Tsurumi Pump 3PN Installation instructions

1

Tsurumi
3PN (50PN2.25S)
4PN (50PN2.4S)
8PN (50PN2.75S)
Maintenance, Inspection & Overhaul
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OVERHAUL MANUAL
3PN - 4PN – 8PN
The following is a guideline for the inspection
and overhaul of the PN Series water feature
pumps. Use this guide, along with the parts
list, exploded view diagram, and operation
manual for your particular pump model to
disassemble, inspect, and rebuild your pump
to factory conditions.
Replacement parts can be purchased through
our dealers and distributors network or
online at www.tsurumipumpstore.com
If there are any questions, feel free to
contact us at [e-mail].
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Sections
Insulation Resistance Testing Page 6
Inspect Oil Chamber Page 11
Inspect Pump Casing Page 13
Inspect Mechanical Seal Page 16
Motor Inspection Page 25
Pump Re-Assembly Page 34
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Tools Required
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Insulation Resistance Testing
Testing the resistance of a motor’s insulation system with a megohmeter
(megger) ensures that the motor is not internally shorted, which can
cause damage and/or injury. Check the pump’s maintenance manual
for recommended testing intervals.
6

Megger Test motor
Set your Megger Tester to 2X the motor’s
rated voltage (250V in this instance), and
attach the testers red lead to one of the plug
spades, and the testers black lead to the
ground prong. Press the TEST button on the
Megger and record readings after 20
seconds. Repeat test with the other plug
spade to ground.
Resistance values between 20 MΩand 1 MΩ
indicate that the insulation system is starting
to fail. Readings under 1 MΩafter 20
seconds indicate a shorted motor, and the
unit cannot be economically repaired.
If any reading is less than 20 MΩ, test motor
and cable separately to isolate the problem
to either the cable or the motor.
If the problem is in the cable, replace cable
and re-test. If MOTOR resistance is less than
1 MΩ, there is evidence that the motor is
damaged, and the motor should not be
used. Further disassembly and inspection
will be necessary.
7

Cable Inspection
Measure and inspect pump cable. Note total
length of cable. Cables, as supplied, are 20’
in length (older units are 32’).
If there are any cuts or other deformities in
the cable, or the cable is less than 20’ in
length, the cable should be replaced.
Inspect cable plug for damage and ensure
that grounding prong is intact for safe
operation.
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9

Cable Assembly
Removal
Using an 8mm socket or Phillips screwdriver,
remove the two bolts securing the cable
gland to the head cover.
CAUTION: If water has worked it’s way into
the motor area, this can be under pressure
and water can spray out. Wear eye
protection.
Carefully wiggle the cable assembly out of
the motor casing and inspect the
connections. If there is oil and/or water
present in this area, the motor assembly will
need to be disassembled for inspection and
repair.
Disconnect the three bullet connectors that
connect the cable to the motor stator and set
cable aside.
10
Bullet
Connectors

Inspect Oil Chamber
Tsurumi recommends to inspect the oil every 6 months of operation. If
there is water in the oil chamber or the oil level is low, this is evidence of
a worn mechanical seal, which should be replaced before irreparable
damage occurs.
11

Drain and inspect oil
To drain the oil, locate and remove the hex
bolt located on the oil casing, on the side of
the pump.
Oil casing may be under pressure, so be sure
to wear eye protection, and shield the oil
from spraying everywhere.
Drain the oil into a clear, graduated
container. Inspect oil and record volume.
There should be 5.2 oz of clean oil in the oil
chamber. Water or foreign debris in the oil
indicate that the mechanical seal has leaked
and needs to be replaced. If the oil contains
no water, simply replace with fresh oil and
reassemble unit.
If further disassembly will be performed,
insert the hex bolt back into position and
tighten, in order to prevent dripping.
Reference page 51 for oil replacement after
disassembly.
12
Hex Bolt
Oil Casing

Inspect Pump Casing for
wear and/or debris
If your pump is running but is not performing as new, there could be
wear to the impeller or foreign debris stuck in the strainer or pump
casing.
13

Remove Pump Casing
Using a 10mm socket, remove the hex screws securing the pump casing. With the pump casing removed, inspect the pump casing,
impeller, and discharge flange for wear and damage. Any worn components should be replaced to regain original performance of the
pump. Remove any foreign debris from the wet end.
14
Pump Casing
Impeller

Remove Impeller
With a #2 Phillips screwdriver bit on a
cordless impact driver, remove the
screw securing the impeller. It may
be necessary to hold the impeller in
place with pliers while unfastening
the screw.
Remove the impeller and set aside.
15

Inspect/Remove Mechanical
Seal
If oil or debris was found in the oil chamber, or oil level is low, it is
necessary to change out the mechanical seal.
16

Remove Oil Casing
If there is evidence that mechanical seal is
leaking (water or debris in the oil or motor
has failed the Megger test), it will be
necessary to remove the oil casing from the
motor frame.
Using a 5mm hex bit, remove the (4) bolts
securing the oil casing.
Once these are separated, oil WILL leak out.
17
Oil Casing

Inspect oil casing,
O-ring, oil lifter, and
mechanical seal.
It is recommended to use only new packings
and O-rings upon re-assembly, so O-ring will
NOT be re-used. Check for debris, or grit in
the oil chamber, and make sure oil lifter is
not cracked or otherwise damaged. This
chamber will need to be flushed and
thoroughly cleaned if water or debris is
present.
18
Mechanical
Seal

19

Remove oil lifter to
expose stationary seal.
The oil lifter is press-fit into the oil casing.
Carefully lift this off to allow removal of the
stationary portion of the mechanical seal.
20
Oil Lifter