Franklin Electric MH Series User manual

MH Series Horizontal
Multi-stage Pump
Owner's Manual

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Before Getting Started
Read and follow safety instructions. Refer to product data plate(s) for additional operating
instructions and specications.
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RISK OF ELECTRIC SHOCK - This pump is supplied with a grounding conductor and grounding type
attachment plug. To reduce risk of electric shock, be certain that it is connected only to a properly
grounded, grounding-type receptacle. Disconnect power before working on or around the system. Do
not use in swimming areas.
This equipment should be installed by technically qualied personnel. Failure to install it in compliance
with national and local electrical codes and within Franklin Electric recommendations may result in
electrical shock or re hazard, unsatisfactory performance or equipment failure. Installation information
is available through pump manufacturers and distributors, or directly from Franklin Electric at our toll-
free number 1-800-348-2420.
This equipment must not be used by children or persons with reduced physical, sensory or mental
abilities, or lacking in experience and expertise, unless supervised or instructed. Children may not use
the equipment, nor may they play with the equipment or in the immediate vicinity.
If power cord suffers damages, consider this product does not allow partial replacement and therefore
should be fully replaced.
• Keep work area clean, well-lit, and uncluttered.
• Keep safety labels clean and in good condition.
• Wear safety glasses while installing or performing maintenance on pump.
• Do not run pump dry. Fill pump with water before starting or pump will be damaged.
• Make sure all ELECTRICAL POWER IS OFF before connecting any electrical wires. Follow all pump
wiring instructions provided in the "Wiring" section of this manual.
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This is the safety alert symbol. When you see this symbol on your pump or in this manual, look for
one of the following signal words and be alert to the potential for personal injury:
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DANGER
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NOTICE
warns about hazards that will cause serious personal injury, death or major
property damage if ignored.
warns about hazards that can cause serious personal injury, death or
major property damage if ignored.
warns about hazards that will or can cause minor personal injury or major
property damage if ignored.
indicates special instructions which are imported but not related to hazards.
Carefully read and follow all safety instructions in this manual and on pump.

Table of Contents
Before Getting Started ............................................................2
Introduction .....................................................................4
Electrical Installation ..............................................................7
Dual Voltage Adjustment...........................................................8
Operation .......................................................................9
Maintenance ....................................................................9
Service and Disassembly .........................................................10
Disassembly Instructions .........................................................10
Troubleshooting.................................................................11
Appendix 1 - HMS Performance Tables ..............................................12
Appendix 2 - Friction Loss Tables ..................................................13
Parts for Horizontal Multi-stage Pump...............................................14
Warranty.......................................................................15

4
MH Series Horizontal Multi-stage Pump
Introduction
The horizontal multi-stage centrifugal pump is well suited for the pumping of water in the housing,
agricultural, and industrial markets. This multi-purpose pump is designed for sprinkling/irrigation
systems, washing stations, draining/lling of ponds, etc., and water treatment systems. The all-
stainless-steel wet end of this pump features corrosion-resistant material, increasing the longevity
of the pump. This pump’s quiet operation makes it very suitable for home use. The different
models of the multi-stage centrifugal pump offer a wide range of varying ow rates and pressures.
There is one model for highest shut-off capability, one for highest ow capacity, and a standard
model for a good mix of both pressure and ow.
Features
Pump Casing/Shell 304 Stainless Steel
Hydraulics 304 Stainless Steel: corrosion-resistant, multi-stage from 2 to 6 stages
Mechanical Seal Carbon/Ceramic/Fluoroelastomer (FKM)
Electric Motor
Square ange, thermally protected, dual voltage, 115 V - 230 V, single or three-
phase, and hp ranging between 1/2 and 2, ensuring the proper motor is available to
meet a wide range of applications
Shaft 7/16" stainless steel hexagonal
Inspect Your Shipment
All pumps are carefully tested, inspected, and packaged to ensure their arrival in perfect condition.
When the pump is received, examine it closely to make sure there is no damage or broken parts
that may have occurred in shipping. If damage is evident, report this immediately to your shipping
carrier and dealer. The shipping carrier assumes full responsibility for the shipment’s safe arrival.
Any claim for damage to the shipment, either visible or concealed, must be made through the
shipping carrier rst.
Installation
Location of Pump
Decide on an area for the pump installation that is suitable based on the enclosure rating of the
electric pump motor.
Indoor Pump Installation Option
Choose a clean, well-ventilated, weatherproof location that affords protection from freezing,
ooding, and excessive heat. In addition, it should provide access for servicing and allow
convenient draining of the pump, tank, and service pipes. A prepared foundation is not essential,
provided the surface is hard and level. It can be located in the basement or utility room of your
house, at the well or between the house and the well. When installing outside of the house, the
pump should be protected by a pump house with auxiliary heat to prevent possible freezing.

MH Series Horizontal Multi-stage Pump
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Piping the Well
Suction tapping on the pump is 1-1/4" (1-1/2" for 45 gpm) (FNPT) in size. Suction pipe diameter
should never be smaller than the suction tapping.
A pump performs best when installed close to the well because suction lift and friction losses
are kept to a minimum. Although an installation near the water source is preferred, it may be
necessary or more convenient to locate the pump away from the well, lake or stream. FOR A
SHALLOW WELL INSTALLATION, the offset is limited only by the suction lift and the friction in
the plumbing system.
Plan your piping layout before starting the installation so that the correct pipe and ttings are
on hand to complete the job. Keep the pipes clean, since pebbles and other foreign material
can block the pump impeller and hinder operation. To avoid air pockets slope horizontal pipes
continuously upward from water source to pump by at least 1 vertical inch for every 30" of
horizontal run.
Horizontal Offset Suction Piping
When the pump is offset from the well, the horizontal offset suction piping may have to be
increased in diameter to reduce friction loss. The friction loss in a system increases:
1. As the ow rate increases;
2. As the piping size decreases.
Consult included performance tables (Appendix I) and friction loss tables (Appendix II) to
determine the amount of head lost for a given application. Pipes from the well to the pump should
slope upward (about 1" of rise for every 30" of run).
Discharge Pipe Sizes for Installation
When the pump is located at a distance from points of water use, it is necessary to increase the
discharge pipe size in order to reduce friction loss. The friction loss in a system increases:
1. As the ow rate increases;
2. As the piping size decreases.
Consult included performance tables (Appendix II) and friction loss tables (Appendix III) to
determine the amount of head lost for a given application.
Shallow Well Installation (Figure 1)
Connect pump to well as shown in Figure 1. Shallow well operation, suitable for depths not
exceeding 10 feet, requires only a single pipe to the water source. Typical water sources are
wells, lakes, ponds, streams or rivers. Support the suction pipe so its weight is not carried by the
pump. Installation should include a foot valve in the well or a check valve close to the pump. If the
distance from the well to the pump is more than 40 horizontal feet, a check valve (installed close to
the pump) is recommended in addition to the foot valve. The choice of using a check valve at the
pump or a submerged foot valve depends on the individual installation parameters. A foot valve is
required for a cased/dug well. Special care should be taken to ensure that all suction ttings are
tight and sealed. Otherwise, the pump cannot be primed or will lose prime over a period of time.

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MH Series Horizontal Multi-stage Pump
Discharge Plumbing
When using this pump in a shallow well application it is recommended to use an in-line pressure
switch and a properly sized pressure tank. This pump does not include a pressure switch and
these items must be purchased separately. Adding a gate valve in the discharge line can save the
need to drain the system when servicing the pump. Unions and other breakable pipe connections
close to the pump allow for easy accessibility when servicing. This set-up is typical and suitable for
shallow well pumping applications but not required for proper use.
Flooded Suction Booster Installation (Figure 2)
The horizontal multi-stage pump can be used in either an in-line or parallel boosting application.
Common installation for boosting municipal water pressure is using the parallel installation
(Figure 2). When using the pump in a boosting application, it is important to not exceed the
maximum operating pressure of the pump of 145 psi. Install a pressure relief valve on any boosting
application where the pump pressure can exceed the maximum working pressure of the plumbing,
tank or of the system.
1-1/4”Suction Pipe
Sanitary
Well Seal
Well
1-1/4”
Foot Valve
(1-1/2”for 45 gpm)
(1-1/2”for 45 gpm)
Figure 1 - Shallow Well Installation
Street Supply
Union
Valve (normally open)
Check Valve
Union
Horizontal Multistage Pump
Check Valve
Inlet
Union
Valve (normally open)
Flow
Flow
Flow
Pump used in boost incoming pressure
from city supply (Automatic Operation)
Outlet
Discharge
Flow
Pressure Tank
Pressure Gauge
Pressure Relief Valve
Drain Valve
Check Valve
Union
Pressure Switch
Figure 2 - Pump Installation Using Municipal Source

MH Series Horizontal Multi-stage Pump
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Installation Records
To keep an accurate record of your installation, be sure to ll out the data below:
Date of Installation: _____________________________
Model No: ____________________________________
Depth of water (ft): _____________________________
Suction pipe size: ______________________________
Pressure switch setting
ON (psi):__________ OFF (psi): ___________
Suction pipe length (ft.): _________________________
Discharge pipe length (ft.): _______________________
Voltage to motor: ______________________________
Discharge pipe size: ____________________________
Incoming Pressure (psi): _________________________
Electrical Installation
Hazardous voltage can shock, burn or cause death.
If you are not sure of proper electrical connections, consult a
licensed electrician.
Improper wiring can result in permanent damage to the motor.
All electrical wiring should meet the local electrical code.
READ AND FOLLOW ALL INSTRUCTIONS!
Pump connection must comply with National Electric Code (NEC) or Canadian Electric Code
(CEC), and all applicable local codes.
All dual voltage units come factory preset for 230 Volts (Figure 3).
Disconnect power at electrical panel before making any electrical connections.
Supply voltage must be +/- 10% of motor nameplate voltage. Low or high voltage can damage the
motor and will void the warranty.
If possible, connect pump to dedicated branch circuit with no other appliances on it.
Ground motor before connecting to power supply.
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MH Series Horizontal Multi-stage Pump
230V
115V
230V
115V
115 V 230 V
Figure 3
Dual Voltage Adjustment
NOTE: To change the motor voltage (Figure 3) unplug the dual voltage connector on the motor
and reconnect it in the position required to match the available electrical system. The motor can
be set for 115 Volts or 230 Volts. Voltage setting of the motor can be determined by looking at the
alignment of the arrow on the plug and the arrow on the motor terminal board (located under the
motor’s end cover). Any questions as to which voltage setting is required for proper motor and
pump operation in your system should be directed to an electrical professional. The factory preset
is 230 Volts.
Check motor terminal cover or nameplate for wiring instructions. The
essential pump motor facts are as follows:
1. 3450 rpm;
2. Single-phase;
3. Dual voltage, 115/230;
4. 1/2, 3/4, 1, 1-1/2, and 2 horsepower motors are wired for 230 Volts as a factory standard.
Note that all wiring is subject to ofcial inspection and must conform to the local electrical code.
Install a circuit breaker or fused disconnect switch near the pump. Connect the incoming power wires
to the LINE terminals and the green or bare wire to the ground screw, then ground the entire unit.
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NOTICE
Thermal Protection
W115/230 V
MH
HP W
1 ɸW 3ɸ
1/2 860 990
3/4 1140 1200
1 1360 1660
1.5 1740 2160
2 2200 2600

MH Series Horizontal Multi-stage Pump
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Operation
Priming (Figure 4)
The motor should not be started before pump is primed. To prime the pump, ll the pump case
and suction pipe completely with water. Install discharge and suction ttings securely to ensure
there are no system leaks. Use Priming Port.
Close all system outlets, then slightly crack one system outlet to allow for excess air to bleed
from the plumbing system. Start the pump. Water will start pumping in a few minutes; the time
is dependent on the distance to the water source. If after a few minutes of running you do not
get water, repeat priming process as all air was not discharged from the pump. Once the pump
is operating, open system outlets slowly and let pump operate until water runs clear. No further
priming should be necessary unless: the pump is drained for repair or storage, there is a leak in
the suction line plumbing, or there is a failure of the system’s foot or check valves.
NOTE: Three-phase units are designed to run in a counter-clockwise manner when viewed from
the pump end. Improper rotation can result in low performance or hydraulic failure.
MOTOR
Ensure motor is operating in a clean, dry environment.
Maintenance
Lubrication
The pump requires only water for lubrication and must never be run dry.
Running the pump dry may cause damage to the pump and system components.
Clean Water
Pump should not be primed until plumbed together
Pipe Plug
Priming Port
Figure 4 - Priming Shallow Well with Priming T
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MH Series Horizontal Multi-stage Pump
Draining
Before disconnecting pump, be sure fuse box leads are disconnected
or power is turned off. After reassembling the pump, refer to priming
instructions before running. If your pump must be drained for service or
to prevent damage from freezing, remove the drain plug from the pump case.
While this will drain the pump, it will not necessarily drain all other parts of the piping system. If
there are any concerns with the proper procedure or necessity of draining the suction plumbing,
contact your contractor.
All piping and water tanks exposed to freezing weather should be drained. If there are any concerns
with the proper procedure to drain the system's pressure tank, contact the tank manufacturer for
assistance.
Service and Disassembly
Before disconnecting pump, be sure fuse box leads are disconnected or power
is turned off at the breaker box. After reassembling the pump, refer to priming
instructions before running.
Disassembly Instructions
If you experience problems with your pump, determine the possible causes
from the service check list. (TROUBLESHOOTING) Follow the steps below to
disassemble the pump. Reassemble in reverse order. Clean the seals and the sealing surfaces in the
pump case. Lightly lubricate the rubber part of the seals with silicone grease to aid in assembly. DO
NOT lubricate the carbon or ceramic faces on the shaft seal.
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Drain Plug
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