Grundfos HS Series User manual

GRUNDFOS INSTRUCTIONS
HS
Horizontal, single-stage end suction pumps
Installation and operating instructions
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CONTENTS
1. Shipping inspection 2
2. Applications and operating ranges 2
3. Installation 2
4. Startup 5
5. Operation and Maintenance 6
6. Parts lists and Diagrams 8
7. Troubleshooting 10
SAFETY WARNING
Electrical Work
All electrical work should be performed by a
qualified electrician in accordance with the
latest edition of the National Electrical Code,
local codes and regulations.
Shock Hazard
A faulty motor or wiring can cause electrical shock that
could be fatal, whether touched directly or conducted
through standing water. For this reason, proper grounding
of the pump to the power supply’s grounding terminal is
required for safe installation and operation.
In all installations, the above-ground metal plumbing
should be connected to the power supply ground as
described in Article 250-80 of the National Electrical Code.
PLEASE KEEP THESE INSTRUCTIONS WITH THE PUMP FOR
FUTURE REFERENCE.
Preinstallation checklist
Your Grundfos HS End Suction pump is of the utmost
quality. Combined with proper installation, your Grundfos
pump will give you many years of reliable service.
To ensure the proper installation of the pump, carefully
read the complete manual before attempting to install the
pump.
Check the condition of the pump
Examine your pump carefully to make sure that no damage
has occurred during shipment.
Your Grundfos HS pump should remain in its shipping
carton until it is ready to be installed. This carton has been
specially designed to protect the pump from damage.
During unpacking and prior to installation, care should be
taken to ensure the pump is not dropped or mishandled.
Immediately report any damage in writing to the trans-
portation company and ask to have it inspected. Do not
destroy packing materials until the shipment is inspected
and the claim is settled.
The position of the coupling (that connects the pump
shaft to the motor shaft) is set at factory specifications.
No adjustment is necessary or advised. Refer to “Motor
Replacement” on page 6 for proper coupling positioning
procedures.
Applications and operating ranges
Before installing the pump, the following checks should be
made to ensure that the proper operating conditions for the
pump are present.
Applications
The HS end suction pump is a general service pump
designed to pump fluids in a wide range of applications.
Acceptable fluids include:
• Hot and cold water
• Clean, thin, non-aggressive and non-explosive fluids
• Consult manufacturer for fluids containing chlorine or
hydrocarbons
Operating Ranges
• Maximum fluid temperature: 180°F continuous
211°F intermittent
• Maximum working pressure: 125 PSIG
• Maximum ambient temperature: 104°F (40°C)
Consult manufacturer for higher ambient temperature
conditions.
Installation
Pump location
The pump should be located in a dry, well-ventilated area
which is not subject to freezing or extreme variations in
temperature. Care must be taken to ensure that the pump
is mounted at least 6 inches from any obstruction or hot
surfaces. The motor requires an adequate air supply to
prevent overheating and adequate space to remove the
motor for repair.
For open systems requiring suction lift, the pump should be
located as close to the water source as possible to reduce
piping losses.
Foundation
Concrete or similar foundation material should be used
to provide a secure, stable mounting base for the pump
in order to minimize noise and vibration in the system. It
is not recommended to hang the pump unit in the system
piping without added support. Bolt hole center line dimen-
sions for the various pump types are given in Figure 1 on
page 3. Secure the pump to the foundation using all four
bolt holes. Uneven surfaces can result in pump base break-
age when the mounting bolts are tightened.

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HS 100, HS 125, and HS 150 HS 150
(2 and 3 hp) (5 and 7 1/2 ph)
FIGURE 1: Bolt hole centers
Pipework
The use of pipe compound or teflon tape on all male threads
is acceptable as a means of providing a positive seal at the
pump port conditions. Avoid using unnecessary fittings,
valves or accessory items, especially in the vicinity of the
pump suction and discharge ports. The piping should be
adequately supported to reduce thermal and mechanical
stresses on the pump.
Good installation practice recommends the system be
thoroughly cleaned and flushed of all foreign materials and
sediment prior to pump installation. If possible, the pump
should not be installed at the lowest point in the system
due to the natural accumulation of dirt and sediment. If
there is excessive sediment or suspended particles present,
it is advised a strainer or filter be used to prevent its entry
into the pump.
Suction pipe
The suction pipe should be adequately sized and run as
straight and short as possible to keep friction losses to a
minimum. This would generally dictate that the suction
piping, fittings, valves and accessories be at least as large
as the suction port connection of the pump. These should
be larger if the distance to the water source is great.
Care should be taken to provide a means of pump isolation
(e.g., gate or butterfly valves) in applications where the
pump is in a pressurized or flooded suction condition.
If the pump is installed in a suction lift application, hori-
zontal suction piping must rise gradually from the source
to the pump and contain no high spots which allow air
pockets to form.
Discharge piping
It is suggested that a check valve and isolation valve be
installed in the discharge pipe. Pipe, valves, and fittings
should be at least the same diameter as the discharge pipe
or sized in accordance with good piping practices to reduce
fluid velocities and pipe friction losses. Pipe, valves and
fittings must have a pressure rating equal to or greater
than the maximum system pressure. Before the pump is
installed, it is recommended that the discharge piping be
pressure checked to at least the maximum pressure the
pump is capable of generating or as required by codes or
local regulations.
The standard discharge position for Grundfos Series
HS pumps is vertical (upward). To simplify pumping
connections, however, the pump volute may be rotated to
optional positions. The HS 100, HS 125, and HS 150 (2 HP
and 3 HP) models may be rotated to any of four positions
while the HS 150 (5 HP and 7 HP) may be rotated to any of
six positions. (See Figure 2).
HS 100, HS 125 HS 150
HS 150 (2 hp and 3 hp) (5 hp and 7 1/2 hp)
(4) discharge positions (6) discharge positions
FIGURE 2: Piping connection positions
(viewed from suction end)
Reposition the pump volute as follows:
1. Loosen and remove each of the cap screws that attach
the pump volute to the motor stool.
2. Carefully lift the pump volute off of the motor stool
and rotate it to the required position. Check that the
o-ring is properly seated.
3. Apply teflon sealant to the cap screw threads.
4. Reinstall the cap screws and tighten diagonally and
evenly.
Bypass
A bypass or pressure relief valve should be installed in the
discharge pipe if there is any possibility that the pump may
operate against a closed valve in the discharge line. Flow
through the pump is required to ensure that adequate cool-
ing and lubrication of the pump is maintained. See Table A
on page 4 for minimum flow rates.

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TABLE A: Minimum Pumping Rates
Pump Minimum
Type Flow Rates
HS 100 (all) 3 U.S. GPM
HS 125 (all) 4 U.S. GPM
HS 150 2020 8 U.S. GPM
HS 150 3030 10 U.S. GPM
HS 150 5050 12 U.S. GPM
HS 150 7575 13 U.S. GPM
Electrical
All electrical work should be performed by a
qualified electrician in accordance with the
latest edition of the National Electric Code and
local codes and regulations.
WARNING: The safe operation of this
pump requires that it be grounded in accord-
ance with the National Electric Code and local
governing codes or regulations. Connect the
ground wire to the grounding screw in the ter-
minal compartment and then to the acceptable
grounding point.
Motor
Grundfos HS pumps are supplied with heavy-duty 2-pole
3450 RPM, ODP or TEFC NEMA C frame motors selected
to our rigid specifications. Motors have been selected to
operate without exceeding their service factor ratings.
Motors with other enclosure types and for other voltages
and frequencies are available on a special order basis. If you
are replacing the pumping unit, but using a motor supplied
separately, be sure to read the “Motor Replacement”
instructions on page 6 for proper adjustment of the pump
shaft.
Motor mounting position
Motors up to 3 HP can be mounted in any of four positions
in 90° steps. To rotate the motor:
1. Remove the four cap screws securing the motor to the
pump.
2. Turn the motor to the desired position.
3. Replace the motor and securely tighten the four bolts.
Note: ODP motors through 3 HP are supplied with cooling
vents. These motors should remain mounted with the
cooling vents positioned downward, especially where there
is the possibility that liquid might splash onto the pump
from above (i.e., rain).
FIGURE 3: Motor mounting positions
Supply power
Verification of the electrical supply should be made to be
certain the voltage, phase, and frequency match that of the
pump motor. The proper operating voltage and other elec-
trical information can be found on the motor nameplate.
These motors are designed to run on + or - 10% of the
nameplate rated voltage.
Wiring connection diagrams can be found on the plates
attached to the motor.
WARNING: If voltage variations are larger than + or - 10%,
DO NOT operate the pump.
Field wiring
Wire sizes should be based on the current carrying proper-
ties of a conductor as recommended by the latest edition of
the National Electric Code or local regulations.
Direct on line (D.O.L.) starting is approved due to the
extremely fast run-up time of the motor and the low
moment of inertia of the pump and motor. If D.O.L.
starting is not acceptable and reduced starting current
is required, an auto transformer, resistant starter, or soft
start should be used.
It is recommended that a fused disconnect be used for each
pump where service and standby pumps are installed.
Motor protection
SINGLE-PHASE MOTORS
Single phase Series HS pumps are equipped with multi-
voltage, squirrel cage induction motors with built-in ther-
mal protection.
THREE-PHASE MOTORS
HS pumps with three-phase motors must be used with
the proper size and type of motor starter to ensure that
the motor is protected against damage from low voltage,
phase failure, current imbalance, and overloads. A properly
sized starter with manual reset and ambient-compensated
extra quick trip in all three legs should be used.

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The overload should be sized and adjusted to the current
rating of the motor.
Under no circumstances should the overloads
be set to a higher value than the service factor
current shown on the motor nameplate. This
will void the warranty.
Overloads for auto transformers and resistant starters
should be sized in accordance with the recommendations
of the manufacturer.
Pump Startup
Priming the pump and venting the system
After the pump has been installed, wired and the system
filled, the following procedures should be performed.
CAUTION: Do not start the pump before priming
and venting the pump. Never operate the pump
dry.
To prime the pump in a closed system or an open system
where the water source is above the pump, close the pump
isolation valve(s) and remove the topmost drain/vent plug
from the front of the pump volute. Gradually open the
isolation valve in the suction line until a steady stream
of airless water runs out of the open plug. Replace the
plug and securely tighten. Completely open the isolation
valves.
FIGURE 4: Priming the pump and venting the system
In open systems where the water level is below the pump
inlet, the suction pipe and pump must be filled and
vented of all air before starting the pump. This is best
accomplished through the discharge port or an opening
in the discharge piping at a level above the pump volute.
Remove the topmost drain/vent plug. Pour water into the
discharge until the suction piping and pump are completely
filled. If the suction piping does not slope downward from
the pump toward the water level, the air in the line must
be purged while the system is being filled. Replace the
drain/vent plug and securely tighten. Connect and/or seal
the discharge piping.
Check motor rotation
1. Make sure power is off.
2. Check to make sure the pump has been filled and
vented.
3. Rotate the pump shaft to be certain it turns freely.
4. Verify that the electrical connections are in accordance
with the wiring diagram on the motor.
5. Briefly switch the power on and observe the direction
of rotation. When viewed from the motor end, the
pump should rotate CLOCKWISE. (NOTE: Direction of
rotation on HS pumps is opposite that of CR, LM/LP and
VersaFlo TP pumps).
6. To reverse the direction of rotation, first switch off the
supply power.
7. On the three-phase motors, interchange any two power
leads on the load side of the starter. On single-phase
motors, see the connection diagram on the motor and
change the wiring as required.
8. Repeat step 3 to ensure that improper rotation has not
unthreaded the impeller from the pump shaft.
9. Switch on the power and again check the motor for
proper rotation.
Starting and adjusting
Before starting the pump, be sure to check:
1. Pump is primed.
2. Direction of rotation is COUNTERCLOCKWISE when
viewed from the suction port.
3. All piping connections are tight and pipes are ade-
quately supported.
4. Suction line isolation valve is completely open (if valve
is installed).
5. For initial starting, the isolation valve in the discharge
pipe should be closed and gradually opened after the
pump is turned on. Opening this valve too fast may
cause water hammering in the discharge pipe. Unless
the discharge valve is being used as a flow throttling
device, make sure the valve is completely open.
6. Check and record the voltage and amperage of the
motor. Adjust the motor overloads if required.
7. Check and record operating pressures, if pressure
gauges have been installed.

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8. Check all controls for proper operation. If the pump
is controlled by a pressure switch, check and adjust
the cut-in and cut-out pressures. If low-water-level
controls are used, be sure the low-water-level switch is
properly adjusted so the pump cannot run if the pump
should break suction.
Operation and maintenance
Operation
When Grundfos HS centrifugal pumps are installed in
accordance with these instructions and sized for correct
performance, they will operate efficiently and provide
years of service. The pumps are water lubricated and do not
require any external lubrication or inspection. The motors
may require periodic lubrication as noted in the following
maintenance information.
Under no circumstances should the pump be operated for
any prolonged periods of time without flow through the
pump.
This can result in motor and pump damage due to over-
heating. A properly sized relief valve or bypass line should
be installed to allow sufficient water to circulate through
the pump to provide adequate cooling and lubrication of
the pump bearings and seals.
Pump cycling should be checked to ensure the pump is not
starting more than 20 times per hour on  HP to 5 HP mod-
els or 15 times per hour on 7  HP models. Rapid cycling is
a major cause of premature motor failure due to increased
heat build-up in the motor. If necessary, adjust controls to
reduce the frequency of starts and stops.
Freeze protection
If the pump is installed in an area where freezing could
occur, the pump and system should be drained during
freezing temperatures to avoid damage. To drain the pump,
close the isolation valves and remove the drain/vent plugs
at both the top and bottom of the pump volute. DO NOT
replace the plugs until the pump is to be used again.
Maintenance
Motor lubrication
Electric motors are pre-lubricated at the factory and do not
require additional lubrication at start-up. Motors without
external grease fittings have sealed bearings that cannot
be re-lubricated. Motors with grease fittings should only
be lubricated with approved types of grease. Do not over-
grease the bearings. Over greasing will cause increased
bearing heat and can result in bearing/motor failure. Do
not mix petroleum grease and silicon grease in motor bear-
ings.
Bearing grease will lose its lubricating ability over time,
not suddenly. The lubricating ability of a grease (over
time) depends primarily on the type of grease, the size of
the bearings, the speed at which the bearings operate and
the severity of the operating conditions. Good results can
be obtained if the following recommendations are used in
your maintenance program.
Severity Ambient Environment Approved
of Temperature Types
Service (Maximum) of Grease
Standard +104°F (+40°C) Clean, little corrosion
Severe +122°F (+50°C) Moderate dirt, corrosion
Extreme >+122°F (+50°C) Severe dirt, abrasive
or Class H insulation dust, corrosion
Motor lubrication schedule
NEMA Frame Size 56 to 210
Severity Interval Weight of Volume of
of (Hours) Grease to Add Grease to Add
Service (oz) (in3/tspn)
Standard 5500
Severe 2750 0.3 0.6/2
Extreme 550
Preventative maintenance
At regular intervals, depending on the conditions and time
of operation, the following checks should be made:
1. Pump meets required performance and is operating
smoothly and quietly.
2. There are no leaks, particularly at the shaft seal.
3. The motor is not overheating.
4. Remove and clean all strainers or filters in the system.
5. Verify the tripping of the motor overload protection.
6. Check the operation of all controls. Check until control
cycling twice and adjust if necessary.
7. If the pump is not operated for unusually long periods,
the unit should be maintained in accordance with
these instructions. In addition, if the pump is not
drained, the pump shaft should be manually rotated or
run for short periods of time at monthly intervals.
If the pump fails to operate or there is a loss of perform-
ance, refer to pages 11 - 13, “Troubleshooting.”
Motor replacement
If the motor is damaged as a result of bearing failure,
burning, or electrical failure, the following instructions
detail how to remove the motor for replacement. It must be
emphasized that motors used on HS pumps are specifically
selected to our rigid specifications. Replacement motors
must be of the same NEMA C frame size and have the same
service factor.
Failure to follow these recommendations may result in
premature motor failure.
See motor
nameplate for
grease type or
compatible
equivalent type
of grease

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Disassembly
1. Using the proper allen wrench, loosen the set screw(s)
in the coupling.
2. With the correct size wrench, loosen and remove the
four bolts which hold the motor to the discharge sec-
tion of the pump end motor support.
3. Move the motor straight back until the shaft is free
from the coupling.
Assembly
1. If not already done, disconnect the motor stool
from the pump volute by removing the cap screws
which join the two together. Carefully pull the motor
stool and rotating assembly out of the pump volute.
2. Thoroughly clean the surfaces of the motor and pump
end mounting flanges.
3. Place the stub shaft onto the end of the motor shaft.
Connect the motor and motor stool by inserting the
mounting bolts and tightening them diagonally and
evenly (torque 15 to 20 ft. lbs.).
4. Using the appropriate edge of impeller spacing tool
SV00201 (see Table C), position the impeller at the cor-
rect axial location and tighten allen shaft set screw(s)
into the motor shaft’s keyway (see Figures 5A, B & C).
5. Attach the motor stool to the pump volute with the
cap screws, ensuring that the terminal box or conduit
connection and the pump’s discharge port are correctly
oriented for your installation. Replace the attaching cap
screws and torque to 25 ft. lbs.
6. Be certain the pump shaft can be rotated by hand. If
shaft cannot be rotated or it binds, repeat steps 4 and 5.
FIGURE 5A: Pump assembly (HS 100 and HS 125)
FIGURE 5B: Pump assembly (HS 150 2020 and 3030)
FIGURE 5C: Pump assembly (HS 150 5050 and 7575)
TABLE C: Impeller - Motor Support Positioning
Pump Impeller Distance to
Model(s) Motor Support
HS 100 (all) 1/32”*
HS 125 (all) 1/32”*
HS 150 (2020 & 3030) 1/4”*
HS 150 (5050 & 7575) 1/4”*
* Use Spacing Tool SV00201 included in seal kits and
repair kits (thin edge = 1/32”, thicker edge = 1/4”)
Spacing Tool SV00201

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TABLE D: Repair Kits
Shaft Seal & Gasket Kits
HS 100 & 125 (Buna-N) Part No. 47U08900
HS 100 & 125 (FKM) Part No. 47U08901
HS 150 (Buna-N) Part No. 47U08903
HS 150 (FKM) Part No. 47U08904
Repair Kits
HS 100 & 125 (Buna-N) Part No. 47U08906
HS 100 & 125 (FKM)* Part No. 47U08907
HS 150 2020 & 3030 (Buna-N) Part No. 47U08909
HS 150 2020 & 3030 (FKM)* Part No. 47U08910
HS 150 5050 & 7575 (Buna-N) Part No. 47U08912
HS 150 5050 & 7575 (FKM)* Part No. 47U08913
*Includes 416ss Stub Shaft
Repair Kits consist of the shaft seal and gasket kit, stub
shaft, and hardware. Impellers must be ordered sepa-
rately.
REFER TO THE KITS AND SPARE PARTS PRICE LISTS FOR A
COMPLETE LISTING OF KIT COMPONENTS
Part Lists and Diagrams (Model B)
HS 100 0505 to HS 125 1515
HS100 - 0305 to HS125 - 1520
Motor Stool, 56C Frame
Pump Base
3/4” Type 21 John Crane Seal
Stub Shaft
Impeller - HS 100 0505
Impeller - HS 100 0707
Impeller - HS 125 1010
Impeller - HS 125 1515
Pump Volute - HS 100
Pump Volute - HS 125
Steal Ring
Volute Gasket
Shaft Set Screw
3/8-16 x 3/4” Cap Screws
5/16-18 x 3/4” Cap Screws
1/2-13 x 11/4” Cap Screw
1/4” NPT Pipe Plug
(for discharge tap)
1/8” Pipe Plugs
Washer
Cap Screw
Pos.No. Description
1
2
3
4
5
6
7
8
9
11
12
14
15
16
18
20
1
1
1
1
1
1
1
1
1
4
4
1
1
4
1
1
47U09000
47U09006
See Kits
Brass-47U09013
416ss-47U09014
47U09020
47U09025
47U09030
47U09035
47U09065
47U09066
47U09075
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
# Used Part No. *

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Part Lists and Diagrams (Model B)
HS 150 5050 & HS 150 7575
Motor Stool, 56C Frame
Pump Base
1” Type 21 John Crane Seal
Stub Shaft, 416ss
Impeller - HS 150 2020
Impeller - HS 150 3030
Pump Volute
Volute Gasket
5/16-18 x 3/8” Shaft Set Screw
Woodruff Key
3/8-16 x 3/4” Cap Screws
5/16-18 x 3/4” Cap Screws
1/2-13 x 11/4” Cap Screw
1/4” Pipe Plug
1/8” Pipe Plugs
Impeller Washer
Impeller Lock Nut
Pos.No. Description
1
2
3
4
5
6
8
9
10
11
12
14
15
16
17
19
1
1
1
1
1
1
1
1
1
4
4
1
1
4
1
1
47U09002
47U09006
See Kits
47U09016
47U09045
47U09050
47U09067
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
# Used Part No. *
Part Lists and Diagrams (Model B)
HS 150 2020 to HS 150 3030
Motor Stool, 182TC/184TC
1” Type 21 John Crane Seal
Stub Shaft, 416ss
Impeller - HS 150 5050
Impeller - HS 150 7575
Pump Volute
Volute Gasket
5/16-18 x 3/8” Shaft Set Screw
Woodruff Key
1/2-13 x 3/4” Cap Screws
5/16-18 x 1” Cap Screws
1/4” Pipe Plug
1/8” Pipe Plugs
Impeller Washer
Washer
5/16-18 x 3/4” Cap Screw
Pos.No. Description
1
3
4
5
6
8
9
10
11
12
15
16
17
18
20
1
1
1
1
1
1
2
1
4
6
1
4
1
1
1
47U09004
See Kits
47U09018
47U09055
47U09060
47U09068
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
See Kits
# Used Part No. *
* Part numbers listed indicate the part is available
separately. If “See Kits” appears after the part name,
the part is only available in a kit.
Stub Shaft - HS 100 & 125 1
Stub Shaft - HS 100 & 125 1
Stub Shaft - HS 150 2020 & 3030 1
Stub Shaft - HS 150 5050 & 7575 1
Pos. No. Description
4Brass-47U09011
416ss-47U09012
416ss-47U09015
416ss-47U09017
# Used Part No. *
Part Lists and Diagrams (Model A)

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How to measure
Use a volt meter (set to proper scale) to
measure the voltage at the pump termi-
nal box or starter.
On single-phase units, measure between
power leads L1 and L2 (or L1 and N for 115
volt units). On three-phase units, meas-
ure between:
• Power leads L1 and L2
• Power leads L2 and L3
• Power leads L3 and L1
What it means
When the motor is under load, the
voltage should be within ± 10% of the
nameplate voltage. Larger voltage vari-
ation may cause winding damage.
Large variations in the voltage indicate
a poor electrical supply and the pump
should not be operated until these vari-
ations have been corrected.
If the voltage constantly remains high or
low, the motor should be changed to the
correct supply voltage.
Supply voltage
How to measure
Use an ammeter (set on the proper
scale) to measure the current on each
power lead at the terminal box or
starter. See the motor nameplate for
amp draw information.
Current should be measured when the
pump is operating at constant discharge
pressure.
What it means
If the amp draw exceeds the listed serv-
ice factor amps (SFA) or if the current
imbalance is greater than 5% between
each leg on three-phase units, check the
following:
1. Burned contacts on the motor starter.
2. Loose terminals in starter or terminal
box or possible wire defect.
3. Too high or too low supply voltage.
4. Motor windings are shorted or
grounded. Check winding and insula-
tion resistances.
5. Pump is damaged causing a motor
overload.
Current measurement
How to measure
Turn off power and disconnect the
supply power leads in the pump
terminal box. Using an ohm or mega
ohm meter, set the scale selector to
R x 100K and zero adjust the meter.
Measure and record the resistance
between each of the terminals and
ground.
What it means
Motors of all HP, voltage, phase and
cycle duties have the same value of
insulation resistance. Resistance values
for new motors must exceed 1,000,000
ohms. If they do not, the motor should
be repaired or replaced.
Insulation resistance
Troubleshooting
WHEN WORKING WITH ELECTRICAL CIRCUITS, USE CAUTION
TO AVOID ELECTRICAL SHOCK. It is recommended that rub-
ber gloves and boots be worn, and metal terminal boxes
and motors be properly grounded before any work is done.
WARNING: Failure to ground the pump may result in
serious electrical shock.
Preliminary tests

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Possible causes
1. No power at motor.
2. Fuses are blown or circuit
breakers are tripped.
3. Motor starter overloads
are burned or have tripped
out.
4. Starter does not energize.
5. Defective controls.
6. Motor is defective.
7. Defective capacitor (single-
phase motors)
8. Pump is bound.
1. Wrong rotation.
2. Pump is not primed or is air
bound.
3. Strainer, check valve, or
foot valve is clogged.
4. Suction lift is too large.
5. Suction and/or discharge
piping leaks.
6. Pump is worn.
7. Pump impeller or connec-
tion port is clogged.
How to check
Check for voltage at motor
terminal box.
Turn off power and remove
fuses. Check for continuity
with ohm meter.
Check for voltage on line and
load side of starter.
Energize control circuit and
check for voltage at the hold-
ing coil.
Check all safety and pressure
switches for operation. Inspect
contact in control devices.
Turn off power and disconnect
wiring. Measure the lead to
lead resistances with the ohm
meter (R x 1). Measure lead to
ground values with ohm meter
(R x 100K). Record measured
values.
Turn off power and discharge
capacitor. Check with ohm
meter (R x 100K).
Turn off power and manually
rotate pump shaft.
Check wiring for proper con-
nections.
Turn pump off, close isolation
valve(s), and remove the prim-
ing plug. Check fluid level.
Remove strainer, screen or
valve and inspect.
Install compound pressure
gauge at the suction side of
the pump. Start pump and
compare reading to perform-
ance data.
Pump runs backwards when
turned off. Air in suction pipe.
Install pressure gauge, start
pump, gradually close the dis-
charge valve and read pressure
at shut-off.
Disassemble and inspect pump
passageways.
Fault
A. Pump does not run.
B. Pump runs but at reduced
capacity or does not deliver
water.
Troubleshooting Chart
How to fix
If no voltage at motor, check
feeder panel for tripped cir-
cuits and reset circuit.
Replace blown fuses or reset
circuit breaker. If new fuses
blow or circuit breaker trips,
the electical installation,
motor, and wires must be
checked.
Replace burned heaters or
reset. Inspect starter for other
damage. If heater trips again,
check the supply voltage and
starter holding coil.
If no voltage, check control
circuit fuses. If voltage, check
holding coil for shorts. Replace
bad coil.
Replace worn or defective parts
or controls.
If an open or grounded wind-
ing is found, remove the motor
and repair or replace.
When the meter is connected
to the capacitor, the needle
should jump towards “0”
ohms and slowly drift back to
infinity. Replace capacitor if
defective.
If shaft does not rotate eas-
ily, check coupling setting and
adjust as necessary. If shaft
rotation is still tight, remove
pump and inspect. Disassem-
ble and repair.
Correct wiring.
Refill the pump, replace the
plug, and start the pump. Long
suction lines must be filled
before starting the pump.
Clean and replace. Reprime
the pump.
Reduce suction lift by lowering
the pump, increasing the suc-
tion line size, or removing high
friction loss devices.
Suction pipe, valves, and fit-
tings must be airtight. Repair
any leaks and retighten all
loose fittings.
Convert PSI to feet (Measured
PSI x 2.31 ft. / PSI = ____ft.)
Refer to the specific pump
curve for shut-off head for that
pump model. If head is close
to curve, pump is probably
OK. If not, remove pump and
inspect.
Remove any foreign materials
found.

English (US)
12
chapter discard.fm Page 12 Tuesday, June 7, 2011 9:29 PM
Possible causes
1. Pressure switch is not prop-
erly adjusted or is defective.
2. Level control is not properly
set or is defective.
3. Insufficient air charging or
leaking tank or piping.
4. Tank is too small.
5. Pump is oversized.
1. Low voltage.
2. Starter overloads are set
too low.
3. Three phase current is
imbalanced.
4. Motor is shorted or
grounded.
5. Wiring or connections are
faulty.
6. Pump is bound.
7. Defective capacitor (single-
phase motors).
8. Motor overloads at higher
ambient temperature than
motor.
How to check
Check pressure setting on
switch and operation. Check
voltage across closed contacts.
Check setting and operation.
Pump air into tank or dia-
phragm chamber. Check dia-
phragm for leak. Check tank
and piping for leaks with soap
and water solution. Check air
to water volume.
Check tank size and air volume
in tank. Tank volume should
be approximately 10 gallons
for each gpm of pump capac-
ity. The normal air volume is
2/3 of the total tank volume at
the pump cut-in pressure.
Install pressure gauges on or
near pump suction and dis-
charge ports. Start and run
pump under normal condi-
tions, record gauge readings.
Check voltage at starter panel
and motor.
Cycle pump and measure
amperage.
Check current draw on each
lead to the motor.
Turn off power and dissconnect
wiring. Measure the lead-to-
lead resistance with an ohm
meter (R x 1). Measure lead-
to-ground values with an ohm
meter (R x 100K) or a mega-
ohm meter. Record values.
Check proper wiring and loose
terminals.
Turn off power and manually
rotate pump shaft.
Turn off the power and
discharge the capacitor. Check
with ohm meter (R x 100K).
Use a thermometer to check
the ambient temperature
near the overloads and motor.
Record these values.
Fault
C. Pump cycles too much
D. Fuses blow or circuit
breakers or heaters trip
Troubleshooting Chart
How to fix
Readjust switch or replace if
defective.
Readjust setting (refer to level
control manufacturer’s data).
Replace if defective.
Replace as necessary.
Replace tank with one of cor-
rect size.
Convert PSI to feet (Measured
PSI x 2.31 ft. / PSI = ____ft.)
Refer to the specific pump
curve for that model. Ensure
that total head is sufficient
to limit pump delivery within
its design flow range. Throttle
pump discharge flow is neces-
sary.
If voltage varies more than ±
10%, contact power company.
Check wire sizing.
Increase heater size or adjust
trip setting to a maximum of
motor nameplate (full load)
current.
Must be within ± 5%. If not,
check motor and wiring.
Rotating all leads may elimi-
nate this problem.
If an open or grounded wind-
ing is found, remove the motor,
repair and/or replace.
Tighten loose terminals. Re-
place damaged wire.
If shaft does not rotate eas-
ily, check coupling setting and
adjust as necessary. If shaft
rotation is still tight, remove
pump and inspect. Disass-
emble and repair.
When the meter is connected
to the capacitor, the needle
should jump toward “0” ohms
and slowly drift back to infin-
ity. Replace if defective.
If ambient temperature at
motor is lower than at the
overloads, especially where
temperature at overloads is
above 104°F ambient compen-
sated heaters should replace
standard heaters.

13
English (US)
chapter discard.fm Page 13 Tuesday, June 7, 2011 9:29 PM
LIMITED WARRANTY
Products manufactured by GRUNDFOS PUMPS CORPORATION (GRUNDFOS) are warranted
to the original user only to be free of defects in material and workmanship for a period of
24 months from date of installation, but not more than 30 months from date of manufac-
ture. GRUNDFOS’ liability under this warranty shall be limited to repairing or replacing at
GRUNDFOS’ option, without charge, F.O.B. GRUNDFOS’ factory or authorized service sta-
tion, any product of GRUNDFOS’ manufacture. GRUNDFOS will not be liable for any costs of
removal, installation, transportation, or any other charges which may arise in connection with
a warranty claim. Products which are sold but not manufactured by GRUNDFOS are subject to
the warranty provided by the manufacturer of said products and not by GRUNDFOS’ warranty.
GRUNDFOS will not be liable for damage or wear to products caused by abnormal operating
conditions, accident, abuse, misuse, unauthorized alteration or repair, or if the product was
not installed in accordance with GRUNDFOS’ printed installation and operating instructions.
To obtain service under this warranty, the defective product must be returned to the
distributor or dealer of GRUNDFOS’ products from which it was purchased together with
proof of purchase and installation date, failure date, and supporting installation data. Unless
otherwise provided, the distributor or dealer will contact GRUNDFOS or an authorized service
station for instructions. Any defective product to be returned to GRUNDFOS or a service station
must be sent freight prepaid; documentation supporting the warranty claim and/or a Return
Material Authorization must be included if so instructed.
GRUNDFOS WILL NOT BE LIABLE FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES,
LOSSES, OR EXPENSES ARISING FROM INSTALLATION, USE, OR ANY OTHER CAUSES. THERE
ARE NO EXPRESS OR IMPLIED WARRANTIES, INCLUDING MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE, WHICH EXTEND BEYOND THOSE WARRANTIES DESCRIBED OR REFERRED
TO ABOVE.
Some jurisdictions do not allow the exclusion or limitation of incidental or consequential
damages and some jurisdictions do not allow limitations on how long implied warranties
may last. Therefore, 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 jurisdiction
to jurisdiction.

English (US)
14
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chapter discard.fm Page 17 Tuesday, June 7, 2011 9:29 PM
Grundfos companies
U.S.A.
GRUNDFOS Pumps Corporation
17100 West 118th Terrace
Olathe, Kansas 66061
Phone: [phone]
Telefax: [phone]
Canada
GRUNDFOS Canada Inc.
2941 Brighton Road
Oakville, Ontario
L6H 6C9
Phone: [phone]
Telefax: [phone]
México
Bombas GRUNDFOS de México S.A. de C.V.
Boulevard TLC No. 15
Parque Industrial Stiva
Aeropuerto
Apodaca, N.L.C.P. 66600
Phone: [phone]
Telefax: [phone]

www.grundfos.com
Being responsible is our foundation
Thinking ahead makes it possible
Innovation is the essence
The name Grundfos, the Grundfos logo, and the payoff Be–Think–Innovate are registrated trademarks
owned by Grundfos Management A/S or Grundfos A/S, Denmark. All rights reserved worldwide.
L-EP-TL-002 06.11 US
Repl. 07.04
© 2000, 2004 Grundfos Pumps Corp.
back.fm Page 1 Tuesday, June 7, 2011 9:37 PM