IWAKI AMERICA MDE Series User manual

IWAKI AMERICA
MAGNETIC DRIVE PUMP
MDE SERIES
INSTRUCTION MANUAL

Contents
Item Page
1. Unpacking and Inspection ................................................................................... 3
2. Identification ........................................................................................................ 4
3. Specifications ...................................................................................................... 5
4. Handling Instructions ........................................................................................... 6
5. Installation,PipingandWiring ............................................................................. 7
6. Pump Operation ................................................................................................ 12
7. Maintenance and Inspection.............................................................................. 14
8. TroubleshootingGuide ....................................................................................... 18
9. Parts Description and Exploded View............................................................... 22
10. Disassembly andAssembly of Pump (close-coupled motor type)..................... 24
11. Disassembly andAssembly of Pump (frame mounted motor type) .................. 32
12. Spare Parts........................................................................................................ 41
13. ExternalDimensions and Weights ..................................................................... 42
Thank you for having selected an Iwaki America MDE Series magnetic-drive pump.
This instruction manual deals with the correct handling, maintenance, inspection, and
troubleshooting procedures for the MDE magnetic drive pump. Please read through it
carefully to ensure the optimum performance, safety and long service of your pump.
P/N 180125 Rev. C 5/01

3
Unpacking and Inspection
Open the package and check that the product
conforms to your order. Also, check each of the
following points. If there is a problem or discrep-
ancy, contact your distributor at once.
1. Check that the model, head, capacity, material,
motor output and voltage indicated on the
nameplate conform to the specifications of your
order.
2. Check that all the accessories you ordered are
included.
3. Check that the pump body and parts have not
been accidentally damaged nor any bolts and
nuts loosened in transit.
1
MODEL MDE-
HEAD (FT.)
CAPACITY (GPM)
IMPELLER DIA.
MAT. OF CONST.
OPTIONS
SERIAL NO.
HOLLISTON, MA 01746
IWAKI WALCHEM
MAX. DSGN PRESS. @ 38°C (100°F)
HP 60 Hz.
MAX.
RPM
PSI
IWAKI AMERICA

4
Identification
nModel Code
1 2 3 4 5 6 7
MDE AA 6PKC07
1. Series Name
2. Pump bore symbol (suction ´discharge)
AA: 1 ½ ´1
AB: 3 ´1 ½
3. Impellernominal size
6: 6 inch
8: 8 inch
4. Materials of wetted parts
(portions made of resin)
P: PFA
E: ETFE
5. Bushing material
K: SiC
6. Motor type
C:Frame mounted type motor
F:Flange type motor (close-coupled)
7. Magnet Coupling Rating (@ 3600 RPM)
05: 5 HP 15: 15 HP
07: 7 ½ HP 20: 20 HP
10: 10 HP 25: 25 HP
Options
Nocode: Without option
1: With leak sensor
2: With bearing temperature monitor
3: With bearing creep sensor
4: With bearing flusher
9: With two or more options
2

5
Specifications
3600 RPM / 60 Hz
Connections Head Rated Capacity
Model Inlet x Outlet feet gal/min
AA6 1 ½" x 1" 125 75
MDE AA8 250 100
AB6 3" x 1 ½" 125 150
Notes:
1. Standard performance (head/capacity) represents the maximum discharge quantity measured with
pure water at 68° F.
2. Liquid temperature range:
PFA type ... 32~248° F
ETFE type ... 32~212° F
3. Slurry: Hardness 80Hs or below, grain size maximum 2 mil (50 microns), density maximum 5% wt.
Contact IwakiAMERICA or your distributor for details.
nMaterials of main components
3
Material
Part EP
1. Casing Liner
2. Casing Cover
3. Impeller ETFE PFA
4. Magnet
Assembly, inner
5. Containment
Shell
6. Gasket PTFE
7. Bushing,Bearing
inboard
8. Bushing,Bearing
outboard SiC
9. Thrust Collar
inboard
10. Thrust Collar
outboard
11. O-ring Kalrez®

6
Handling Instructions
1. Do not operate the pump dry.
The sliding parts used in the MDE series pumps are lubricated and cooled by the fluid being pumped.
Never operate the pump dry or with the valves on the suction side closed. Otherwise, the inside of the
pump will be damaged. If the pump is unavoidably or accidentally operated dry, with no obvious
damage, allow the pump to cool down for a minimum of one hour before attempting to restart. Do not
allow fluid to enter the pump cavity until the pump has cooled down. Sudden or rapid cooling of the
pump may cause severe damage to the ceramic bearing system. A dry run device is recommended for
the prevention of dry pump operation.
2. Points to be observed upon starting and stopping pump operation.
Pay close attention to the following points to avoid water hammer upon starting and stopping pump
operation. Extra attention is required when the discharge piping is very long.
Starting
Prior to starting the pump, make sure that the power is turned off. Then carry out priming to fill the
pump cavity with liquid. After priming is completed, rotate the coupling (or motor fan) by hand (five
rotations or so) to expel air remaining in the impeller and bearing system of the pump.
Caution
Manually rotate pump drive shaft before start up to ensure ventilation of entrapped air. Failure to do
so may result in damage to the pump bearing system.
Next, close the valves on the discharge side. Now you can turn power on and start up the pump.
When the pump has reached full speed and line pressure is stable, the discharge valving can be opened
to the desired settings.
Caution
If the pump is operated with air remaining in the pump cavity, biting, cracking or breakage of the
bushing and/or thrust collar may occur, causing damage to the pump.
Stopping
When stopping the pump, first close the discharge
valve gradually. When it is completely closed, turn
off the power switch so that the pump stops.
Never stop the pump suddenly by quickly closing a
valve (i.e., solenoid or hydraulic valves).
Caution
Quick valve closure may cause water hammer
which can cause severe damage to the pump.
3. Maximum pressure rating.
The table on the right shows the maximum
pressure rating for each model. Take care that
4

7
the discharge pressure does not exceed the maximum pressure rating.
Contact IwakiAmerica or your distributor for the pressure rating of your pump if you are using an
external flush, casing drain or monitoring options.
4. Handlingofslurryliquid.
In general, slurries should not be handled. If the density is 5% wt or less and the grain size is 2mil
(50 microns) or less, however, pumping is possible. Prior to pumping such slurry liquid, you should call
IwakiAmerica or your distributor to verify if the operation is feasible.
5. Influence of specific gravity on pump performance.
The performance of the pump does not change even for liquids of higher specific gravity. However, a
magnet assembly and motor selected for the specific gravity should be used.
6. Influence of liquid viscosity on pump performance.
When pumping a high viscosity fluid, the discharge head and capacity of the pump may be lower than
in the case of pure water. The required driving power may also vary and should be checked.
7. Intermittentoperation.
Frequent start/stop switching considerably shortens the service life of the pump. Limit the frequency
of switching to six times per hour.
8. Influence of temperature.
The pump itself may not suffer a change in performance due to temperature fluctuation. However, the
liquid may change in terms of viscosity, vapor pressure, and corrosive resistance. Pay special attention
to changes in liquid characteristics as a result of temperature fluctuation.
Installation, Piping and Wiring
nInstallation position
1Install the pump as close to the suction tank as possible (flooded suction). If the suction port of the
pump is positioned higher than the suction tank (suction lift), be sure to arrange a foot valve in the
priming pipe and suction pipe. The lifting capability depends upon the liquid properties, temperature,
and length of suction piping. For details, consult IwakiAmerica or your distributor.
2. The pump can be installed for use indoors or outdoors. However, there should be sufficient space
around the pump to enable efficient and easy maintenance.
nInstallation
1. The pump anchoring area must be greater than the area of the base. If the anchoring area is not large
enough, the base may be damaged due to the concentration of loads placed on it.
2. Set the pump base on a concrete foundation and fasten the anchor bolts tightly to prevent the pump
fromvibrating during operation.
5

8
3. Insert a spacer between the concrete surface and the bottom of the base to level the pump horizon-
tally. Next, put a level on the discharge flange surface to adjust the pump horizontally in the direction
of the pump shaft. Also adjust the direction vertical to the pump shaft at the same time by placing a
level on the suction flange surface. Pour cement mortar into the foundation bolt holes after leveling
has been completed. When the cement mortar is hardened, fasten the anchor bolt nuts firmly. (See
Fig. 1)
4. In case there is influence of motor vibration
during operation(e.g., sympathetic vibration
withpiping), an expansion joint should be
provided between the pump and the piping
before the installation. Otherwise, pipes and
gauges may be damaged.
nPiping 1. Discharge pipe (Use a support to keep
the pump free from the load of the
pipe.)
2. Discharge valve.
3. Check valve.
4. Pressure gauge.
5. Motor.
6. Pump.
7. Priming pipe.
8. Gate valve.
9. Drain ditch.
10. Compound gauge.
11. Suction pipe (Diameter = D) (shortest
horizontal section with an ascending
gradient toward the pump).
12. Pipe support.
13. Pump drain.
14. Suction pipe (D: diameter of pipe).
15. Suction pipe stabilizer brace (Used if
thesuction pipe isparticularly long.)
16. Foot valve.
17. 1.5D or more.
18. 2D, or 24 inches or more.
19. 1~1.5D or more (if sediment accumu-
lates easily).
20. Suction tank.
21. Screen.
22. Short pipe.
Base
Anchor bolt
Spacer

9
nSuction Piping
1. The suction pipe should employ the flooded suction method if possible. The shortest pipe possible, with
a minimum number of bends, should be designed. Arrange a proper support along the suction pipe so
that the load and thermal stress of the pipe itself are not applied to the pump.
2. Attach the coupling on the suction pipe carefully so that no air enters the line. Air in the suction pipe
may prevent priming of the pump.
3. If the suction condition is not good (e.g. the suction tank is a vacuum, the suction head is large, or the
suction pipe is long), NPSHa should always be at least 2 feet greater than NSPHr. For the NPSHr,
refer to the Standard Performance Curve.
4. When a bend is used on the suction side, install a straight pipe which is more than 20 inches long or 10
times as long as the suction port diameter before the suction port of the pump. Use the largest possible
radius of curvature for the bend.
5. Do not allow any projection where air may be trapped along the suction pipe. The suction pipe should
have an ascending gradient toward the pump.
UNACCEPTABLE CONDITIONS
AIR TRAP
AIR TRAP
AIR TRAP
AIR TRAP
GOOD CONDITIONS

10
6. If the diameters of the pump suction port and suction pipe are different, use an eccentric reducer pipe.
Connect the eccentric reducer pipe such that the upper part of it is level. Never use a suction pipe
with a diameter smaller than that of the pump suction port.
7. When using the flooded suction method, the suction pipe should be given a slight ascending gradient
toward the pump so that no air pocket is created on the suction side.
8. The end of the suction pipe should be located 24 inches or more below the surface of the liquid.
9. A screen should be provided at the inlet in the suction tank to prevent the entry of foreign matter into
the suction pipe. Foreign matter may cause malfunctioning of the pump. The end of the suction pipe
should be 1~1.5D or more away from the bottom of the suction tank. (D: diameter of suction pipe).
10. When using the suction lift method, install a foot valve on the suction pipe.
11. When using the flooded suction method, it is recommended that a gate valve be installed on the suction
pipe to enable easier overhaul inspection of the pump. Since this valve is used only in the overhaul
inspection of the pump, keep it fully opened during normal pump operation.
12. Pay close attention to the lowest level of the liquid in the suction tank so that air entrainment to the
suctionpiping will not occur.
The inflow pipe into the suction tank should be distanced from the suction pipe and positioned
below the liquid surface level as a means of preventing air entrainment to the suction pipe. If air
bubbles are generated in the suction tank, install a baffle.
13. It is recommended to install a vacuum/pressure gauge on the suction piping approximately 6 D from
the pump suction flange.
nDischarge piping.
1. Use proper pipe supports so that the weight of the piping does not load the pump nozzle.
2. If a method other than flooded suction is used, install a special pipe for priming.
3. If the piping is very long, its diameter should be determined by calculating the piping resistance.
Otherwise, the specified performance may not be obtained due to increased piping resistance.
4. A check valve should be installed if any of the following conditions exists in the piping:
• The discharge piping is very long.
• The discharge head is 50 feet or more.
• The end of the discharge pipe is 30 feet higher than the surface of the suction tank.
• Several pumps are connected in parallel with the same piping.

11
5. The installation of a gate valve on the discharge pipe is recommended for the adjustment of discharge
quantity and for the prevention of motor overload. When installing both a check and a gate valve, the
check valve should be positioned between the pump and the gate valve.
6. A pressure gauge must be installed on the discharge piping.
7. An air bleeding valve should be installed if the discharge pipe is very long in the horizontal direction.
8. A drain valve should be installed for the drainage of liquid if there is a chance that the liquid in the
discharge pipe will freeze.
nWiring
Use appropriate wiring materials and abide by the
local and national standards for electrical codes,
and the instruction manual of the motor. In addition,
followthe instructions givenbelow.
1. Use an electromagnetic switch that conforms to
the specifications (voltage, capacity, etc.) of the
pumpmotor.
2. If the pump is installed outdoors, use waterproof
wiring to protect the switches from rainwater
and moisture.
3. The electromagnetic switch and push button
should be installed at a reasonable distance from
the pump.
4. Refer to the wiring example shown on the left.
Thiswiring diagram does notincludethe installa-
tion of a dry-operation prevention device. Refer
to the instruction manual of the dry-operation
preventiondevicewheninstalling it.
5. If the horsepower of your motor is 7 ½ HP or
higher, You can use a motor soft starter if
desired.
MC
M
OLR
MC ON
OFF
RST
POWER
PUSHBUTTON
M
MC
ON
OFF
OLR
MOTOR
ELECTROMAGNETIC SWITCH
OVERLOAD RELAY
PUSH BUTTON

12
Pump Operation
nNotes on operation.
1. Never operate the pump dry or with the suction side valve (gate valve) closed. Otherwise, the pump
will be damaged.
2. In the event of cavitation, stop the pump immediately.
3. If the magnet coupling decouples, stop the pump within a minute. The power of the magnet coupling
will be reduced if operation is continued with the coupling disconnected.
4. Temperature fluctuation should not exceed 176° F throughout the modes of starting, stopping, and
operating the pump.
5. Be sure to close the discharge valve completely before starting operation, in order to prevent water
hammer upon start-up.
6. The pump should never be operated for a lengthy period with the discharge valve closed. A resultant
rise in the temperature of liquid in the pump can cause damage to the pump.
7. In the event of a service power failure during pump operation, turn off the power switch immediately
and close the discharge valve.
nStart-Up Preparation
Preparation should be carried out as described below when operating the pump for the first time or
restarting operation after a long stoppage.
1. Thoroughly clean the inside of the piping and pump. Supply water.
2. Tighten the flange connecting bolts and base installation bolts. Check the torque of the bolts which
couple the liner, casing and the frame together. Proper torque is 58.8N-m (43.4 lb-ft).
3. Use a screwdriver to rotate the motor fan and check that the fan rotates smoothly.
Caution
Manually rotate pump drive shaft to ensure ventilation of entrapped air in pump casing. Failure to do
so may result in damage to the pump bearing system.
4. After priming the pump, close the discharge valve fully.
5. In the case of flooded suction, measure the pressure in the suction pipe to check that the pump is filled
with liquid. Next, rotate the motor fan using a screwdriver, etc., to rotate the pump and remove any air
trapped in the impeller section.
6

13
6. In the case of the suction lift method, simultaneously carry out priming and rotate the motor fan using a
screwdriver, etc., to rotate the pump and remove any air trapped in the impeller section.
7. Run the motor momentarily to check the direction of rotation. The motor should run in the direction
indicated by the arrow sealed on the pump. (Clockwise when viewed from the motor fan side.) If the
direction is reversed, exchange two wires of the three-phase power wires.
nOperation
Following are details of the pump operation procedure.
Check/Operation Item Remarks
1. Check Valve Suctionvalve..fully open
Discharge valve..fully closed
2. Checkpump is filledwithliquid. If pump isnotfilled with liquid, fillit in accor-
dance with steps 5 and 6 of ‘Start-up
Preparation’.
3. Turn ON motor switch momentarily See the arrow on the casing to confirm
and check for correct direction of pump the direction of rotation (clockwise when
operation. viewed from the motor fan side).
4. Flow rate adjustment Openvalve carefully, paying attention to
If total discharge presssure is increased to ammeter to prevent motor from being
shutoff pressure after achieving normal overloaded through excessive opening of
pump operation, open discharge valve valve.
gradually to set discharge pressure as
specified.
Pump should be operated observing following discharge quantity.
Minimum discharge quantity: 13 gal/min. or more.
In case of automatic control, close discharge valve when starting pump and gradually open
discharge valve thereafter.
5. Points to be observed during operation. If flowmeter is unavailable, check values
If pump enters continous operation of discharge, suction pressure, and current
condition, check flow meter and confirm in relation to piping resistance.
that pump operation meets specifications.

14
nStopping Operation
Check/Operation Item Remarks
1. Close discharge valve gradually. Caution
Do not cause sudden closure by using solenoid
valve, etc. Otherwise, pump may be damaged
by water hammer.
2. Stop motor. Observe whether motor stops rotating slowly
and smoothly. If not, check inside of pump.
3. Points to be observed when stopping pump.
Caution
If pump operation is stopped in winter, liquid inside the pump cavity may freeze and
damage the pump. Be sure to drain liquid completely. In case of short-term suspension
of operation, which does not allow removal of liquid, use band heater, etc., to prevent
liquid inside the pump from freezing.
In the event of service power failure, turn OFF power switch and close discharge valve.
Maintenance and Inspection
nDaily Inspection
1. Check that the pump operates smoothly, without generating abnormal sounds or vibration.
2. Check the level of the liquid in the suction tank, and the suction pressure.
3. Compare the discharge pressure and motor current measured during operation with the specifications
indicated on the motor and pump nameplates to verify whether the pump load is correct.
* Note that the indicated value of the pressure gauge varies in proportion to the specific gravity
oftheliquid.
Note:
The valve to the pressure gauge or vacuum gauge on the piping system should be opened only when
measurements are recorded. It must be closed after the completion of each measurement. If the
valve remains open during operation, the gauge mechanism may be affected by abnormal pressure
caused by water hammer, etc.
4. If a spare pump is included in the installation, keep it ready for use by operating it from time to time.
7

15
nPeriodic Inspection
Inspection
Interval Countermeasure
Every 6 mos.
* Inspection
record should
be main-
tained.
Outer
magnet
assembly
Part Name Inspection Point
Is there scoring?
Is housing mounted normally?
Are hexagonal socket
setscrews loose?
Are inner perimeter of magnet
and motor shaft concentric?
(Max. eccentricity: 1/4 mil.)
Contactyour distributor if
abnormality is observed.
Reinstall housing on motor shaft
and fasten hexagonal socket
setscrews.
Retighten or replace
hexagonal socket setscrews.
Every 3 mos.
* Inspection
record should
be main-
tained.
Containment
shell cover
Containment
shell cover
Inner magnet
assembly
Impeller
Is there scoring?
Improperinstallation in frame?
Is there scoring on inner
diameter?
Are there any cracks?
Gasket, outboard
Is there scoring in rear section
orin cylindrical body?
Are there any cracks in resin of
rear section or in cylind. body?
Wear of inboard bearing
bushing?
Wear of inboard thrust collar
Degree of warping of vanes.
Are there any cracks?
Is there clogging cavitation?
Contactyour distributor if
abnormality is observed.
Adjust.
Contactyour distributor if
abnormality is observed.
Replace if abnormality is observed.
Replace if part is damaged.
Contactyour distributor if
abnormality is observed.
Contactyour distributor if
abnormality is observed.
Check degree of wear. Permissible
gap between outboard and inboard
bearing bushing diameter is 40 mil
(0.04in)
Check degree of wear and replace
if required.
Replace if part is damaged.
Replace if abnormality is observed.
Eliminate cause.

16
Inspection
Interval Countermeasure
Every 3 mos.
* Inspection
record should
be main-
tained.
Part Name Inspection Point
Impeller
(continued)
Casing,liner
Casing, cover
Stainor clogging inside
impeller.
Dimensionalchangeofimpeller.
Clogginginbalancinghole.
Stain in liquid-contacting sec-
tion.
Are there any cracks?
Connection with casing cover
(239).
Is drain clogged?
Expansion of gasket or crack in
inboard gasket.
Scoringin inappropriate position.
Stain in liquid-contacting sec-
tion.
Wear of bearing or clogging in
liquidpassage.
Wear of outboard thrust collar,
scoring, or cracking?
Scoringin inappropriate position.
Clean.
Replace if abnormality is observed.
Clean.
Clean.
Replace if abnormality is observed.
Contact your distributor if abnor-
mality is observed.
Clean.
Replace if part is damaged.
Contact your distributor if abnor-
mality is observed.
Clean.
Check degree of wear and replace
if necessary.
Replace if abnormality is observed.
Contact your distributor if abnor-
mality is observed.

17
nWear limit of outboard and inboard bearing bushing.
MDE
Part Name Dimension(inches)
New Upon Replacement
Outboard Bore 1.73in. 1.77 in.
Bearing bushing Thrust face-difference 0.08in. 0.04 in.
Inboard Outer diameter 1.73in. 1.69 in.
Bearing bushing Thrust face-difference 2.52in. 2.56 in.
Note:
If the difference between I.D. of the outboard bearing bushing and O.D. of the inboard bearing
bushing exceeds 40 mil (0.04 inches), replace the bushing, outboard or inboard, whichever is worn out,
with a new one regardless of the value specified in the table.
If abrasion in total exceeds 40 mil (0.04 inches) in thrust face-difference, it also requires replacement.
THRUST FACE DIFFERENCE
I.D. O.D.

18
Troubleshooting Guide
Symptom on Pump
Trouble Cause Inspection and
Countermeasures
With Discharge
Valve Open
Pressure gauge
and vacuum
gauge indicate
'zero'
lInsufficient
priming.
lDry Operation
¡Stop pump, feed priming
liquidand restart pump.
With Discharge
Valve Closed
¡Replace strainer.
¡Check whether seat is
cloggedwith foreign
matter.
lFoot valve is
cloggedwith
foreign matter.
LiquidLevel
dropsimmedi-
ately when
priming is carried
out
lAir enters through
suction pipe or
gasket section.
¡Check whether connec-
tionflange in suction
pipingis sealed airtight.
¡Check whether suction
liquidlevelisabnormally
low.
lMagnet coupling is
disconnected.
¡Stop pump and use a
screwdriver to check for
easy and smooth rotation
of motor fan.
¡Measure current level to
check for low reading.
¡Check for foreign matter
inside pump cavity.
¡Check whether voltage
level is normal.
lRPM of pump is
insufficient.
lPump rotation is
reversed.
¡Check wiring and motor,
and fix as necessary.
¡Correct motor wiring.
Needles of
pressure and
vacuum gauges
swing but return
to zero immedi-
ately.
Liquidleveldrops
if discharge valve
is opened after
starting opera-
tion.
Liquidis
not
pumped
8

19
Symptom on Pump
Trouble Inspection and
Countermeasures
With Discharge
Valve Closed With Discharge Valve Open Cause
Discharge
quantityis
small.
Needles of
pressure and
vacuum gauges
indicatenormal
values.
Needle of
vacuum gauge
indicateshigh
value.
lStrainer is clogged
with foreign matter
andliquid passage
isblocked.
¡Remove foreign matter
in strainer.
Needle of
vacuum gauge
indicatesabnor-
mallyhigh value.
lAir is trapped in
suctionpipe.
¡Inspect installation of
suction pipe and modify
it as necessary.
lInlet section of
impellerunitis
cloggedwith
foreign matter.
¡Partially disassemble unit
and remove foreign
matter.
Needles of
pressure gauge
and vacuum
gauge fluctuate.
lAir enters via
suction pipe or
gasket section.
¡Check flange gaskets of
suction pipe and tighten it
as necessary.
Vacuum gauge
needleindicates
highvalue while
pressure needle
indicatesnormal
value.
lAir pocket or
resistance in
suctionpipe.
¡Inspect suction piping
installationand make
corrective adjustments.
Pressure gauge
needleindicates
highvalue while
vacuum gauge
needleindicates
normal value.
lThere is a section in
discharge pipe that
causes high resis-
tance or actual
head and loss of
head are too high.
¡Check actual head and
piping loss of discharge
pipe and take necessary
measures.
lDischarge side of
pump is clogged
with foreign matter.
¡Remove foreign matter
inpump.
¡Remove foreign matter
or scale inside of piping.

20
Symptom on Pump
Trouble Inspection and
Countermeasures
With Discharge
Valve Closed With Discharge Valve Open Cause
Discharge
quantityis
low.
Needle of
pressure gauge
indicateslow
value and
vacuum gauge
indicates
extraordinarily
low value.
Needle of
pressure gauge
and vacuum
gauge indicate
low value.
lRotating direction of
pump/motoris
reversed.
¡Correct motor wiring to
reverse roation. (Clock-
wise when viewed from
motorside.)
lVoltage is insuffi-
cient.
¡Check whether voltage
and frequency levels are
adequate.
lOverload. ¡Check whether specific
gravity and viscosity of
liquid are above specifi-
cation.
¡Stop pump and use
screwdriver, etc., to
check whether motor
fan rotates easily and
smoothly.
lAmbient tempera-
ture is high.
¡Improve air ventilation.
Discharge
quantityis
suddenly
lowered.
Needle of
vacuum gauge
indicateshigh
value.
lStrainer is clogged
with foreign matter.
¡Remove foreign matter.
Motor
overheats