CHEMPUMP NC Series User manual

Instruction Manual
for: Installation,Operation, & Maintenance
CHEMPUMP
Sealless Leakproof Canned Motor Pump
NC SERIES
2/04

Table of Contents
Paragraph Page
SECTION 1. GENERAL INFORMATION
1-1.GeneralDesignandOperation......................................................................................................... 1-1
1-2. Stator Assembly ............................................................................................................................. 1-3
1-3.RotorAssembly .............................................................................................................................. 1-3
1-4.Bearings.......................................................................................................................................... 1-3
1-5.ThrustWashers............................................................................................................................... 1-3
1-6.CoolingFlow ................................................................................................................................... 1-3
1-7.AutomaticThrustBalance ............................................................................................................... 1-3
SECTION 2. INSTALLATION
2-1.ReceiptInspection............................................................................................................................ 2-1
2-1.1.StorageNote .......................................................................................................................... 2-1
2-2.Structural ......................................................................................................................................... 2-1
2-2.1.PumpLocation ....................................................................................................................... 2-1
2-2.2.MountingandAlignment ......................................................................................................... 2-1
2-2.3.PipingData............................................................................................................................. 2-2
2-3. Electrical.......................................................................................................................................... 2-3
2-3.1.General................................................................................................................................... 2-3
2-3.2.ThermalCut-Out ..................................................................................................................... 2-3
2-3.3.StartingEquipment ................................................................................................................. 2-3
2-3.4. Oil Filled Stator....................................................................................................................... 2-5
2-3.5.DirectionofRotationIndicator ................................................................................................. 2-5
2-3.6. IntelliSense Diagnostics System ............................................................................................ 2-5
2-4.SpecialConditionsandFeatures...................................................................................................... 2-6
2-4.1.Backflushing ........................................................................................................................... 2-6
2-4.2.ReverseCirculation ................................................................................................................. 2-6
2-4.3.ElectricalIsolation .................................................................................................................. 2-7
2-4.4. Water and Steam Jackets ...................................................................................................... 2-7
2-4.5.HeatExchanger ...................................................................................................................... 2-7
2-4.6.InternalCirculation .................................................................................................................. 2-7
SECTION 3. OPERATION
3-1. ProcedureBeforeInitialStart-up...................................................................................................... 3-1
3-2. Priming and Venting........................................................................................................................ 3-1
3-3. Rotation Check ............................................................................................................................... 3-1
3-4. StartingProcedure .......................................................................................................................... 3-1
3-5. OperationDetails ............................................................................................................................ 3-2
3-6. ShutdownProcedure ....................................................................................................................... 3-2
i

SECTION 4. MAINTENANCE
4-1. PeriodicInspection.......................................................................................................................... 4-1
4-1.1. RecommendedToolsForDisassemblyandReassembly....................................................... 4-1
4-1.2. RecommendedToolsForInspection ...................................................................................... 4-1
4-2. Disassembly ................................................................................................................................... 4-1
4-3. Inspection ....................................................................................................................................... 4-2
4-3.1. BearingInspection ................................................................................................................. 4-2
4-3.2. Automatic Thrust Balance and End Play Inspection................................................................ 4-3
4-3.3. Rotor Assembly Inspection .................................................................................................... 4-3
4-3.4. Stator Assembly Inspection................................................................................................... 4-3
4-3.5.GeneralInspection.................................................................................................................. 4-3
4-4. Reassembly.................................................................................................................................... 4-3
4-5. IntelliSenseCalibrationProcedure ................................................................................................... 4-4
4-6. Lubrication ...................................................................................................................................... 4-4
4-7. Cooling............................................................................................................................................ 4-4
4-8. Service Policy ................................................................................................................................. 4-5
4-9. Spare Parts..................................................................................................................................... 4-5
APPENDIX
Sample: Trouble Analysis Sheet ............................................................................................................ A-1
FluidDecontamination(Page1of2)........................................................................................................ A-2
FluidDecontamination(Page2of2)........................................................................................................ A-3
PerformanceCurves
ModelNC-AA-6................................................................................................................................. A-4
ModelNC-AB-6................................................................................................................................. A-5
ModelNC-AA-8................................................................................................................................. A-6
ModelNC-A50-8 ............................................................................................................................... A-7
ModelNC-A60-8 ............................................................................................................................... A-8
ModelNC-A05-10 ............................................................................................................................. A-9
ModelNC-A50-10 ............................................................................................................................. A-10
ModelNC-A60-10 ............................................................................................................................. A-11
OutlineDrawings
ModelsNC-AA&NC-AB .................................................................................................................. A-12
ModelsNC-A05,NC-A50&NC-A60.................................................................................................. A-13
CrossSectionDrawing(allmodels)......................................................................................................... A-14
Figures
1-1 NCSeriesStandardCirculation.................................................................................................. 1-1
1-2 DischargeFilterArrangement .................................................................................................... 1-1
1-3 NCSeriesChempumps ............................................................................................................. 1-2
1-4 NCSeriessleevetypebearing ................................................................................................... 1-3
1-5 Automatic Thrust Balance.......................................................................................................... 1-3
2-1 Easy Maintenance Base............................................................................................................ 2-2
2-2 Wiring Diagram 460 Volt, 3 Phase ............................................................................................. 2-4
2-3 WiringDiagramvoltagesotherthan460 ..................................................................................... 2-4
2-4 Typical Backflush System ......................................................................................................... 2-6
2-5 ReverseCirculationSystem ....................................................................................................... 2-6
ii

Tables
2-1 NC Series Electrical Data .......................................................................................................... 2-5
2-2 Recirculation FlowRate ............................................................................................................. 2-6
2-3 Electrical Wiring Data, 230 Volt ................................................................................................. 2-8
2-4 Electrical Wiring Data, 460 Volt ................................................................................................. 2-8
2-5 Electrical Wiring Data, 575 Volt ................................................................................................. 2-8
4-1 NCSeriesBearingandJournaldimensions................................................................................ 4-3
4-2 Coil Resistance Values.............................................................................................................. 4-6
4-3 TroubleShooting........................................................................................................................ 4-7
iii

SECTION 1. GENERAL INFORMATION
1-1. General Design and Operation
The NC Series is a combined centrifugal pump and
squirrel cage induction electric motor built together
into a single hermetically sealed unit. The pump
impellerisoftheclosedtype,andismountedonone
end of the rotor shaft which extends from the motor
section into the pump casing. The rotor is
submerged in the fluid being pumped and is,
therefore, “canned” to isolate the motor parts from
contact with the fluid. The stator winding is also
“canned” to isolate it from the fluid being pumped.
Bearings are submerged in system fluid and are,
therefore, continually lubricated.
The Chempump has only one moving part, a
combinedrotor-impellerassemblywhichisdrivenby
themagneticfieldofaninductionmotor.Aportionof
thepumpedfluidisallowedtorecirculatethroughthe
rotor cavity to cool the motor and lubricate the
bearings. The stator windings are protected from
contact with the recirculating fluid by a corrosion
resistant,non-magnetic,alloylinerwhichcompletely
seals or “cans” the stator winding. The recirculating
fluid passes through a self-cleaning cylindrical filter
(fitted in the discharge nozzle of the pump casing),
through the circulation tube, to the motor adapter,
entering the motor section at the front bearing. A
portion of the pumpage flows across the front
bearing and returns to the rear of the impeller. The
remainder passes over the rotor, across the rear
bearing, and returns to suction through a hollow
shaft. See Figure 1-1.
Figure 1-1: NC Series Chempump
Standard Circulation
The discharge filter, Figure 1-2, located in the
dischargenozzleofthepumpcasing helpstoextend
motorandbearinglifebykeepingthecirculatingfluid
freeofdamaging particles.Thisfilterisopentopand
bottom and is constantly washed by the discharge
flow.Certaintypesofsolidsaregummyandwilladhere
to the fine wire mesh, thus restricting flow to the
bearings. An indication of restricted flow will be
increased temperature in the motor section and
subsequenthighertemperatureofthemotorhousing.
Ifthisoccurs,aninspectionofthefiltershouldbemade
todeterminecauseofrestricted flow.
Figure1-2: DischargeFilterArrangement
TheChempumpseallesspumpisaprecision-builtunit
that, with proper care, will give years of trouble-free,
leakproof service. This manual, containing basic
instructionsforinstallation,operationandmaintenance
ofChempumps,isdesignedtoassistyouinobtaining
thisservice.
It is important that the persons responsible for the
installation,operation,andmaintenanceofthepump,
readandunderstandthemanualthoroughly.Trouble-
freeChempumpperformancebeginswithproperpump
selection and application. If the selected pump does
nothavetherequiredperformancecharacteristics,or
if the materials of construction are not properly
specified for the fluid being handled, unsatisfactory
operationmayresult.Noamountofmaintenancecan
compensateforthis.
If you are in doubt on Chempump selection or
application,writeorcallyourChempumpengineering
representativeorthefactoryforassistanceandadvice.
Additionalcopiesofthismanualareavailablefromthe
Chempumpfieldrepresentativeorfromthefactory.
Theentireunitismountedona fabricatedsteelbase
plate. Operation is unaffected by the mounting or
operatingposition,eliminatingtheneedforanycostly
alignmentprocedures.SeeFigure1-3,Page1-2.
Page 1-1

Figure1-3: NCSeriesChempumps
Page 1-2

1-2.StatorAssembly
Thestatorassemblyconsistsof asetofthree-phase
windingsconnectedinaonecircuitwyearrangement.
Stator laminations are of low-silicon grade steel.
Laminations and windings are mounted inside the
cylindricalstatorband.Endbells,weldedtothestator
band,closeofftheendsofthestatorassembly.Back
upsleevesareprovidedtostrengthenthoseareasof
the stator liner not supported by the stator
laminations.Thestatorliner is,ineffect,acylindrical
“can”placedinthestatorboreandweldedtotherear
endbellandfrontendbellshroudtohermeticallyseal
off the windings from contact with the liquid being
pumped.Terminalleadsfromthewindingsarebrought
outthroughapressuretightleadconnectormounted
on the stator band and terminated in a standard
connectionbox.
1-3.RotorAssembly
The rotor assembly is a squirrel cage induction rotor
constructedandmachinedforuseintheChempump.
It consists of a machined corrosion resistant hollow
shaft,laminatedcorewithcopperbarsandendrings,
corrosion resistant end covers, and a corrosion
resistant can. The shaft is provided with an impeller
keyarrangementatoneendtoreceivetheimpellerand
isthreadedatthesameendtoreceivetheimpellernut
whichretainstheimpeller.
Therotorendcoversareweldedtotheshaftandalso
to the rotor can which surrounds the outside of the
rotor,thushermeticallysealingofftherotorcorefrom
contact with the liquid being pumped.
Theshaftisfittedwithreplaceableshaftsleevesand
thrust surfaces. These parts are keyed to prevent
turning. Axial movement is restricted by the impeller
hub in the front and by a retaining nut in the rear.
1-4.Bearings
The bearings for the NC Series are metal sleeved
carbon/graphite as standard (other materials are
furnished depending on the application) and are
machinedwithaspecialhelixgroovethroughthebore
toassureadequatefluidcirculationatthejournalarea.
Eachbearingismanufacturedtoclosetolerancesfor
ahighdegreeofconcentricityandisheldinabearing
housing by a retaining screw. Bearings are easily
replacedbyremovingtheretainingscrewandsliding
thebearingfromitshousing. See Figure 1-4.
Figure1-4: NCSeries SleevedTypeBearing
1-5.ThrustWashers
AllNCSeriesChempump modelsareequippedwith
thrust surfaces providing a replaceable bearing
surfaceagainstwhichaxialloadscanbecarriedduring
upset conditions. The shaft is fitted with replaceable
shaft sleeves and thrust surfaces. These parts are
keyedtopreventturning.Axialmovementisrestricted
bytheimpellerhub inthefrontandby aretainingnut
in the rear. These surfaces prevent metal to metal
contactattheimpellerandpumpcasingintheevent
of abnormal pump operation such as running dry or
cavitation.
1-6. Cooling Flow
Cooling for stator, rotor, and bearings, as well as
bearing lubrication, is provided by circulation of the
pumpedfluid.Aportionofthefluidcirculatesthrough
thecirculationtubetothemotoradapter,enteringthe
motorsectionatthefrontbearing.Aportionofthefluid
flowsacrossthe frontbearingand returnstothe rear
oftheimpeller.Theremainderpassesovertherotor,
acrosstherearbearing,andreturnstosuctionthrough
thehollowshaft.SeeFigure1-1,Page1-1.
1-7. Automatic Thrust Balance
Based on hydraulic principles, Chempump’s
automatic thrust balance is accomplished by the
pressure of the pumped fluid itself, operating in a
balance chamber on the front and rear of the
impeller.
When a change in load tends to change the position
of the impeller away from the balance condition,
there is an equalizing change of hydraulic pressure
in the balance chambers which immediately returns
theimpeller-rotorassemblytothebalancedposition.
See Figure 1-5.
Figure 1-5: Automatic Thrust Balance
Page 1-3

SECTION 2. INSTALLATION
2-1.ReceiptInspection
1. Visually inspect the shipping container for
evidence of damage during shipment.
2. Check unit to see that suction and discharge
and any other connections are sealed.
3. Inspect the suction and discharge gasket
seating surface to be certain that they are clean
of foreign matter and free from nicks, gouges
and scratches.
4. Visuallyinspectthe unitforevidenceofshipping
damage:
a. Circulation line bent or compressed
b. Flange faces
c. Junction boxes and nipples on stator
assembly bent or compressed
d. Vent and drain plugs properly installed
5. Megger resistance to ground of the motor
windings.RefertoTable4-2,Page4-6.DONOT
SURGE TEST OR HI POT MOTOR WIND-
INGS.
6. Check all nameplate data against shipping
papers.
7. Caution should be observed during handling so
as not to bend the circulation line.
2-1.1. Storage Note
In situations where a Chempump is to be stored for
a period of time prior to installation and where the
climateexperiences wide temperature changes and
high humidity, the terminal box, suction and
discharge flange, and any other openings must be
sealed to prevent moisture from entering the
internals of the pump.
2-2. Structural
The pump design and construction eliminates the
necessityofaligningthepumpandmotor.Thepump
shouldbesupportedfromthemountingsprovided.It
should be mounted in such a way as to have its
weight properly supported. Suction and discharge
piping must be properly supported and aligned so
that no strain is placed on the pump casing.
General
1. Remove burrs and sharp edges from flanges
when making up joints.
2. When connecting flanged joints, be sure inside
diameters match within 1/16" diametrically so
as not to impose a strain on the pump casing.
3. Use pipe hangers or supports at intervals as
necessary.
2-2.1. Pump Location
Locate the pump as close as possible to the fluid
supply with a positive suction head. Installations
with suction lift are possible but not recommended.
Since standard pumps are not self-priming, provide
for initial priming and for maintaining a primed
condition. Location of the pump and arrangement of
thesystemshouldbesuchthatsufficientNPSH(Net
Positive Suction Head) is provided over vapor
pressure of the fluid at the pump inlet. NPSH
requirements at the design point are stated on the
pumporderdatasheet.Foradditionaldesignpoints,
refer to the corresponding performance curves
located in the Appendix of this manual.
NOTE:
Experience has proved that most
pump troubles result from poor
suction condition including insuffi-
cient NPSH. The suction line must
have as few pressure drops as
possible and available NPSH
MUST be greater than required
NPSH.
Depending on job conditions, available NPSH can
sometimes be increased to suit that required by the
pump for satisfactory operation. NPSH can be
“tailored” by changes in the piping, in liquid supply
level, by pressurizing the suction vessel and by
several other methods. Refer to Table 4-3, Page 4-
7, Trouble Shooting.
Page 2-1

2-2.2. Mounting and Alignment
The Chempump combines a pump and motor in a
single hermetically sealed unit. No tedious coupling
alignment is required because the pump has no
external coupling between pump and motor. All
models can be mounted in any position.
Formountingwithsuction anddischargeontheside
orinanyother position,modificationsmustbe made
to the standard internal venting arrangement.
Basesareoffered onallmodels.Youmerelyhaveto
set the pumps on a foundation strong enough to
supporttheirweight.Thereisnoneedtoboltdownor
grout in a Chempump. All NC Series models are
provided with a specially made base designed to
mount on a standard ANSI baseplate to facilitate
inspection and repair. See Figure 2-1.
Besurethatsuctionanddischargepipingisproperly
aligned so that no strain is placed on the pump
casing by out-of-line piping.
2-2.3. Piping Data
Observe the standards of the Hydraulic Institute
when sizing and making up suction and discharge
piping. Follow these procedures:
1. Remove burrs and sharp edges when making
up joints.
2. When using flanged joints, be sure inside
diameters match properly. When gasketing
flanged joints, DO NOT cut flow hole smaller
than flange opening.
3. Use pipe hangers or supports at necessary
intervals.
4. Provide for pipe expansion when required by
fluid temperature.
5. Whenweldingjoints,avoidpossibilityofwelding
shot entering the suction or discharge line, and
thereby entering the pump. Do not weld pipe
while connected to pump.
6. When starting up a new system, place a
temporary 3/16" mesh screen at or near suction
port of pump to catch welding shot, scale or
other foreign matter. (Refer to Section 3).
7. Do not spring piping when making up any
connections.
8. Make suction piping as straight as possible,
avoidingunnecessaryelbows.Wherenecessary,
use45degreeorlong-sweep90degreefittings.
9. Make suction piping short, direct, and never
smaller in diameter than suction opening of
pump. Suction piping should be equal to or
larger than pump suction port, depending on
pipe length.
10. Insure that all joints in suction piping are air-
tight.
11. When installing valves and other fittings,
position them to avoid formation of air pockets.
12. Permanently mounted suction filters are not
recommended.
It is extremely important to size and layout the
suction system to minimize pressure losses and to
be sure that the pump will not be “starved” for fluid
during operation. NPSH problems are a result of
improper suction systems.
If suction pipe length is short, pipe diameter can be
the same size as the pump suction port diameter. If
suction piping is long, the size should be one or two
sizes larger than pump suction port, depending on
piping length. Use the largest pipe size practical on
suction piping and keep piping short and free from
elbows, tees or other sources of pressure drop. If
elbows, tees or valves must be used, locate them
from10to15pipe diametersupstreamfromsuction.
Figure 2-1. Easy Maintenance Base
Page 2-2

When reducing to pump suction port diameter, use
eccentricreducerswith eccentricsidedownto avoid
air pockets.
Whenoperatingunderconditionswherepumpprime
can be lost during off cycles, a foot valve should be
provided in the suction line to avoid the necessity of
priming each time the pump is started. This valve
shouldbeoftheflappertyperatherthanthemultiple
spring type and of ample size to avoid undue friction
loss in the suction line.
When foot valves are used, or when there are other
possibilities of fluid hammer, it is important to close
the discharge valve before shutting down the pump.
When necessary to connect two or more pumps to
the same suction line, provide gate valves so that
any pump can be isolated from the line. Install gate
valves with stems horizontal to avoid air pockets.
Globe valves should be avoided, particularly where
NPSH is critical.
Ifdischargepipelengthisnormal,pipediametercan
be the same size as the pump discharge port
diameter. If discharge piping is of considerable
length, use larger diameter pipe (one or two sizes
larger).
Ifthepumpistodischargeintoaclosedsystemoran
elevated tank, place a gate valve or check valve in
the discharge line close to the pump. The pump can
then be opened for inspection without fluid loss or
damage to the immediate area.
RECOMMENDED
Install properly sized pressure
gauges in suction and discharge
lines near the pump ports so that
operation of the pump and system
can be easily observed. Should
cavitation,vaporbinding,orunstable
operation occur, widely fluctuating
discharge pressures will be
observed.
Such gauges provide a positive means of
determining actual system conditions and can be
used to great advantage in evaluating system
problems.
2-3. Electrical
2-3.1. General
Except where indicated, all Chempumps are started
with full line voltage. Phase sequence is shown on
the name plate. Refer to Paragraph 3-3, Page 3-1,
for checking direction of rotation. Also see Wiring
DiagramFigures2-2,or2-3,Page2-4dependingon
electrical source characteristics.
2-3.2. Thermal Cut-Out
Unless otherwise specified, all Chempumps are
fitted with thermal cut-outs. The cut-out is a heat-
sensitive bimetallic switch mounted in intimate
contact with the stator windings. It is to be wired in
series with the holding coil in the starter box by
removing a jumper as shown in Figures 2-2 or 2-3,
Page 2-4. Maximum holding coil currents is 3.1
AMPS for 115 volts.
WARNING
Do not connect TCO in series with
main power lead. Excessive heat
build up in the winding area opens
the normally closed thermal switch
which, in turn, opens the holding
coil circuit, shutting off power to the
pump. Be sure to connect the
thermal cut-out as required.
Thermalcut-outsinClassRinsulatedmotorsareset
to open at 425oF. Depending on the application,
specially set TCO’s are sometimes provided. The
pump order data sheet indicates the TCO setting. If
the motor cuts out because of TCO action, there will
be a time delay before the motor can be restarted.
The motor must be restarted manually. DO NOT
RESTARTUNTILYOUDETERMINETHESOURCE
OF THE OVER-HEATING.
WARNING
The thermal cut-out switch does
not provide protection against fast
heat build-up resulting from locked
rotor conditions, single phasing or
heavy overloads. This protection
must be provided for by the current
overload relay heaters in the
magnetic starter. The rating of the
heaters should be high enough to
avoid nuisance cut outs under
running loads, but must not be
oversized.RefertoTable2-1,Page
2-5, for starting and running
electrical characteristics. It is
recommended that “quick trip”
(Class 10 heaters ) be used
becauseofthemorerapidresponse
time.
2-3.3. Starting Equipment
Motor starters (normally not supplied with
Chempump) should be sized to handle the load
required. Start KVA, Full Load Hp and Full Load
Amps Data are listed in Table 2-1, Page 2-5.
Page 2-3

Heaters in the starters should be sized for the
amperageshownontheChempumpnameplate.DO
NOT size heaters in excess of 10% of full load amp
rating. In order to provide complete protection for
Chempump motors under all conditions, it is
recommended that “quick trip” (Class 10) type
heaters be used in the starters where available.
Standard heaters provide adequate protection for
Chempumpmotorsunderstartingor normalrunning
conditions, but require a greater length of time than
“quick trip” type heaters to cut out if the motor is
subject to locked rotor or overload conditions. Also
see Tables 2-3, 2-4, or 2-5, Page 2-8, for electrical
wiring data for the most common Chempump motor
sizestoassistintheelectricalinstallationoftheunit.
Identification Code Motor Stator Temperature Limit
T2D 419°F/215°C
T3C 320°F/160°C
CASEI -460 VOLT,3-PHASE CHEMPUMP
(SeeFigure2-2).
Typical3-phaseacross-the-linemagneticstarter
with start-stop push button station shown.
Figure 2-2: Wiring Diagram 460 Volt, 3 Phase
Figure 2-3: Wiring Diagram voltages other than
460 Volt, 3 Phase
Thermoswitch (thermal cut-out inside Chempump
motor) is wired in series with holding coil circuit by
removing jumper between over load cut-outs as
shown.
Be sure to size heaters properly. Rating should be
as close as possible to current draw noted on pump
nameplate.
CASE II - All other voltages (not to exceed 600
volts), 3-PHASE CHEMPUMP (See Figure 2-3).
Use transformer with primary and 115 volt
secondary. Use properly rated holding coil (115
volt). Wire Thermoswitch as for 460 volt systems
described in Case 1.
Page 2-4

TABLE 2-1. NC Series Electrical Data
FULL AND FULL AND FULL AND MAX
FULL FULL NO LOAD NO LOAD NO LOAD PROCESS
MOTOR START LOAD LOAD CURRENTS CURRENTS CURRENTS FLUID
SIZE KVA KW BHP AT 230 AT 460 AT 575 TEMP AT
VOLTS VOLTS VOLTS FULL
F.L./N.L. F.L.N.L. F.L./N.L. LOAD
N1 25.5 7.0 6.8 20.8 / 7.2 10.4 / 3.6 8.3 / 2.9 300
N2 43.8 13.4 13.5 37.2 / 9.8 19.6 / 4.9 15.7 / 3.9 300
N3 89.2 21.7 23.0 63.0 / 16.8 31.5 / 8.4 25.2 / 6.7 280
N4 119.5 30.9 34.0 88.0 / 24.0 44.0 / 12 35.2 / 9.6 260
N5 227.1 48.0 50.8 133.8 / 35 66.9 / 17.5 53.5 / 14.0 290
energizedandthelightdoesnotgoon,reverseanytwo
motorleadsandstarttheunitagain.Thiswillreverse
thedirectionoftherotationandthelightwillglow.The
bulb in the D.R.I. has a rated life of 2-1/2 years.
2-3.6. IntelliSense Diagnostics System
Chempump’s IntelliSense diagnostic system
(patentappliedfor)isdesignedtodetectanychange
in the rotor position in either the axial or radial
direction. A change in rotor position will cause a
change in the sensor output. By comparing this
output to the established baseline (or as new data)
the condition of the pump internal bearings is
indicated and interpreted as bearing wear.
The display of the output is configured to show the
percentage of bearing wear which has occurred.
Since the maximum allowable displacement has
been determined, the inherent accuracy of the
IntelliSense diagnostic system gives a greater
bearing wear safety margin than other bearing wear
indicators, especially those that operate on single
point failure.
The IntelliSense diagnostic monitor has been
designed to accommodate a variety of output
options and can be configured to match existing or
future plant instrumentation without significant
modification.
Following bearing replacement the only calibration
required is for radial position. This is accomplished
by using the procedure described in Section 4-5.,
Page 4-4.
Pleaseconsultthe Chempump factory for questions
or service on the IntelliSense monitor. Do not adjust
or repair the unit in the field. A factory program has
been established for replacement of damaged
monitors.
2-3.4. Oil Filled Stator
The NC Series Chempumps are designed to give
long, trouble-free service. In order to facilitate the
dissipation of heat from the motor section, the stator
cavity on standard NC Series Chempumps can be
filled at the factory with a heat conductive dielectric
oil. This oil filling allows the heat generated by the
motor to be conducted to the outside of the unit,
thereby maintaining a lower temperature in the
motor section and thereby extending the life of the
motor. Solid filled or non oil-filled options are
available for any applications where an oil filled
stator is not desirable.
2-3.5. Direction of Rotation Indicator
The Chempump is a seal-less, leakproof, canned
motor pump that combines the pump and motor into
a single unit. Because of this design, no rotating
parts are exposed to view. This makes it difficult to
determine the direction of rotation of the pump.
The exclusive Chempump Direction of Rotation
Indicator, (D.R.I.), indicates if the pump is rotating in
the correct direction. The Chempump D.R.I.
eliminates the use of phase sequence indicators,
discharge gauges and other bothersome methods
used by plant engineers to insure proper pump
rotation.
The Chempump D.R.I. is the easy, positive way to
check on pump rotation. The entire unit is a
compact, unobtrusive part of the normal electrical
junction box. No additional installation work is
required,justwire thepumpandtheD.R.I.isreadyto
work. When the direction of rotation is correct, an
amber light, located on the unit is lit. If the pump is
Page 2-5

2-4. Special Conditions and Features
2-4.1. Backflushing
For normal clear fluid applications, NC Series
Chempumps are cooled and lubricated by the fluid
being pumped. For slurry and other “dirty”
applications, a system of backflushing is
recommended. Backflushing is noted on the order
when recommended. See Figure 2-4 for a typical
back flush installation.
Figure 2-4: Typical Backflush System
Chempumpstobeusedwithbackflusharenormally
supplied without circulating tubes. Clear fluid is
brought to the fitting at the front of the motor section
by customer’s piping as shown in Figure 2-4. The
amount of clear base fluid introduced in this manner
should approximate the standard flow rates listed in
Table 2-2.
TABLE 2-2.
RECIRCULATION FLOW RATE
RECIRCULATION RECIRCULATION
MODEL FLOWRATE FLOWRATE
(GPM) (M3/HR)
NC-AA-6 2.5 - 4.5 0.57 - 1.0
NC-AA-8 3 - 6 0.68 - 1.36
NC-AB-6 3.5 - 4.5 0.79 - 1.0
NC-A50-8 5 - 7 1.14 - 1.59
NC-A60-8 5 - 7 1.14 - 1.59
NC-A05-10 7 - 9 1.59 - 2.04
NC-50-10 7 - 9 1.59 - 2.04
NC-A60-10 8 -10 1.82 - 2.27
Backflushpressureshouldbesuctionpressure plus
20-30% of the pressure developed by the pump.
Excessivebackflushpressurewilldestroythe thrust
balancedoperationbuiltintoNCSeriesChempumps
by causing excessive forward thrust.
Procedure:
1. Removethecirculationtubeandplugofftheport
in the discharge neck of the pump casing. (This
is done at the factory if specified in the order).
2. Supply clear liquid to the port in the adapter
normally used for the circulating tube size.
3. If thebackflushingliquidishot,auxiliarycooling
methods, such as water jacketing the stator
must be employed. The temperature of the
backflush fluid should not be close to its boiling
point and should not exceed 300oF.
2-4.2. Reverse Circulation
For normal clear fluid applications, NC Series
Chempumps are cooled and lubricated by the fluid
being pumped. However, when the fluid being
pumped is at or near its boiling point, the additional
heat picked up from the motor combined with the
recirculation fluid returning to the low pressure at
impeller suction may cause vaporization inside the
pump.Inthesecasesthereversecirculationmethod
of lubricating the bearings and cooling the motor
should be used. Flow rates should duplicate those
shown in Table 2-2.
Inreversecirculationthecoolingandlubricatingfluid
is forced from behind the impeller into the motor
section.Itpasses throughthefrontbearing, overthe
rotor and across the rear bearing. The fluid then
exits the rear of the pump and is piped back to the
suction vessel (not the suction line).
Figure2-5: ReverseCirculationSystem
Page 2-6

By this method, the fluid in the motor section is
maintained at a pressure close to discharge
pressure.
Flow through stator-rotor cavity must be controlled
to allow for good balance of pressure and
temperaturewithoutexcessiveflow.SeeFigure2-5,
Page 2-6, for a typical reverse circulation
installation.
Procedure:
1. Connect tubing (minimum 1/2") to the port
provided in the outboard bearing housing.
2. Runthetubingfromtheconnection port fittingin
the rear back to the suction receiver, preferably
above the liquid level.
3. Uselargesizesuctionlineandgatevalveforlow
pressure drop and thus improve Available
NPSH.
2-4.3 Electrical Isolation
To eliminate electrolytic corrosion when handling
solutions during an electrolysis or plating operation,
Chempumps should be electrically isolated.
Insulated couplings or non-conductive plastic piping
must be used in the primary suction and discharge
lines. The Chempump must be isolated electrically
from the tank, and separately grounded.
2-4.4. Water and Steam Jackets
When handling fluids at controlled temperatures,
additional motor cooling or heating must be
provided. For temperature control, jackets are
provided for water, steam or other heat transfer
media. Also, the pump can be submerged into the
pumped fluid, thus providing an additional means of
temperature control.
All NC Series Chempumps can be provided with
removable type water jackets. This type jacket is
easily removable from the stator band to allow for
inspection and possible replacement. Removable
type water jacket kits are available from the factory
for Chempumps already installed in the field when
additionalstatorcoolingisrequired.Thesejacketsare
suitableonlyforheatingmediumscompatiblewiththe
gasket and jacket material, with maximum inlet
pressureof50psiandwithmaximumtemperatureof
150oF. They should not be used as steam jackets.
Jacketsweldedtothestatorbandareavailableforuse
as steam jackets and for liquid mediums which
exceedthetemperaturesandpressuresnotedabove.
Normally welded type jackets are suitable for steam
pressures to 50 psi and liquid medium pressures to
100 psi. However, welded type jackets, specially
fabricated,arealsoavailableforhigherpressures.
2-4.5. Heat Exchanger
Similar to the water jacket in every respect except
for the provision of corrosion resistant tubing, heat
exchangers, whether removable, or welded-on, are
providedonChempumpsinapplicationsthatrequire
heating or cooling the fluid before it enters the rotor
chamber. Heat exchangers are especially
recommended for liquids with low specific heat
characteristics.
All NC Series Chempumps can be provided with
removable wrap-around heat exchangers when
specified. This type jacket is easily removable from
the stator band to allow for inspection and possible
replacement. These heat exchangers are suitable
for maximum inlet pressure of 50 psi and maximum
temperature of 150oF.
Welded on heat exchangers are available on all NC
Series Chempumps. These heat exchangers are
suitable for steam pressure to 50 psi and liquid
medium pressures to 100 psi. Maximum
temperatures vary depending upon existing motor
insulationandTCOsettingasindicatedonthepump
nameplate
2-4.6. Internal Circulation
Internal Circulation is available on all NC Series
pumps. A unit modified for internal circulation
requires the elimination of the circulation tube,
fittings and discharge filter. Internal flow paths are
provided to direct the fluid circulation through the
motorandbearings.
NOTE: Please contact the factory prior to any
modification to internal circulation.
Page 2-7

Table 2-3. Electrical Wiring Data for 230 Volt, 3 Phase, 60 HZ NC Series Chempump
Table 2-4. Electrical Wiring Data for 460 Volt, 3 Phase, 60 HZ NC Series Chempump
Table 2-5. Electrical Wiring Data for 575 Volt, 3 Phase, 60 HZ NC Series Chempump
NOTES:
1.) SELECT CLASS 10 HEATERS BASED ON START KVA WITH A 12 SECOND MAX TRIP TIME.
2.) ( ) INDICATES REDUCTION IN SWITCH SIZE WHEN DUAL-ELEMENT FUSES ARE USED FOR MOTOR BRANCH
CIRCUITS.
3.) (EXCEPT WHERE NOTED), THE SWITCH SIZES ARE THE SAME FOR ALL TYPES OF FUSES.
4.) CURRENT RATINGS BASED ON THREE CONDUCTOR 75O C INSULATED COPPER WIRE AT 30OC AMBIENT
5.) INDUCTION MOTOR, SYNCHRONOUS SPEED 3600 RPM
MOTOR
SIZE SWITCH SIZEAMPS BREAKER SIZEAMPS STARTER NEMA SIZE CONDUCTOR SIZE FOR
MOTORLEADS
CONDUIT
SIZE FOR
MOTOR
LEADS ONLY
CONDUIT
SIZE FOR
MOTOR,PB
AND TCO
LEADS
FUSESIZE,
CODEAND
CURRENT
LIMITING
AMPS
FUSESIZE
DUAL
ELEMENT
AMPS
MAX
SETTING OF
TIMELIMIT
PROTECTION
N1 100 (60) 30 1 10 3/4" 1" 55 40 24.0
N2 100 (60) 60 2 8 1" 1" 95 65 42.8
N3 200 (150) 100 4 4 11/4" 11/4" 165 110 72.5
N4 200 (150) 125 4 2 11/2" 11/2" 225 155 101.2
N5 400 (200) 200 4 2 / 0 2" 2" 335 235 153.9
MOTOR
SIZE SWITCH SIZEAMPS BREAKER SIZEAMPS STARTER NEMA SIZE CONDUCTOR SIZE FOR
MOTORLEADS
CONDUIT
SIZE FOR
MOTOR
LEADS ONLY
CONDUIT
SIZE FOR
MOTOR,PB
AND TCO
LEADS
FUSESIZE,
CODEAND
CURRENT
LIMITING
AMPS
FUSESIZE
DUAL
ELEMENT
AMPS
MAX
SETTING OF
TIMELIMIT
PROTECTION
N1 60 (30) 20 1 12 3/4" 3/4" 30 20 12.0
N2 100 (60) 30 2 10 3/4" 3/4" 50 35 22.6
N3 100 (60) 50 2 8 1" 1" 80 55 36.3
N4 200 (100) 90 3 6 11/4" 11/4" 110 80 50.6
N5 400 (150) 125 4 4 11/2" 11/2" 175 120 77.0
MOTOR
SIZE SWITCH SIZEAMPS BREAKER SIZEAMPS STARTER NEMA SIZE CONDUCTOR SIZE FOR
MOTORLEADS
CONDUIT
SIZE FOR
MOTOR
LEADS ONLY
CONDUIT
SIZE FOR
MOTOR,PB
AND TCO
LEADS
FUSESIZE,
CODEAND
CURRENT
LIMITING
AMPS
FUSESIZE
DUAL
ELEMENT
AMPS
MAX
SETTING OF
TIMELIMIT
PROTECTION
N1 60 (30) 20 1 12 3/4" 3/4" 20 15 9.6
N2 100 (60) 30 2 10 3/4" 3/4" 40 30 18.0
N3 100 (60) 60 2 8 1" 1" 65 45 29.0
N4 200 (100) 60 3 8 1" 11/4" 90 65 40.5
N5 200 (150) 100 4 2 11/2" 11/2" 135 95 61.6
Page 2-8

SECTION 3. OPERATION
a) Useaphasesequencemeterontheelectrical
connections. The readings from the phase
sequencemeter canbecheckedagainstthe
phasesequenceindicatedontheChempump
nameplate.
b) AftertheChempumpisproperlyprimed and
vented, start the unit with the discharge
pressure valve almost closed. Note the
discharge pressure at a pressure gauge
whichshouldbeinstalledbetweenthepump
casing and discharge valve. Reverse any
two of the three power leads and read the
pressure gauge again. The higher pressure
is the correct direction of rotation. It is
recommendedthattheunitberunaslittleas
possible with a closed discharge valve in
order to prevent excessive overheating of
the fluid circulating within the unit.
NOTE
If a discharge valve is not available
analternatemethodistouseaflow
meter and determine higher flow
rate. Wrong direction of rotation is
indicated by a low discharge
pressure or flow rate. At shut-off,
head is about 2/3 of the head
produced by correct rotation.
Continued operation in reverse can
result in the impeller’s becoming
loose or completely detached from
the rotor shaft. If reverse rotation
has occurred, it is wise to shut
down the unit and tighten the
impeller nut before restarting.
3. Tag correctly connected main power leads, in
accordance with motor lead markings.
3-4. Starting Procedure
After priming and checking the direction of rotation,
put the pump in operation as follows:
1. Almost close the valve in the discharge line.
2. Fully open the valve in the suction line.
3. Start the pump.
4. When the pump is running at full speed, slowly
open the valve in the discharge line to the
desired setting.
3-1. Procedure Before Initial Start-up
Beforestartingthepumpforthefirsttime,makesure
suction and discharge piping are free of tools, nuts,
bolts, or other foreign matter. Save time and money
by checking before start-up.
RECOMMENDED: Install a temporary 3/16" mesh
screen near the suction port to trap scale and other
foreign particles. The screen can be installed for 24
hours of operation, but watch closely that the pump
does not become starved for fluid because of a
clogged screen. REMOVE SCREEN AFTER 24
HOURS OF RUNNING.
3-2. Priming and Venting
Thepumpmustbeprimedbeforeoperating.Priming
requiresthefillingofthepumpcasing,rotorchamber
and circulation tube with system fluid.
When there is a positive suction head on the pump,
priming can be accomplished by opening the valves
in the suction and discharge line, and allowing the
pump casing, rotor chamber, and circulation tube to
fill.TheNCSeriesiscenterlinedischargeandisself-
venting.
3-3. Rotation Check
Centrifugalpumpimpellers mustrotateintheproper
direction to deliver rated head and capacity. The
impeller must rotate in the same direction as the
arrow cast in the pump casing. All new Chempumps
are supplied with a Direction of Rotation Indicator.
Refer to section 2-3.5, Page 2-5, for a complete
description of the D.R.I.
If your pump is not equipped with a Direction of
Rotation Indicator correct rotation can be checked
as follows:
1. Wire Chempump motor for correct voltage.
2. With main power leads connected, check
direction of impeller rotation. If the unit is not
installed in the system rotation can be observed
by “bumping” the motor and looking into the
suction flange. NEVER LOOK INTO THE
DISCHARGE FLANGE. If direction of impeller
rotation is incorrect, change two power leads. If
the pump is installed and primed, the impeller
rotation can be checked by one of two ways:
Page 3-1

CAUTION
The pump should not be allowed to
run for more than one minute with
the discharge valve fully closed.
NOTES:
1. Ifthesuctionanddischargelinesarecompletely
filled with system fluid and adequate suction
head is available, the pump can be started
without closing the discharge valve. During any
start up sequence, caution must be exercised
not to exceed full load ampere rating indicated
on the nameplate.
2. If the unit has not been run for a period of two
weeks or more, the following inspections shall
precede its operation:
a) Check terminal box for moisture.
b) Upon starting, check for excessive noise,
vibration, erratic speeds or excessive amp
draw.
CAUTION
Ifthepumpappears tobeairbound
as a result of the unit not being
properly primed, do not continue
operation. Locate and correct the
conditions that prevent proper
priming before attempting to start
the unit.
3-5. Operation Details
Discharge pressure should be checked frequently
during operation. Pressure should be stable in a
non-variable closed loop although the discharge
pressure gauge needle may show small fluctua-
tions.
In some cases, the fluid supply may contain an
excessive amount of air or gas which will tend to
separatefromthefluidandremaininthepassageof
the pump. This results in the pump losing its prime
and becoming air bound with a marked reduction in
capacity. The discharge pressure gauge will show
large fluctuations if this occurs.
3-6. Shutdown Procedure
Shutdown is as follows:
1. Close the valve in the discharge line.
2. Stop the pump (De-energize the motor).
3. Close suction valves if pump is to be removed
from service.
CAUTION
If the pump is to be shut down for a
long period of time or if there is
danger of freezing, after stopping
the pump, shut all suction and
discharge valves, and drain the
entire pump and connecting piping.
NOTE:
To assist in determining remedies for various
problems, see Table 4-3, Page 4-7, Trouble
Shooting.
Page 3-2

SECTION 4. MAINTENANCE
4-1. Periodic Inspection
Initial inspection of the unit must be made at 1500
running hours or three months, whichever occurs
first after initial starting. Subsequent inspection
periods will be dependent on the wear rate as
indicatedinParagraph4-3,Page4-2,butinnocase
should any inspection period extend beyond three
years. Each inspection should include attention to
thepointsnotedineachofthefollowingparagraphs.
To assist in determining remedies for pumping or
operation problems see Table 4-3, Page 4-7,
Troubleshooting.
4-1.1. Recommended Tools for Disassembly
and Reassembly
Size (inches) Description
9/16" Open end wrench for circulation
tube fittings.
3/4" and 15/16" Open end, box end wrench for
pump casing and adaptor bolts.
3/4" Open end, box end wrench for
rear bearing housing bolts and
pump casing drain bolts.
1 3/8" Spanner wrench with 1/8" pin for
shaft sleeve retainer.
3/4" Socket wrench for impeller nut
(N1 and N2 motors).
1 1/8" Socket wrench for impeller nut
(N3 and N4 motors).
1 5/16" Socket wrench for impeller nut
(N5 motors).
1/2" and 9/16" Open end, box end wrench for
base cradle bolts.
1/8" Allen wrench for bearing retainer
screws.
Wheel Puller To assist in the removal of the
impeller assembly.
4-1.2. Recommended Tools for Inspection
1. Dial Indicator (.200" travel) for determining end
play.
2. Verniers and 5/16" to 3" telescopic gauges for
inspection of bearings, I.D. shaft clearance
hole, and O.D. of rotor shaft journals.
4-2. Disassembly
1. Close discharge valve, shutdown pump, and
then close the suction valve.
2. Disconnect the power cables from the
connection box prior to disassembly.
(WARNING: SAFETY HAZARD TO PERSON-
NEL WILL EXIST IF THIS STEP IS NOT
FOLLOWED.)
3. Drain pump and connecting piping.
NOTE: If drains are supplied, the NC Series is
designed to drain the majority of fluid in the pump
and motor, however a small amount of fluid will still
bepresent.Also,ifthe pump is equippedwithaheat
exchanger some of the process fluid may remain in
the tubing. Follow your plant safety regulations for
flushingandneutralizingthefluidinthepumppriorto
disconnecting pump from the piping.
4. Begin disassembly, carefully examining each
part for corrosion or wear.
5. Remove circulating tube, back flush piping, or
reverse circulation piping if so equipped.
6. Remove water jacket cooling inlet and drain
connections, if used.
7. Remove bolts holding motor section to pump
casing.
8. The base on the NC Series is designed with
elongatedslotsformountingtoastandardANSI
baseplate.Removetheboltsonthebasesothat
themotorsection,includingtheimpeller,canbe
moved backward to clear the pump casing. The
complete motor section can be rotated for
maintenanceinthefieldortransportedto awork
area for disassembly. If the base is directly
bolted to a concrete pedestal with anchor bolts,
this feature is not available and the motor
section must be lifted off the anchor bolts for
proper maintenance and disassembly.
9. Remove the bolts holding the rear bearing
housing to the stator assembly and remove the
housing.
10. Removethescrewholdingtherearbearinginthe
rearbearinghousingandremovetherearbearing.
Page 4-1

11. Removetheimpellernut(Right-handthreadsare
standard).Thenremovetheimpeller.
12. Withdraw the rotor assembly from rear of motor
section taking care not to allow rotor to drop,
allowing shaft to hit stator liner.
13. Removetheboltsretainingthe motoradapterto
the stator assembly, and remove the adapter.
14. Remove the screw holding the front bearing to
the front bearing housing, then remove the front
bearing.
15. A check for bearing and shaft sleeve wear can
bemadeatthistime.RefertoTable4-1,Page4-
3.
16. If shaft sleeves and/or thrust washer shows
scoring or wear, remove them as follows:
a. Removetheshaftsleeve retainerintherear
with a spanner wrench (Do not use a pipe
wrench). Note: This is a left hand thread.
b. Pull the shaft sleeve off the shaft. Sleeves
are centered with “o” rings which may
present some resistance. If so, pull on the
thrust washer which should easily move the
sleeve ahead of it.
c. Remove key.
d. Remove “o” rings from the shaft.
e. Thefrontshaftsleeveandthethrustwasher
are retained by the impeller which has
already been removed. Follow steps b. thru
d. for the removal of these items.
4-3. Inspection
4-3.1. Bearing Inspection
Sincethebearingsinthispumparelubricatedbythe
process fluid, it is essential that bearing inspection
andreplacementperiodsbebasedonexperiencein
each particular installation. Bearing life will depend,
to some extent, on variable factors including
lubrication quality, temperature, number of starts
and stops, viscosity, and suspension content of the
fluid being pumped, as well as ambient temperature
and atmospheric conditions of the operational area.
Each time one of these factors is changed,
compensationmustbe appliedinbearing inspection
periods.
Initialinspectionofthebearingsshouldbescheduled
at 1500 running hours, or three months, whichever
occurs first after initial starting. This inspection is
necessary to determine the rate of bearing wear,
therebyenablingthesettingupofaproperinspection
andreplacementschedule.SeeTable4-1,Page4-3,
forthemaximumwearallowable.
If the inspection indicates that bearings are not
wearing or are wearing very slightly, the next
inspection may be put off for an additional 1500
running hours, or three months of operation,
whichever occurs first. If inspection, then, still
indicates only slight wear, the interval may be
lengthened.
If, however, bearings must be changed at the initial
inspection,theywillneedto be changedagaininthe
timeperiodwhichnecessitatedachangeattheinitial
inspection, i.e., 1500 running hours.
Frequency of periodic bearing inspection can best
be determined by experience. From these
inspections the time for replacement can best be
indicated.
Bearings can be inspected and replaced without
removing the pump casing from the line. No main
piping connections need be broken.
To examine for bearing wear:
1. Measure the inside diameters of the front and
rear bearings and compare with the diameter of
the rotor shaft sleeve. If the difference in
diameters is greater than that indicated in Table
4-1, Page 4-3, replace the bearings.
2. Inspect the thrust faces of the front and rear
bearings. If any scoring wear is visualized,
measurethelengthofthebearings.Replacethe
bearing if the measured length is less than that
indicated in Table 4-1.
3. Examinethebearingsforanygroovingorscoring,
particularly on the inside diameter and thrust
faces.
Page 4-2

The existence of grooving or scoring indicates the
presence of solids or foreign matter in the system
which should be eliminated prior to again beginning
operation. Grooving or scoring may also occur if the
bearingsarerunwithoutlubrication.
4-3.2. Automatic Thrust Balance and End Play
Inspection
The provision of automatic thrust balance design in
the NC Series Chempump, with its close running
seal faces and wearing rings to insure proper
balancechamberpressures,requiresthatadetailed
visual inspection be made of the impeller, front
bearing housing, front and rear thrust washer and
the pump casing, at the time of bearing inspection.
Duringdisassemblyforbearinginspection,measure
theunitendplayandcomparewiththefollowingvalue:
MODEL MOTOR END PLAY
SIZE (INCHES)
ALL ALL 0.072 to 0.096
(0.17 to 0.24 Cm.)
If the end play exceeds the maximum allowable
movement, then the bearings and/or thrust washers
are worn and must be replaced. (It should be noted
that under proper operating conditions, wear on
these parts due to axial thrust forces will be
negligible).
4-3.3. Rotor Assembly Inspection
The complete rotor assembly should be visually
inspected for cracks, breaks, pitting, or corrosion
which might destroy the effectiveness of the
hermetically sealed rotor end covers and sleeve.
The rotor assembly shaft sleeves and thrust
surfaces should also be visually inspected at the
bearing contact area for general appearance and
uniform wear. Excessive undercutting, pitting, or
scoringiscausefor replacement.Minimumallowable
shaftsleevediameterisnotedinTable4-1.
4-3.4.StatorAssemblyInspection
The complete stator assembly should be visually
inspected for cracks, breaks, pitting, or corrosion of
thestatorlinerwhichmaydestroytheeffectivenessof
thebarrier.Inspectthewiringbycheckingthevisible
portionoftheconnectorleads forcracked,brokenor
frayed insulation. Check the condition of the motor
windings by comparing the ohm meter values with
thoseshownon Table4-2,Page 4-6.
4-3.5. General Inspection
1. Inspect the impeller nut threads on the rotor
shaft to ensure they are not damaged. NC
Series Chempumps have right hand threads.
2. Be sure that all mating faces are free of nicks
and burrs so that they will have a smooth face
ensuring a good seal. Clean off any trace of old
gasket material.
3. Make sure all parts are clean. Inaccessible
areas may be cleaned with a small brush or
pointed tool. The circulation line should be
blown out with filtered, oil free, compressed air.
4. The impeller face should be inspected for wear.
If excessive grooving or scoring of the wear
ringsisevident, theimpellermustbe repairedor
replaced.
4-4. Reassembly
1. Reassemble pump by reversing the disassem-
bly procedure. Replace all worn or corroded
parts, and “o” rings throughout the pump.
a. Before reassembly of the shaft sleeves and
thrust washers, clean the shaft of dirt,
corrosion products, or residue.
b. Put the thrust washer on the shaft.
c. Insert key
d. Put “o” rings on shaft.
e. Slideshaftsleeveonshaft,engagingthekey,
until it is seated against the thrust washer.
f. Replace the retainer in the rear and the
impellerinthefront.
Table 4-1 NC Series Bearing and Journal Dimensions
MODEL UNIT SHAFTSLEEVE BEARING diametrical MAX. LENGTH
OUTSIDEDIA. INSIDEDIA. CLEARANCE ALLOWABLE
All Inches 1.6220-1.6213 1.626-1.627 .004 - .0057 .014 3.0
All Cm. 6.38 6.4 .02 0.055 11.8
Page 4-3