serviced at a Authorized A.O. Smith Service Center  
I
to qualify for warranty coverage. When ordering parts,  
refer to the part number and serial number on  
the motor nameplate.  
For your convenience, a separate Century Stock  
Pool and Spa Motor Parts List is available. Ask for  
Bulletin #3996.  
27  
WIRING DIAGRAMS  
TABLE OF CONTENTS  
®
Centurion Switchless (Easy Connect) ..................29, 30  
®
Centurion Switchless (Mfg. prior 11/91).......31, 32, 45  
1081, Wishbone (Old Style)............................3. 3, 34, 35  
1081, Single Arm Switch (Old Style).....................36, 37  
®
E-Plus , Switchless (Old Style),230 volt .....................38  
2-Speed, Wishbone (Old Style).......................39, 40, 41  
Micro-Switch (Formerly Gould-Guard)........................42  
Switchless (Formerly Gould-Guard)......................43, 44  
®
Centurion Solid State...........................................4..6, 47  
®
E-Plus Switchless (Mfg. prior 11/91) ...................48, 49  
®
Lasar 48 Frame (Two Speed)........................5. 0, 51, 52  
Flex 48 (Single Speed).........................................5..3, 54  
Neptune................................................................5..5.., 58  
28  
CENTURION®/SE/II  
For motors manufactured in/after Nov., 1991 (Serial #BJ11)  
Dual Voltage  
230/115 Volt  
Type CX-12 to 112 Hp  
Switchless  
29  
CENTURION®/SE/II  
For motors manufactured in/after Nov., 1991 (Serial #BJ11)  
Single Voltage  
230 Volt  
Type CX-112-5Hp  
Switchless  
30  
CENTURION®  
For motors manufactured prior to Nov. 1991. (Serial #BJ11)  
Type CX–12 to 112 Hp  
Switchless  
Dual Voltage  
115/230 Volt  
31  
CENTURION®  
For motors manufactured prior to Nov. 1991. (Serial #BJ11)  
Single Voltage  
230 Volt  
Type CX–2, 3 & 4 Hp  
Switchless  
32  
1081  
115/230 Volt  
Type CS–12 to 112 Hp  
Wishbone (Old Style)  
33  
1081  
115/230 Volt  
Type CP–2 Hp  
Wishbone (Old Style)  
34  
1081  
230 Volt  
Type CP–3 Hp  
Wishbone (Old Style)  
35  
1081  
115/230 Volt  
Type CS–12 to 112 Hp  
Single Arm Switch (Old Style)  
36  
1081  
115/230 Volt  
Type CP–2 Hp  
Single Arm Switch (Old Style)  
37  
E-PLUS®  
230 Volt  
Type CX–2 and 3 Hp  
Switchless (Old Style)  
38  
2-SPEED  
115 Volt  
Type CSM–12 to 34 Hp  
Wishbone (Old Style)  
39  
2-SPEED  
230 Volt  
Type CSM–1 and 112 Hp  
Wishbone (Old Style)  
40  
2-SPEED  
230 Volt  
Type CPM–2 Hp  
Wishbone (Old Style)  
41  
MICRO-SWITCH MOTOR  
(Formerly identified as  
Gould-Guard)  
Type CS–12 to 1 Hp  
(Old Style)  
115/230 Volt  
42  
SWITCHLESS MOTOR  
(Formerly identified as  
Gould-Guard)  
230 Volt  
Type CX–112 HP  
Switchless (Old Style)  
43  
SWITCHLESS MOTOR  
(Formerly identified as  
Gould-Guard)  
230 Volt  
Type CX–2 and 3 HP  
Switchless (Old Style)  
44  
CENTURION®  
Two-Speed  
Single Voltage  
115 Volt  
Type CXPM–12 /.06 to 34 /.10 Hp  
Solid-State Switch  
46  
CENTURION®  
Two-Speed  
Single Voltage  
230 Volt  
Type CXPM–1/.12 to 2/.25 Hp  
Solid-State Switch  
47  
E-PLUS® SWITCHLESS  
Dual Voltage  
115/230 Volt  
Type CX–34 to 112 Hp  
Switchless  
48  
E-PLUS® SWITCHLESS  
Single Voltage  
230 Volt  
Type CX–2 and 3 Hp  
Switchless  
49  
FLEX 48® FRAME  
Two Speed Single Voltage  
115 Volt  
Type SPM–34 /.10 HP  
50  
FLEX 48® FRAME  
Two-Speed  
Single Voltage  
115 or 230 Volt  
Type CXSM 112 /.18 HP  
Type CXSM 2.0/.25 HP  
through 4.5/.50 Spl HP  
51  
FLEX 48® FRAME  
Two-Speed  
Single Voltage  
115 or 230 Volt  
Type CSM 1.0/.12 Hp 115 Volt  
Type CSM 1.0/.16 Hp 115 Volt  
Type CSM 1.5/.18 Hp 230 Volt  
Type CSM 2.0/.25 Hp 230 Volt  
52  
FLEX 48®  
Single Voltage  
115 Volt  
Type SP–12 to 112 Hp  
53  
FLEX 48®  
Dual Voltage  
230/115 Volt  
Type CS–112 to 4 Spl Hp  
54  
HOW TO IDENTIFY  
THE DATE OF  
MANUFACTURE  
For Century Pool, Spa or Jetted Tub Motors  
To identify the month and year your Century pool, spa  
or jetted tub motor was manufactured you need to know  
the serial code.  
The serial code on the nameplate is made up of three  
parts: serial letter (year), serial number (month), and  
manufacturing sequence number. Example:  
SERIAL BH 11-16  
Serial Letter  
Serial Number  
Mfg. Sequence  
This motor was manufactured in November 1990.  
Serial Letter Designation  
Serial  
Letter Year  
Serial  
Letter Year  
Serial  
Letter Year  
K
L
1970  
1971  
1972  
1973  
1974  
1975  
1976  
1977  
1978  
W
X
1979  
1980  
1981  
1982  
1983  
1984  
1985  
1986  
1987  
BF  
1988  
1989  
1990  
1991  
1992  
1993  
1994  
1995  
1996  
BG  
BH  
BJ  
M
N
P
R
S
T
Y
Z
BA  
BB  
BC  
BD  
BE  
BK  
BL  
BM  
BN  
BP  
U
Serial No. Designation  
Serial  
Letter Year  
Serial  
Letter Year  
1
2
3
4
5
6
JAN  
7
JULY  
AUG  
SEPT  
OCT  
NOV  
DEC  
FEB  
8
MAR  
APR  
MAY  
JUNE  
9
10  
11  
12  
55  
®
NEPTUNE 2 Compartment Motors  
Single Voltage  
Type CP  
230 Volt  
112 2&3 Hp  
56  
®
NEPTUNE 2 Compartment Motors  
Dual Voltage  
230/115 Volt  
Type CP  
12-112 Hp  
57  
®
NEPTUNE 2 Compartment Motors  
Dual Voltage  
230/115 Volt  
Type CS  
13-112 Hp  
58  
A.O. Smith  
531 North Fourth Street  
Tipp City, OH 45371  
937-667-6800  
Fax (937) 667-5873  
Bulletin 2944  
©
A.O. Smith 2000 Litho in USA
 
#2944 11/00  

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