Pentair MYERS MSP50 User manual

NOTE! To the installer: Please make sure you provide
this manual to the owner of the pumping equipment or
to the responsible party who maintains the system.
OWNER’S MANUAL
MSP50 Submersible Sewage
Ejector Pumps
© 2017 Pentair plc. All Rights Reserved. 23833A705 (09/18/17)
293 WRIGHT STREET, DELAVAN, WI 53115 WWW.FEMYERS.COM
PH: 888-987-8677 ORDERS FAX: [phone]

2
Thank you for purchasing
your Myers®pump. To help
ensure years of trouble-free
operation, please read the
following manual carefully.
Before Operation:
Read the following instructions
carefully. Reasonable care
and safe methods should be
practiced. Check local codes
and requirements before
installation.
Attention:
This manual contains important
information for the safe use of
this product. Read this manual
completely before using this
product and refer to it often
for continued safe product use.
DO NOT THROW AWAY OR
LOSE THIS MANUAL. Keep it
in a safe place so that you may
refer to it often.
WARNING: Before handling
these pumps and controls,
always disconnect the power
first. Do not smoke or use
sparkable electrical devices
or flames in a septic (gaseous)
or possible septic sump.
To reduce risk of electrical
shock:
1. Risk of Electrical Shock:
This pump has not been
investigated for use in
swimming pool areas.
2. Risk of Electrical Shock:
Connect only to a properly
grounded receptacle.
Septic tank is to be vented
in accordance with local
plumbing codes.
Do not smoke or use
sparkable electrical devices
or flame in a septic (gaseous)
or possible septic sump.
If a septic sump condition
exists and if entry into sump
is necessary, then (1) provide
proper safety precautions
per OSHA requirements
and (2) do not enter sump
until these precautions are
strictly adhered to.
Do not install pump in
location classified as
hazardous per N.E.C., ANSI/
NFPA 70 - 2001.
Failure to heed above
cautions could result in
injury or death.
General
Information
Pump
Warning
NOTE: Some city regulations
do not allow installing a
pump with plastic pipe. Check
local regulations.
5. In applications where the
pump may sit idle for months
at a time, it is recommended
that the pump(s) be cycled
every month to ensure the
pumping system is working
properly when needed.
6. Myers check valve
should be installed in
discharge pipe.
7. An audible alarm system
for high water conditions
should be installed in
every pump for greater
protection, such as the Q
Alert for indoor use, rated
NEMA I. For additional
control panels contact your
MYERS distributor.
8. Connect to power source
using 3-prong grounded
AC receptacle. Do not
remove ground pin from
electrical plug. Do not use
an extension cord.
9. Use pump partially or
completely submerged for
pumping waterlike liquids
(temperature to 140°
F). The MSP50 will pump
solid materials up to 1-1⁄2”
(spherical) in diameter.
This pump has not been
investigated for use in
swimming pool areas.
10.Caution: Do not pump
flammable liquids, strong
chemicals or salt water.
Installation
Instructions
These important instructions
must be followed for
satisfactory performance of
your pump. Before installation,
check your local electrical
and plumbing codes.
1. Provide proper sump.
Recommended minimum
sump diameter is 18”.
2. Make sure sump is free of
string, cloth, nails, gravel,
etc. before installing pump.
3. Do not set pump directly on
the bottom of sump if it is
not solid. Raise the pump
by using bricks or concrete
blocks underneath it.
4. Use steel or plastic pipe for
all connecting lines between
pump and sewer outlet.

3
Pump
Servicing
Read the following instructions
carefully before replacing
any parts. Reasonable care
and safe methods should
be practiced. Check local
codes and requirements
before installation. Only
competent electricianshould
make the installations.
Servicing should be performed
only by knowledgeable pump
service contractor or authorized
service station.
Remove from power source.
WARNING: Shock hazard.
1. Checking power cord.
To be sure wires are not
burned off or broken in cord,
use ohmmeter to check. Set
ohmmeter scale pointer to
R x 1 scale and attach one
meter lead to white cord
wire and one meter lead to
black cord lead, then place
screwdriver blade across
blade terminals of plug. If
cord is OK, meter needle
will go to zero and stay
there. If meter needle does
not move, this will indicate
an open wire and cord must
be replaced.
2. Checking motor operation.
When switch cap is off
and switch is removed,
connect two terminals
that were connected to
switch together and tape.
Plug power cord in power
receptacle to check motor
operation. Motor should
start and run smoothly. If
motor does not start, pump
must be dismantled and
motor checked.
CAUTION: Be sure to
unplug cord before continuing
or reassembly if pump
is functional.
3. Checking motor stator.
If motor does not run
when tested as described
above, the stator must be
removed from the housing
and checked. Remove plug
(12) from top of housing,
and pour oil in container,
preferably glass, so that oil
can be observed.
If oil is clear it will indicate
motor is not burned and
there has been no water
leaking into the motor. If
oil is cloudy or black, it will
indicate water in the motor
or a burned stator.
After draining oil, remove
bolts (10) and remove cord
nut (25) from motor cord
(21). Remove rubber seal
ring from around cord. Turn
cord and lift up until seal
ring (26) is removed. Pry
between ears of housing
(24) to remove from base.
Disconnect motor cord from
stator and remove bolts (2)
and plate. Lift stator from
base. If stator is visibly
burned, it must be replaced.
If stator is not burned but
the oil shows signs of water,
stator canbe checked with
the ohmmeter to see if it can
be reused.
4. Ground check.
Set ohmmeter scale pointer
to R x 100K scale and check
meter by putting both meter
leads together and adjusting
the needle knob until meter
reads zero. If meter cannot
be adjusted to zero it will
indicate that batteries in
meter must be replaced.
Check meter to zero and
adjust if necessary before
making any checks on motor.
Now connect one meter
lead to one blade terminal
of stator and touch other
meter lead to motor stator
shell. If needle reads below
5 (500,000 ohms) stator
must be dried out before
rechecking. To dry out, place
Performance Curve

4
motor in 220 degree oven
for four hours. Recheck
after motor cools. If motor
is new or thoroughly dry,
needle of ohmmeter will not
move on the ground check:
This indicates a reading of
50 megohms or higher. One
megohm is one million ohms.
When making the ground
check, if the needle goes
to zero the motor in all
probability has a wire
touching the stator shell at
some point and the stator
will have to be replaced.
5. Winding resistance test. If
motor shows a satisfactory
ground check then the
winding resistance must
be checked. Use ohmmeter
with scale pointer set on
R x 1 scale. On this scale,
meter reads directly on
ohms. Always check the
meter with leads together
as described above, under
ground check, before making
a reading on the winding.
Connect one meter lead to
the terminal with the brown
wire connected underneath
the terminal board. Connect
the other lead to the terminal
housing with the blue wire.
Meter should read 1.2 to 1.4
ohms; this is the resistance
of the main winding for a
115 volt stator. This reading
for a 230 volt stator should
be 4.8 to 5.9 ohms. Now
connect one meter lead to
the brown wire terminal
and the other meter lead
to the red wire beneath the
terminal board. The meter
should read 3.8 to 5.4 ohms
for a 110 volt stator. For a
230 volt stator this reading
should be 16 to 21 ohms.
This is the resistance of the
start winding. Now connect
one meter lead to the red
wire and one to the blue
wire. The meter reading
should be the sum of the
other two readings or 5.0
to 6.8 ohms for a 115 volt
stator or 20.8 to 26.9 ohms
for a 230 volt stator. If the
readings obtained do not
agree with those given, the
stator is defective and must
be replaced.
6. Replacing seal. If water
is found in motor, seal
must be replaced. Remove
bottom casting (5). Place
screwdriver in shaft slot and
tap impeller (6) lightly with
hammer to unscrew. Use
cloth on impeller to prevent
cutting hand. Tap on end
of shaft with a plastic or
rubber hammer. This will
push seal (8,9) from shaft.
Clean case thoroughly;
all sand and dirt must be
removed. Remove stationary
ceramic seat of seal from
housing. Push new ceramic
seat into housing. Use
Parker O-ring lube on
rubber ring. Replace rotor in
housing. Use care in putting
shaft through ceramic seat
to be sure it is not chipped.
Inspect seal after shaft is
in place. If seal has been
chipped it must be replaced.
Do not replace rotating part
of seal until the balance of
the pump is assembled.
7. Bearings. When the pump
rotor has been removed,
check bearings before
replacing. If bearings are
rusted or rough when turned,
they must be replaced. Pull
bearings with a bearing
puller. If puller cannot be
replaced over lower bearing,
remove the outer race by
cracking in a vise. After outer
race is cracked, it can be
removed and the balls can
be removed. This will allow
inner race to be pulled.
When replacing bearings
push only on inner race.
If a press is not available,
bearings can be tapped on,
using a sleeve that bears
only on the inner race.
Never pound on the outer
race or bearing will be
ruined.
8. Reassembly of stator and
housing. Replace stator (20)
with terminal block turned
toward switch pocket as
shown by drawing. Replace
plate and bolts (2). Be sure
ears on plate are in place
inside of shell of stator.
Replace cord (21) with push
on terminals in place on
terminal block. Bend tabs of
push on connectors down so
that they cannot touch plate
or housing. Place wire in
straight up position so that
housing (24) can be replaced
over wire. Be sure bearing
load springs are in place in
housing before replacing
housing. Hold springs in
place in housing with O-ring
lube, or other heavy grease.
Be sure rubber ring (3) is
in place on case when
lowering housing into
place. Tap down on top
of housing with plastic or
rubber hammer to seat over
bearing. Replace screws
(10) and tighten evenly from
one side to the other until
housing is firmly in place.
At this point turn shaft to be
sure rotor is free. If rotor
binds, it indicates screws
are not tightened evenly.

5
10.Oil fill. After air test is
satisfactory, remove from
water and wipe or blow off
any excess water.
Do not put oil in motor with
any water present that could
get into motor.
Fill to 1⁄8” over motor plate
through opening. Use oil fill
tube that will go into holes so
that air can escape. Replace
plug (12) and pump is ready
for operation. Use only high
grade transformer oil or
special Myers submersible
oil in motor.
11.Manual pumps. All general
instructions for automatic
pumps apply to manual
pumps except the level
switch is not used and the
power cord does not have a
vent tube.
Manual models have the
plug (12) in switch cap for
installing a fitting to air test
the pump for leaks. Replace
all plugs with Permatex on
threads. The switch housing
seat is tapped and plugged
with pipe plug.
MYERS pumps have a small
air vent hole in the impeller
cavity to let out trapped air.
If this hole becomes plugged,
pump may air lock. To break
the air lock, use a small
screwdriver to clear hole in
the impeller cavity.
As a secondary precaution
in installations of this type,
1⁄16” hole should be drilled
in the discharge pipe below
the check valve. The check
valve should be 12 to 18 inches
above pump discharge. Do not
put check valve directly into
pump discharge opening.
NOTE: In sumps where the
pump is operating daily, air
locking rarely occurs.
Push rubber seal ring (26)
around cord and replace
cord nut (25). Tighten cord
nut tight. Nut must be tight
enough so that cord cannot
be pulled up. Put cord into
switch cap and secure with
rubber ring and nut. Replace
switch as described earlier.
Now replace rotating part
of seal (8). Use tapered
installing sleeve furnished
with seal to push over shaft
threads. Screw impeller
(6) onto shaft. Hold shaft
with screwdriver in slot to
tighten on impeller. Replace
bottom casting (5).
Pump is now ready for
check run before air
testing and filling with oil.
Plug cord (21) into power
receptacle and push up on
switch chamber diaphragm
(23) to start motor. Motor
should start and run
smoothly. When pressure
is released on diaphragm,
motor should stop. Repeat
operation 2 to 3 times
to be sure operation is
satisfactory and not binding.
9. Air test. To air test unit, put
air fitting in plug opening
(12) and charge motor
housing with air to 7 psi.
Do not use higher pressure
or seal will be blown open.
Charge switch cap with air
through nylon vent tube as
described earlier and place
complete unit under water.
No air bubbles should show
on this test. If leak shows,
unit must be dismantled to
correct leak.
Pump
Servicing

6
MSP50
NOTE: Use Loctite on Impeller threads
MSP50
Parts List
13
1
21
3
20
2
12
5
11
15
17
16
19
18
8
7
9
14
410
6
Ref.
No. Object Description Qty Single Phase 115V Single Phase 230V 3 Phase
MSP50A1 10 MSP50A1 20 MSP50M1 10 MSP50M1 20 MSP50A2 10 MSP50A2 20 MSP50M7 20 MSP50M2 10 MSP50M2 20 MSP50M6 20 MSP50M3 20 MSP50M4 20 MSP50M5 20
1HOUSING-MOTOR CI PURCHASED COMPLETE 1.000 000560361 000562231
2NUT-CORD PLATED CRS 1.000 000750051
3O-RING .134 SQ 6.234 ID 1.000 000770031
4SEAL 5/8 SHAFT 1.000 14525A010
5SCREW-HHC 5/16-18UNC X 1-1/4 4.000 19100A012
6RING-SEAL .596 X .281 1.000 001390141
7SCREW CAP HEX 1/4 SST 5/8 LG 6.000 19099A029
8VOLUTE CASE CI 1.000 002020001
9PLATE-BOTTOM CI 1.000 002030002
10 IMPELLER CI 5-1/4 1.000 006140012
11 SWITCH BRACKET 1.000 055020051 055020051
12 OIL TRANSFORMER REFINED 0.54 GAL. 24709110000
13 PIPE PLUG 1/4" SCKT HD. W/SEALANT 1.000 149810011
14 NUT HEX SST 7/16-20 NF 1.000 19109A070
15 SCREW TAPPING SST #10 X 1/2LGINDENT WASH 1.000 09822A006 09822A006
16 FLANGE - 2" 1.000 002080001
17 SCREW CAP HEX SST 300 1/2-13UN 2.000 19103A052
18 GASKET-RUBBER 1/8 1.000 003240011
19 SWITCH-DIA 8.5" 115V 10' CORD 1.000 149740085-01 149740095-01
19 SWITCH-DIA 8.5" 230V 10' CORD 1.000 149740075-01 149740105-01
20 CORD-POWER 16-3 115V MLD TER & HARN 1.000 146230104 146230204 146230104 146230204
20 CORD-POWER 16-3 230V MLD TER & HARN 1.000 146232104 146232204 146234201 146232104 146232204
20 CORD-POWER ASSY 22' #16-4 SEW/EFF 1.000 116441895
21 MOTOR 1/2 HP 1.000 133490001 135920001 135940001 135950001 135960001
22 SCREW-MACH.(RD HD)1/4-28 X 1/2SST 18-8 1.000 001110081

7
16
4
17
8
21
7
13
9
12
14
19
18
22
20
1
11
2
15
53
6
10
MSP50AB1
Parts List
MSP50AB1
Ref. No. Object Description Quantity 28217D100
Component
1VOLUTE CASE BR 1.000 002020102
2PLATE-BOTTOM BR 1.000 002030102
3IMPELLER BR 5-1/4 FOR SP50 1.000 006140102
4 COVER-MOTOR 1.000 000560132
5SEAL 5/8 SHAFT -SEE 14525A000K B/CA/N/CE 1.000 14525A010
6 HANDLE-PUMP 1.000 000600005
7000750071 NUT - CORD BRZ 1.000 000750071
8O-RING .134 SQ 6.234 ID 1.000 000770031
9SCREW-HHC 5/16-18UNC X 1-1/4 4.000 19100A012
10 RING-SEAL .596 X .281 1.000 001390141
11 SCREW CAP HEX 1/4 SST 5/8 LG 6.000 19099A029
12 SWITCH BRACKET 1.000 055020051
13 OIL TRANSFORMER REFINED 0.38 GAL. 24709110000
14 SCREW TAPPING SST #10 X 1/2LGINDENT WASH 1.000 09822A006
15 NUT HEX SST 7/16-20 NF 1.000 19109A070
16 PLUG,PIPE;1/4-18NPT 1/4HEX SOCKET SST 31 1.000 05022A088
17 MOTOR 1/2 HP 115V 1.000 133490001
18 FLANGE-2" BR 1.000 002080102
19 SCREW CAP HEX SST 300 1/2-13UN 2.000 19103A052
20 GASKET-RUBBER 1/8 1.000 003240011
21 CORD-POWER 16-3 20' 115V MLD TER & HARN 1.000 146230204
22 SWITCH-DIA 8.5" 115V 20' CORD BR 1.000 149743095-01
NOTE: Use Loctite on Impeller threads

Limited Warranty
Myers®warrants to the original consumer purchaser (“Purchaser” or “You”) of the products listed below, that they will be free
from defects in material and workmanship for the Warranty Period shown below.
Product
Warranty Period
whichever occurs first:
Jet pumps, small centrifugal pumps, submersible pumps
and related accessories 12 months from date of original installation, or 18 months from date of manufacture
Fibrewound Tanks 5 years from date of original installation
Steel Pressure Tanks 5 years from date of original installation
Sump/Sewage/Effluent Products 12 months from date of original installation,
or 36 months from date of manufacture
Battery Backup Units
MBSP-2, MBSP-2C
MBSP-3, MBSP-3C
12 months from date of original installation,
or 18 months from date of manufacture
24 months from date of original installation,
or 30 months from date of manufacture
Wastewater Solids Handling Pumps 12 months from date of shipment from factory
or 18 months from date of manufacture
Our warranty applies only where such products are used in compliance with the requirements of the applicable product
catalog and/or manuals. For additional information, please refer to the applicable standard limited warranty featured in
the product manual.
Our warranty will not apply to any product that, in our sole judgement, has been subject to negligence, misapplication,
improper installation, or improper maintenance. Without limiting the foregoing, operating a three phase motor with single
phase power through a phase converter will void the warranty. Note also that three phase motors must be protected by
three-leg, ambient compensated, extra-quick trip overload relays of the recommended size or the warranty is void.
Your only remedy, and MYERS’s only duty, is that MYERS repair or replace defective products (at MYERS’s choice). You must
pay all labor and shipping charges associated with this warranty and must request warranty service through the installing
dealer as soon as a problem is discovered. No request for service will be accepted if received after the Warranty Period has
expired. This warranty is not transferable.
MYERS SHALL NOT BE LIABLE FOR ANY CONSEQUENTIAL, INCIDENTAL, OR CONTINGENT DAMAGES WHATSOEVER.
THE FOREGOING LIMITED WARRANTIES ARE EXCLUSIVE AND IN LIEU OF ALL OTHER EXPRESS AND IMPLIED WARRANTIES,
INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
THE FOREGOING LIMITED WARRANTIES SHALL NOT EXTEND BEYOND THE DURATION PROVIDED HEREIN.
Some states do not allow the exclusion or limitation of incidental or consequential damages or limitations on the duration of
an implied warranty, so the above limitations or exclusions may not apply to You. This warranty gives You specific legal rights
and You may also have other rights which vary from state to state.
This Limited Warranty is effective April 1, 2014 and replaces all undated warranties and warranties dated before April 1, 2014.
F.E. MYERS
293 Wright Street, Delavan, WI 53115
Phone: [phone] • Fax: [phone] • www.femyers.com
In Canada: 490 Pinebush Road, Unit 4, Cambridge, Ontario N1T 0A5
Phone: [phone] • Fax: [phone]