Pentair MYERS MG200 Series Manual

NOTE! To the installer: Please make sure you provide this manual to the owner of the equipment or to the responsible
party who maintains the system.
MG200 SERIES
GRINDER PUMPS
INSTALLATION AND SERVICE MANUAL
2 HP Grinder Pump for Residential and Pressure Sewer Applications.
Part # 23833A664 | © 2014 Pentair Ltd. | 07/16/14

2
USAGE
The MG200 Series is a submersible wastewater
grinder pump designed specifically for individual
residential and pressure sewer applications. The
pumps are to be used for domestic sewage only
and are not to be used for pumping commercial or
industrial sewage such as from motels, schools,
apartments, factories, etc. THIS PUMP IS NOT FOR
USE IN HAZARDOUS LOCATIONS!
INSPECTING PUMP
Before making any piping or electrical connections,
check the pump for shipping damage or cracks.
Using a flat screwdriver placed in the slot on the
shaft end, turn shaft and impellers to be sure they are
free. DO NOT TURN IMPELLER WITH FINGERS AS
EDGES ARE SHARP.
POWER SUPPLY
The MG200 Series grinder pump should be connected
only to a 230 volt, single phase, 60 Hz power source.
The pump will draw approximately 9.1 amperes at
minimum flow and 15.0 full load amperes. The pump
must be connected to a grounded power socket. DO
NOT cut off the ground pin from the power cord plug.
POWER CORD
A 20 foot power cord is attached to the grinder pump
via three insulated quick-disconnect terminals. To
replace a cord simply unscrew (turn counterclockwise)
cord nut from top of motor housing. Once cord nut
is completely loosened from housing, gently pull
cord upward away from housing. While cord is being
pulled, it may be necessary to shift cord leads back
and forth to guide the insulated terminals through
the hole in the motor housing. Once the terminals
have cleared the hole, gently pull cord until terminals
are completely outside motor housing. Then simply
disconnect terminals to remove cord.
To install new cord, reconnect terminals (black to
black, white to white, green to green), and guide
terminals back through hole in motor housing. Once
terminals have passed through the hole, retighten the
cord nut into housing. Tighten nut firmly but do
not overtighten.
The power cord should be replaced if it has
been damaged in any way or the cord jacket
has become brittle.
MOTOR TYPE
The MG200 Series grinder pump contains a 3/4
frame, 2 HP, single phase, 60 Hz, 3450 RPM, capacitor
start, capacitor run motor with Class F insulation and
built-in, on-winding overload protection. Motor has
upper and lower ball bearings and is oil-cooled
and lubricated.
nCAUTION!
THE MG200 SERIES GRINDER PUMP SHOULD
NEVER BE WORKED ON WITHOUT FIRST
DISCONNECTING THE POWER CORD.
OIL TYPE
The motor housing contains dielectric transformer oil
to provide good heat transfer and lubrication of ball
bearings; no other lubrication is required. Oil level
may be checked by removing the nut and washers
from the top of the motor housing. The oil level
should be filled to the bottom of the end shield. Do
not overfill with oil. Only dielectric transformer oil
obtained from a Myers®authorized service center
should be used.
PUMP SWITCH INSTALLATION
INSTRUCTIONS
NOTE: In accordance with third party approval, pump
must be submerged a minimum of 8-1/2" from bottom
of the legs on volute case during operation.
Mounting the Switch
1. Determine pumping range for installation. Do not
tether less than 3-1/2" from pipe.
2. Tighten strap around discharge pipe keeping
switch cable between strap and pipe to prevent
slippage.
3. Space small ties at least 1" apart. To readjust ties,
press small tie tabs down.
4. To lock releasable tab, run remaining
strap between tab and head. Tuck strap back
through head.
Piggyback Plug Install
n Electrical outlet must not be located
in pump chamber.
n Electrical outlet voltage, piggyback plug voltage,
and pump voltage must match.
1. Follow steps 1 through 4 of “Mounting the Switch.”
2. Insert switch’s piggyback plug into outlet.
3. Plug pump into piggyback plug.
4. Check installation. Allow system to cycle to ensure
proper operation.
Direct Wire Install
1. Follow steps 1 through 4 of “Mounting the Switch.”
2. Further wiring of switch should be done by
qualified professionals only.
3. Check installation. Allow system to cycle to ensure
proper operation.

3
SAFETY WARNINGS
nWARNING! Risk of electrical shock. Pumps are
supplied with a grounding conductor and grounding-
type attachment plug on the power cord (except
MG200-21L/P). To reduce the risk of electrical
shock, be certain that it is connected only to properly
grounded, grounding-type receptacle. DO NOT cut
off ground pin or use an adapter fitting. DO NOT
use an extension cord with this pump. When wiring
this pump follow all local electrical, safety codes and
ordinances as well as most recent National Electric
Code (NEC-ANSI/NFPA).
The MG200 Series grinder pumps have a GROUND
WIRE that is connected to a screw in the metal motor
housing. This wire goes to the receptacle or control
box which must be connected to a good outside
GROUND such as a metal water pipe or GROUND
STAKE driven at least 8 feet into the ground.
CALIFORNIA PROPOSITION 65 WARNING:
This product and related
accessories contain chemicals known to the
State of California to cause cancer, birth
defects or other reproductive harm.
DISMANTLING PUMP FOR
REPLACEMENT PARTS
Before dismantling pump for replacement parts, clean
pump thoroughly.
REPLACING GRINDER IMPELLER AND
GRINDER SHREDDING RING
All repairs must be done at the factory or at an
authorized Myers®service facility.
nCAUTION!
DISCONNECT ALL POWER AND CONTROL
WIRES TO MOTOR AT CONTROL PANEL BEFORE
STARTING DISASSEMBLY OPERATIONS. NEVER
RELY ON OPENING CIRCUIT BREAKER ONLY.
DISASSEMBLY OF SHREDDING RING
AND GRINDER IMPELLER
1. Remove three screws from grinder ring flange.
Grinder ring is pressed into flange for easy
removal.
2. Using Allen head socket wrench, thread two
screws into tapped back-off holes in flange. Evenly
tighten screws to guide grinding ring out of pump
volute case.
3. Hold grinder impeller by prying against impeller
cutting bar and remove cap screw from end
of shaft.
4. Use large screwdriver in slot in end of shaft
and bump on cutter vane with plastic hammer.
Bump in counterclockwise direction as thread
is right-hand. It may take several bumps to
loosen impeller.
DO NOT CONTINUE TO POUND ON IMPELLER
AS IMPELLER AND SHAFT MAY BE DAMAGED.
5. If impeller comes off easily, clean and replace
if worn.
6. Be sure pump impeller has not loosened when
grinder impeller is removed. This can be checked
on reassembly of grinder impeller and shredding
ring. Tips of impeller cutter vanes should extend
about 1/8" below bottom of shredding ring. If
distance is more, it means the pump impeller has
loosened, and if it is less, it means the shredding
ring is not properly seated.
If the pump impeller has loosened, remove grinder
impeller and shredding ring as described above
and remove bolts from volute case and remove
case. Plastic hammer can be used to bump on
casing discharge to loosen. Place gasket in oil
to prevent drying out. DO NOT loosen the pump
impeller further – it is the seat for the seal spring.
7. After case is removed, wrap emery paper around
shaft and hold with vice grip pliers. Use cloth
on impeller and screw up against shoulder. Now
pump can be reassembled.
8. Clean all threads with wire brush and file; smooth
any threads that may have been nicked.
liquid-tight
connector
230V
pump
230V
power
source
junction
box
black
white
L1 L2
G
G
L1 L2
G
230 VAC
In 230 VAC pump installations, one side of
the line going to the pump is always HOT.
This condition exists if the switch is on or
off. Install double pole disconnect on all
230 VAC pump circuits.
n WARNING

4
9. Use Never Seez®or other graphite compound on
threads before replacing grinding impeller.
10.Be sure cap screw in bottom of shaft is tight. Hold
impeller with a screwdriver between cutter bar and
teeth of shredding ring while tightening cap screw.
11.Be sure impeller turns freely by hand after
reassembly. Some drag will occur due to the seal,
but there should be no binding or tight spots when
turning the grinder impeller.
12.If impeller rubs or drags on shredding ring, loosen
bolts in shredding ring plate and tap with plastic
hammer to loosen; retighten screws. Be sure to pull
screw down evenly, applying pressure on all three
screws. DO NOT TIGHTEN ONE SCREW CLEAR
DOWN BEFORE ADJUSTING OTHER SCREWS.
13.ALWAYS use a rag on the impeller when turning
to prevent cutting hands on the sharp corners of
shredding ring.
TO REPLACE CAPACITORS ONLY
1. Remove oil fill plug near the top of motor housing
and pour oil out.
2. Loosen the cord nut on power cord until
cord is loose enough to push cord down into
motor housing.
3. Remove four bolts from motor housing and bump
housing with a plastic hammer to loosen. Lay
pump on its side.
4. Remove the housing carefully to be sure that
enough cord is pushed into the housing so as not
to create tension on cord.
5. Slide motor housing up far enough to expose the
capacitors and to be able to lay the housing down.
6. Disconnect wiring from capacitor and loosen
capacitor clamp and slide capacitor out. Replace
with new capacitor, tighten clamp and reconnect.
7. Check all wiring connectors to be sure they
are secure.
8. Be sure tetraseal gasket is in place.
9. Slide motor housing back onto pump while pulling
the cord out slowly. Assemble motor housing with
four bolts.
10.Reassemble cord nut. Be sure washers are seated
and cord is pulled up against the washers. Tighten
nut securely.
11.Put pump upright and refill motor with Myers®
submersible pump oil. DO NOT OVERFILL
WITH OIL. Reassemble washer, gasket and nut
in motor housing. Retighten nut firmly, but do
not overtighten.
12.Be sure pump turns freely before connecting
power. Turn pump on side and turn impeller,
using screwdriver in slotted shaft. Plug pump
into receptacle to test operation. Pump must run
quietly and free of vibration.
WIRING DIAGRAM – AO SMITH®
RUN
CAPACITOR
START
CAPACITOR
20 μF
370 V 324 μF - 389 μF
125 V
BROWN BLACK
PHASE
MAIN
ORANGE
YELLOW
BLUE
RED
LINE
LINE
WHITE
PROTECTOR
SENSATA TECHNOLOGIES TYPE 15HM2412
2
3
5
1
4
6
WIRING DIAGRAM – MARATHON®
START
CAPACITOR
RUN
CAPACITOR

5
Pump does not run or hum.
See A, B, C, D, E or F.
Pump runs but does not
deliver water.
See G, H, I, J, K or L.
Pump runs and pumps out sump
but does not stop.
See M.
Pump runs but delivers only
small amount of water.
See I, J, K, L or N.
Fuse blows or circuit breaker
trips when pump starts.
See K, L, N, O or P.
Motor runs for short time
then stops. Then after
short period starts again.
Indicates tripping overload
caused by symptom shown.
See K, L, N or P.
For any other symptoms
contact a Myers authorized
service facility.
A. Line circuit breaker may be off;
or fuse, if used, may be blown
or loose.
B. Water level in sump may be too
low. Run in more water.
C. Pump cord plug may not be
making contact in receptacle.
D. If pump is using the series cord
plug, the two plugs may not be
plugged tightly together.
E. Float may be stuck. Be sure
float operates freely in basin.
Check tether length of switch.
F. If all symptoms check OK,
motor winding may be
open; take to service center
for repair.
G. Check valve may be installed
backward. Arrow on valve
points in direction of flow.
H. Discharge shut-off valve, if
used, may be closed.
I. Pump may be air locked. Start
and stop several times by
plugging and unplugging cord.
Check vent hole on pump case
for plugging.
J. Pump head may be too high.
Horizontal distance does
not affect pumping, except
loss due to friction.
K. Inlet holes in pump base may
be clogged. Remove pump
and clean out openings.
L. Impeller or volute openings may
be plugged or partially plugged.
Remove pump and clean.
Check tether length of switch.
M. Float is stuck in up position.
Be sure float operates freely
in basin.
N. Pump impeller may be
partially clogged causing
motor to run slow, resulting in
motor overload.
O. Fuse size or circuit breaker is
too small. Must be 20 amps.
P. Defective motor stator. Return
to Myers®service center.
TROUBLESHOOTING GUIDE

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5
4
7
8
9
10
11
12
13
14
15
16
17
18
19
20
6
13
1
2
3
MOTOR END PARTS
COMMON PARTS LIST
For use with product built with
Marathon®motor.
Ref. Part Number Description
1 26433D002 CASE, VOLUTE
2
21584B000 FLANGE, W/SHREDDING RING MG200
21584B003 FLANGE, W/SHREDDING RING MGH200
21584B004 FLANGE, W/SHREDDING RING MG200F
3 19099A012 SCREW, CAP 1/4" x 1" LONG., SST (3 REQ’D)
4 21583B000 RETAINER, IMPELLER, SST
5 07597A018 SCREW, FLAT HEAD, 1/4" x 3/4" LONG
6 25338B001 CORD, POWER
7 21582B000 IMPELLER, GRINDING
8 05013A039 SCREW, SET 1/4" x 3/8" LONG (2 REQ’D)
9
26434C010 IMPELLER, PUMP PLASTIC MG200
26434C000 IMPELLER, CAST IRON (OPTIONAL) MG200
22640C013 IMPELLER, DUCTILE IRON MGH200
26434C060 IMPELLER, PLASTIC MG200F
10 26430D001 PLATE, SEAL/BEARING
11 05014A181 GASKET, TETRASEAL 7" x 6-3/4" x 1/8"
12 25327D000 HOUSING, MOTOR
13 19100A012 SCREW, CAP, 5/16" x 1-1/4" LONG (8 REQ’D)
14 21576A010 SEAL, 7/8" SHAFT
15 26466C200 MOTOR, 230V, 1q, 2 hp
16 05022A092 PLUG, PIPE 1/4 NPT
17 05030A235 WASHER, SST, 3/32" THICK
18 05014A193 GASKET, RUBBER
19 05030A234 WASHER, SST, 1/32" THICK
20 25341A002 NUT, SOLID
– 145700041 RUN CAPACITOR
– 12141A000 START CAPACITOR

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1101 MYERS PARKWAY 490 PINEBUSH ROAD, UNIT #4
ASHLAND, OHIO, USA 44805 CAMBRIDGE, ONTARIO, CANADA N1T 0A5
419-289-1144 800-363-PUMP
WWW.FEMYERS.COM
Warranty Rev. 12/13
STANDARD LIMITED WARRANTY
Pentair Myers®warrants its products against defects in material and workmanship for a period of 12 months from the
date of shipment from Pentair Myers or 18 months from the manufacturing date, whichever occurs first – provided
that such products are used in compliance with the requirements of the Pentair Myers catalog and technical manuals
for use in pumping raw sewage, municipal wastewater or similar, abrasive-free, noncorrosive liquids.
During the warranty period and subject to the conditions set forth, Pentair Myers, at its discretion, will repair or
replace to the original user, the parts that prove defective in materials and workmanship. Pentair Myers reserves the
right to change or improve its products or any portions thereof without being obligated to provide such a change or
improvement for prior sold and/or shipped units.
Start-up reports and electrical schematics may be required to support warranty claims. Submit at the time of start-
up through the Pentair Myers website: http://forms.pentairliterature.com/startupform/startupform.asp?type=m.
Warranty is effective only if Pentair Myers authorized control panels are used. All seal fail and heat sensing devices
must be hooked up, functional and monitored or this warranty will be void. Pentair Myers will cover only the lower
seal and labor thereof for all dual seal pumps. Under no circumstance will Pentair Myers be responsible for the cost
of field labor, travel expenses, rented equipment, removal/reinstallation costs or freight expenses to and from the
factory or an authorized Pentair Myers service facility.
This limited warranty will not apply: (a) to defects or malfunctions resulting from failure to properly install, operate or
maintain the unit in accordance with the printed instructions provided; (b) to failures resulting from abuse, accident
or negligence; (c) to normal maintenance services and parts used in connection with such service; (d) to units that
are not installed in accordance with applicable local codes, ordinances and good trade practices; (e) if the unit is
moved from its original installation location; (f) if unit is used for purposes other than for what it is designed and
manufactured; (g) to any unit that has been repaired or altered by anyone other than Pentair Myers or an authorized
Pentair Myers service provider; (h) to any unit that has been repaired using non factory specified/OEM parts.
Warranty Exclusions: PENTAIR MYERS MAKES NO EXPRESS OR IMPLIED WARRANTIES THAT EXTEND BEYOND
THE DESCRIPTION ON THE FACE HEREOF. PENTAIR MYERS SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR ANY PARTICULAR PURPOSE.
Liability Limitation: IN NO EVENT SHALL PENTAIR MYERS BE LIABLE OR RESPONSIBLE FOR CONSEQUENTIAL,
INCIDENTAL OR SPECIAL DAMAGES RESULTING FROM OR RELATED IN ANY MANNER TO ANY PENTAIR MYERS
PRODUCT OR PARTS THEREOF. PERSONAL INJURY AND/OR PROPERTY DAMAGE MAY RESULT FROM IMPROPER
INSTALLATION. PENTAIR MYERS DISCLAIMS ALL LIABILITY, INCLUDING LIABILITY UNDER THIS WARRANTY, FOR
IMPROPER INSTALLATION. PENTAIR MYERS RECOMMENDS INSTALLATION BY PROFESSIONALS.
Some states do not permit some or all of the above warranty limitations or the exclusion or limitation of incidental or
consequential damages and therefore such limitations may not apply to you. No warranties or representations at any
time made by any representatives of Pentair Myers shall vary or expand the provision hereof.