Grundfos S 50 Series User manual

S-pumps, ranges 50 and 54
50/60 Hz
Service instructions
GRUNDFOS INSTRUCTIONS
QR96838602
Installation and operating instructions in
English and other languages for 50/60 Hz
http://net.grundfos.com/qr/i/96838602

English (GB)
2
English (GB) Service instructions
Original service instructions
In this document there are references to the installation and
operating instructions for the S pumps, ranges 50-70 (96838602).
The installation and operating instructions are accessible via the
QR code and link on the front of this document.
CONTENTS
Page
1. Symbols used in this document
1.1 Hazard statements
The symbols and hazard statements below may appear in
Grundfos installation and operating instructions, safety
instructions and service instructions.
The hazard statements are structured in the following way:
1.2 Notes
The symbols and notes below may appear in Grundfos
installation and operating instructions, safety instructions and
service instructions.
1. Symbols used in this document 2
1.1 Hazard statements 2
1.2 Notes 2
2. Safety 3
3. Receiving the product 3
3.1 Transporting the product 3
3.2 Contaminated pumps 3
4. Handling the pump 3
4.1 Lifting the pump 3
4.2 Lifting points 3
4.3 Raising the pump to upright position 4
5. Identification 5
5.1 Nameplates 5
5.2 Approval plates 5
5.3 Type keys 6
6. Torques and lubricants 8
6.1 Common torques 8
6.2 Special torques and lubricants 8
6.3 Quantities of grease in bearings 8
6.4 Motor oil 8
7. Service tools 9
7.1 Standard tools 9
7.2 Special tools 10
7.3 Tightness test tools 10
7.4 Lifting tools 10
8. Service 11
8.1 General information 11
8.2 Servicing pumps with explosion-proof motors 11
8.3 Pump cleaning and visual inspection 11
8.4 Annual maintenance 11
8.5 Oil check and oil change 12
8.6 Inspection and adjustment of impeller clearance 13
8.7 Electrical measurements 13
9. Dismantling and assembly instructions 15
9.1 Checking and replacing the cable 15
9.2 Checking and replacing the protection sensors 16
9.3 Dismantling - S pump 18
9.4 Assembling 19
10. Tightness test 21
10.1 Tightness test of shaft seal housing 21
10.2 Tightness test of stator housing (submerged) 21
11. Drawings 22
11.1 Sectional drawings - motor 22
11.2 Sectional drawings - Pump 26
11.3 Position numbers and material specification 33
11.4 Sensor positions 35
11.5 Electrical connections 36
DANGER
Indicates a hazardous situation which, if not avoided,
will result in death or serious personal injury.
WARNING
Indicates a hazardous situation which, if not avoided,
could result in death or serious personal injury.
CAUTION
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate personal injury.
SIGNAL WORD
Description of hazard
Consequence of ignoring the warning.
- Action to avoid the hazard.
Observe these instructions for explosion-proof
products.
A blue or grey circle with a white graphical symbol
indicates that an action must be taken.
A red or grey circle with a diagonal bar, possibly with
a black graphical symbol, indicates that an action
must not be taken or must be stopped.
If these instructions are not observed, it may result in
malfunction or damage to the equipment.
Tips and advice that make the work easier.

English (GB)
3
2. Safety
For safety reasons, all work in pits must be supervised by a
person outside the pump pit.
Pits for submerged sewage and wastewater pumps contain
gasses and wastewater with toxic and/or disease-causing
substances. Therefore, all persons involved must wear
appropriate personal protective equipment and clothing, and all
work on and near the pump must be carried out under strict
observance of hygienic regulations in force.
3. Receiving the product
3.1 Transporting the product
You can transport the pump in vertical or horizontal position.
Make sure that the pump cannot roll or fall over.
During long periods of storage, the pump must be protected
against moisture and heat.
For further information, see the installation and operating
instructions for S pumps, range 50-70. The installation and
operating instructions are accessible via the QR code and the link
on the front page of this document.
3.2 Contaminated pumps
If a pump has been used for a liquid which is injurious to health or
toxic, the pump will be classified as contaminated.
4. Handling the pump
S pumps weigh up to 520 kg without accessories. It is therefore
very important to use the right lifting equipment.
The pump weight is stated on the pump nameplate. See section
5.1 Nameplates.
4.1 Lifting the pump
All lifting equipment must be rated for the purpose and checked
for damage before any attempt to lift the pump. The lifting
equipment rating must under no circumstances be exceeded. See
section 7.4 Lifting tools.
4.2 Lifting points
Lifting the pump by the power supply cables may result in electric
short circuit and risk of electric shock when the pump is
connected to the mains. The cables and the cable entry may be
damaged, leading to loss of watertightness and consequent
severe damage to the motor.
4.2.1 Lifting points (top)
Use the right lifting point to keep the pump balanced. S pumps
are equipped with a lifting bracket with lifting points ensuring that
the pump can be lifted in a safe manner. See fig. 1and the table
below for the correct lifting points.
Fig. 1 LIfting points for installation types S, C and D
Pump installation in pits must be carried out by
specially trained persons.
Work in or near pits must be carried out according to
local regulations.
DANGER
Crushing hazard
Death or serious personal injury
- Before attempting to lift the pump, make sure the
rated capacity of the lifting equipment (lifting chain
etc.) is adequate for the lifting work. The rated
capacity of the lifting equipment is stated on the
equipment nameplate. The weight of the pump is
stared on the pump nameplate.
WARNING
Crushing of feet
Death or serious personal injury
- Always lift the pump by its lifting bracket or by
means of a fork-lift truck.
CAUTION
Biological hazard
Minor or moderate personal injury
- Flush the pump thoroughly with clean water and
rinse the pump parts in water after dismantling.
DANGER
Electric shock
Death or serious personal injury
- Never lift the pump by the power supply cables.
TM04 7173 1710
Outlet flange size Pump range
50 54
DN 80 Middle Middle
DN 100 Middle Middle
DN 125 Middle Middle
DN 200 Front Front
DN 250 - Front
Front
Middle

English (GB)
4
4.2.2 Lifting points (bottom)
S pumps, ranges 50 and 54, are equipped only with a lifting
bracket on the motor top cover. Use the pump outlet as the lower
lifting point, and lift by means of a lifting strap or a lifting chain
secured below the pump outlet. See fig. 2.
Fig. 2 Lifting points for installation type H
4.3 Raising the pump to upright position
Carelessness during the lifting or transportation may cause injury
to persons or damage the pump.
Fig. 3 Raising the pump to upright position, step 1
Fig. 4 Raising the pump to upright position, step 2
Fig. 5 Raising the pump to upright position, step 3
TM06 5923 0316
DANGER
Crushing hazard
Death or serious personal injury
- Make sure the lifting bracket or strap is tightened
before attempting to lift the pump. Tighten if
necessary.
DANGER
Crushing hazard
Death or serious personal injury
- Do not stand under or next to the pump when
raising it to upright position in order to avoid
crushing in case the pump overturns.
- Make sure the pump is raised gently into upright
position to avoid the lifting chain slipping off the
crane when the pump is not in balance.
TM03 3034 0208
Secure and lift by means of a strap
TM03 3035 0208TM03 3036 0208

English (GB)
5
5. Identification
5.1 Nameplates
5.1.1 Grundfos version
Fig. 6 Nameplate, Grundfos version
5.1.2 Sarlin version
Pumps manufactured in 2001 and before.
Fig. 7 Nameplate, Sarlin version
* Position not used.
5.2 Approval plates
See the installation and operating instructions for S-pumps,
ranges 50-70. The installation and operating instructions are
accessible via the QR code or the link on the front page of this
document.
TM06 0370 5313
Pos. Description
1 Type designation
2 Product number
3 Serial number
4 Maximum head [m]
5 Maximum installation depth [m]
6 Number of phases
7 Voltage, delta connection
8 Voltage, star connection
9 Rated power input [kW]
10 Cos φ, 1/1-load
11 Production code, year and week
12 Production number
13 Maximum liquid temperature [°C]
14 Maximum flow rate [l/s]
15 Enclosure class
16 Frequency [Hz]
17 Rated speed
18 Current, delta connection
19 Current, star connection
20 Rated power output P2
21 Insulation class
22 Net weight [kg]
23 Place of production
1
2
3
4
5
6
7
8
9
10
11
12
23
13
14
15
16
17
18
19
20
21
22
TM03 2548 4505
Pos. Description
1 Type designation
2*
3 Serial number
4*
5 Maximum head [m]
6 Maximum flow rate [l/s]
7 Maximum installation depth [m]
8 Enclosure class
9 Number of phases
10 Frequency [Hz]
11 Rated speed
12 Voltage/current, delta connection
13 Voltage/current, star connection
14 Power input
15 *
16 *
17 *
18 Production code, year and week
19 Pump weight [kg]
20 Fuse rating, delta connection
TYPE
No.
V
A
A
kW
Hz
kg
IP 68
20 m
r/min
HELSINKI FINLAND
3
Q
Hm
l/s
WEIGHT
12
3
1
13
20
6
5
19
18 8
14
10
9
11
7

English (GB)
6
5.3 Type keys
5.3.1 Grundfos version
The S pumps are identified by the type code stated in the order
confirmation and other documentation supplied with the pump.
Please note that the pump type described in this booklet is not
necessarily available in all variants.
Code Explanation Designation
SGrundfos sewage and wastewater
pump Pump type
ST Multi-channel impeller pump
installed in a column pipe
1 Single-channel
Impeller type
2 Two-channel
3 Three-channel
V SuperVortex
100 Maximum solid size [mm] Pump passage
100
Nominal diameter of pump outlet
port [mm]
Pump outlet,
S-type
Nominal diameter of column pipe
[mm]
Pump outlet, ST-
type
55 P2 = Code number from type
designation / 10 Output power [kW]
2 2-pole motor
Number of poles
4 4-pole motor
6 6-pole motor
8 8-pole motor
10 10-pole motor
12 12-pole motor
50 Range 50
Pump range
54 Range 54
58 Range 58
62 Range 62
66 Range 66
70 Range 70
S Super-high
Pressure version
HHigh
MMedium
L Low
E Extra-low
F Super-low
SSubmersible installation without
cooling jacket
Installation type
CSubmersible installation with
cooling jacket
D Dry installation, vertical
H Dry installation, horizontal
205 Impeller diameter [mm] Impeller diameter
(mean)
GCast iron impeller, pump housing
and stator housing
Material code for
impeller, pump
housing and stator
housing
QStainless steel impeller, DIN W.-Nr.
1.4408
SStainless steel impeller and pump
housing, DIN W.-Nr. 1.4408
R
Stainless steel impeller, pump
housing and stator housing, DIN
W.-Nr. 1.4408
N Non-explosion proof pump Pump version
Ex Pump with explosion-proof motor
B
S pump with built-in SM 113
module. PTC sensors are
connected directly to IO 113 or
other PTC relay. Sensor version
C Not in use
DS pump without built-in SM 113
module.
5 50 Hz Frequency [Hz]
6 60 Hz
11
3 x 400 / 690 V, Y/D
(50 Hz only)
Voltage code and
connection
3 x 460 V, Y/D
(60 Hz only)
13 3 x 415 V, Y/D
(50 Hz only)
15 3 x 380 / 660 V, Y/D
(60 Hz only)
GPA Pumps only for Australia Customisation
Z Custom-built products
Code Explanation Designation

English (GB)
7
5.3.2 Sarlin version (old)
Example: S1.X.5.4.H.1.A.5.11.P.Z
* The generation code distinguishes between structurally
different pumps which have the same power rating.
Code Explanation Designation
SGrundfos (or Sarlin) sewage and
wastewater pump Pump type
ST Multi-channel impeller pump
installed in a column pipe
1 Single-channel Impeller type
V SuperVortex
[ ] Standard pump
Pump version
XIn conformity with the ATEX
directive
5 Motor power [kW] Power [kW]
2 2-pole motor Number of poles
4 4-pole motor
[ ] First generation
Generation*2 Second generation
3 Third generation
[ ] No classification
Pressure version
L Low
MMedium
HHigh
1Submersible installation on auto-
coupling
Installation type
2
Submersible installation on auto-
coupling. May operate
continuously with motor
exposed.
3Dry vertical installation with base
stand
4 Submerged installation, portable
5
Submerged installation, portable.
May operate continuously with
motor exposed.
6Horizontal dry installation with
base stand and bracket.
[ ]
No letter indicates full
interchangeability of parts and
use of the same spare parts
catalogue. Interchangeability
A,B,C
The letters (A,B,C,...) indicates
interchangeability of parts
between otherwise identical
pumps.
1 Single-phase Number of phases
[ ] Three-phase
5 50 Hz Frequency [Hz]
6 60 Hz
50 Hz 60 Hz
Voltage code and
connection
01 400 V, DOL 460 V, DOL
03 415 V, DOL 500 V, DOL
05 380 V, DOL
07 220 V, DOL
11 400 V, Y/D 460 V, Y/D
13 415 V, Y/D 500 V, Y/D
15 380 V, Y/D
17 220 V, Y/D
UFlanges Sized According To Ansi
Specifications Special Equipment
ZSee confirmation of order for
further details Non-standard parts

English (GB)
8
6. Torques and lubricants
This section shows the screws and nuts that must be tightened to
a certain torque and the lubricants to be used.
6.1 Common torques
6.2 Special torques and lubricants
Silicone spray Valvoline: 96249498
6.3 Quantities of grease in bearings
Grease: Esso Unirex S2: 96248520
6.4 Motor oil
Motor oil with viscosity grade SAE 10 W 40
Dimension M3 M4 M5 M6 M8 M10 M12 M16 M20 M24
Torque [Nm] 1.1 ± 0.3 2.6 ± 0.6 5.2 ± 1 8.8 ± 2 21 ± 5 42 ± 10 73 ± 15 175 ± 15 350 ± 30 600 ± 30
Range Pos. Description Quantity Dimensions Torque
[Nm] Lubricant
50 67 Screw 1 M10 90 -
54 M12 120 -
50 72a O-ring 1 184.3 x 5.7 -Oil
54 219.3 x 5.7
All - Shaft end - - - Silicon spray
All 105
O-ring (stationary part) 1 45.69 x 2.62 - Oil
O-ring (rotating part) 1 37.77 x 2.62 1 Oil
Set screw 3 - 6 -
All 105b
O-ring (stationary part) 1 61.6 x 2.62 - Oil
O-ring (rotating part) 1 50.47 x 2.62 - Oil
Set screw 3 - 6 -
Range Bearing Amount of grease
50 Lower bearing 0.105 litres
54 0.240 litres
Range Bearing Amount of grease
50 Upper bearing 0.058 litres
54 0.160 litres
Range Installation type Amount of motor oil
50 S 2.6 litres
C and H 1.9 litres
54 S 3.5 litres
C, D and H 2.5 litres

English (GB)
9
7. Service tools
The following table shows standard and special tools for pump service.
7.1 Standard tools
Standard tools
ABCD
EFGH
IJKM
Pos. Range Designation
A All Hexagon head driver
B All Ratchet handle 1/2"
C All Screwdriver
D All Hexagon key
E All Plastic hammer
F All Puller for bearing
G All Ring/open-end spanner
H All Pinch bar
I 54 Lock-ring pliers
J 54 Multimeter
KAllCaliber
MAllTorquewrench

English (GB)
10
7.2 Special tools
Special tools
7.3 Tightness test tools
Tightness test tools
7.4 Lifting tools
Lifting tools
NOPQ
R
Pos. Range Designation Description Part number
N50 Seal assembly tool for secondary shaft seal (PUR114) 38 mm 96061558
O Seal assembly tool for primary shaft seal (PUR125) 32 mm 96061566
P54 Seal assembly tool for secondary shaft seal (PUR115) 50 mm 96061559
Q Seal assembly tool for primary shaft seal (PUR124) 38 mm 96061565
R All Bearing heater - -
TU
Pos. Designation Description Part
number
T Pressure gauge - -
UTest plug (KOE045)
2 pcs.
Connector M3\8-24
UNF F-ISO 228-G 3\8M 96061209
V
Pos. Designation Description Part
number
V Eye bolt All -
BAR

English (GB)
11
8. Service
8.1 General information
Service must be carried out by specially trained persons. Before
carrying out maintenance and service, it must be ensured that the
pump has been thoroughly flushed with clean water. Rinse the
pump parts with water after dismantling.
Before assembly:
• Clean and check all parts.
• Replace defective parts with new parts.
• Order the necessary service kits.
• Always replace the gaskets and O-rings when the pump is
overhauled.
During assembly:
• Lubricate and tighten screws and nuts to the correct torque as
stated in section 6. Torques and lubricants.
8.2 Servicing pumps with explosion-proof motors
Intervention in the flameproof enclosure of the pump is only
allowed for authorised Ex workshops.
Service not affecting the explosion protection of the pump is
allowed without violating Ex regulations.
Consequently, service persons who are not Ex authorised are
allowed to replace the following parts of explosion-proof pumps:
• pump housing
•impeller
• shaft seal.
All other service work must be carried out by an authorised Ex
workshop. Violation of this requirement will invalidate the Ex
classification of the pump.
8.3 Pump cleaning and visual inspection
A simple maintenance measure is to clean the pumps at regular
intervals. The pumps may be cleaned on site at the pumping
station when lifted up from the wet pit. Hose down the pump
externally using a high-pressure jet cleaner (maximum pressure
100 bar). Caked dirt on the motor must be removed to ensure
good heat conductivity. A mild detergent approved for disposal
into the sewage system may be used. The pumps may be
scrubbed using a soft brush, if necessary.
Visual inspection of the pump must include search for cracks or
other external damage. Inspect the lifting bracket and lifting chain
for wear and corrosion. Inspect the pump cable for cracks or
lacerations in the sheath, kinks or other damages. Inspect visible
parts of the cable entry for cracks and for being firmly connected
to the motor top cover. Check all visible screws and tighten, if
necessary.
The air vent valve at the top of the cooling jacket may be removed
and cleaned, if necessary. Clean the vent hole before refitting the
valve after cleaning.
8.4 Annual maintenance
Pumps in normal operation must be inspected once a year. If the
pumped liquid is very muddy or sandy, check the pump at shorter
intervals.
Check the following points:
•Power consumption
See section 5.1 Nameplates.
•Oil level and oil condition
See section 8.5 Oil check and oil change.
• Electrical measurements
See section 8.7 Electrical measurements.
•Cable entry
Make sure that the cables are not sharply bent or pinched.
Replace the cables if necessary.
See section 9.1 Checking and replacing the cable.
•Sensors
Make sure that the sensors are working. Replace the sensors
if necessary.
See section 9.2 Checking and replacing the protection
sensors
•Impeller clearance
Check the impeller clearance.
See section 8.6 Inspection and adjustment of impeller
clearance.
•Pump parts
Check the pump housing etc. for wear. Replace defective
parts.
•Ball bearings
Check the shaft for noisy or heavy operation (turn the shaft by
hand). Replace defective ball bearings.
A general overhaul of the pump is usually required in case of
defective ball bearings or poor motor function. This work must
be carried out by an authorized service workshop.
•O-rings and similar parts
During service/replacement, it must be ensured that the
grooves for O-rings and seal faces have been cleaned before
the new parts are fitted.
DANGER
Electric shock
Death or serious personal injury
- Before starting work on the pump, make sure that
the mains switch has been locked in position 0.
Make sure that the power supply cannot be
accidentally switched on.
WARNING
Crushing of hands
Death or serious personal injury
- Make sure that all rotating parts have stopped
moving.
Except for replacement/dismantling of bearings, all
other service work must be carried out by Grundfos
or an authorised service workshop.
On Ex pumps, the ball bearings must only be
replaced by an authorised Ex workshop.
Do not reuse used rubber parts.

English (GB)
12
8.5 Oil check and oil change
The oil chamber is filled with oil acting as lubricant and coolant for
both mechanical seals.
A low oil level may indicate that the upper mechanical shaft seal
is defective. Contact an authorised service workshop for further
overhaul of the pump and repair, if required.
The oil in the oil chamber can be changed with the pump in either
horizontal or upright position. We recommend that you carry out
the oil change with the pump in horizontal position, if possible,
because in that way it is much easier to drain all the used oil out
of the chamber.
Horizontal position
Proceed as follows:
1. Place the pump in such a position that screw A is pointing
downwards.
Fig. 8 Pump with oil plugs
2. Place a clean container under the pump to collect all the
drained-off oil. Loosen the screw A.
3. When the oil starts to drill out, remove the plug A.
4. Remove the screw B.
5. Take an oil sample to inspect the condition of the oil. The oil
becomes greyish white like milk if it contains water. In normal
operation a small leakage through the mechanical shaft seals
is expected to happen, but if the water content in the oil is
high, this may be the result of a defective shaft seal.
Change the oil if it contains water. Oil not containing water can
be reused. Emulsified oil must be changed and disposed of.
6. For oil filling, place the pump in such a position that the
screws A and B are pointing upwards.
7. Fit the screw A including the O-ring.
8. Fill with oil.
9. Fit the screw B including the O-ring.
Upright position
Proceed as follows:
1. Identify the screws A and B and their positions relative to each
other. See fig. 8.
Fig. 9 Correct oil level of upright position
2. Use screw B for indication of the level of oil in the oil chamber.
See fig. 9.
3. When the pump is upright, the oil has to be pumped out of the
oil chamber. Use a suction pump with a flexible suction hose
that can be inserted deeply into the oil chamber.
4. Pump out the oil using all the screw holes in turns so as to
reach all sections of the interior of the oil chamber. Collect the
drained oil in a clean container.
5. Replace the O-rings. Fill the oil chamber with oil to the correct
level. Refit screws A and B and tighten securely.
Lack of oil may cause overheating and damage of
the mechanical seals. The WIO sensor in the oil
chamber will trip the alarm if the oil quality is poor or
if there is no oil in the oil chamber.
TM06 7493 3516
CAUTION
Pressurised system
Minor or moderate personal injury
- When loosening the screw of the oil chamber, note
that pressure may have built up in the chamber. Do
not remove the screw until the pressure has been
fully relieved.
A
B
Used oil must be disposed of in accordance with
local regulations.
TM02 4005 4601
AB

English (GB)
13
8.6 Inspection and adjustment of impeller clearance
The correct axial clearance is 0.7 mm ± 0.2. Reset the clearance
if it is 0.7 mm or more. The method for resetting the clearance is
different for submersible pumps, installation types S, C and ST,
and for dry-installed pumps, installation types D and H. For dry-
installed pumps there are two methods.
All methods are described here.
8.6.1 Submersible pumps, installation types S, C and ST
Submersible pumps have a separate, adjustable pump inlet cover
which may be shaped as an inlet bell. When the pump is installed
or pulled out of the pit for service, locate the six fastening screws
of the inlet cover and the three set screws.
Use a feeler gauge to check the clearance between the impeller
and the inlet cover all around the perimeter of the inlet opening.
See fig. 10.
Fig. 10 Impeller clearance adjustment
8.6.2 Dry-installed pumps, Installation types D and H
Proceed as follows:
1. Loosen the set screws by two full turns each.
2. Close the impeller clearance by lightly tightening the fastening
screws diagonally until the impeller touches the pump
housing.
3. Loosen the fastening screws to make an 0.7 mm gap under
the heads of the fastening screws. See fig. 10.
4. Tighten the set screws tightly.
5. Tighten the fastening screws diagonally.
8.7 Electrical measurements
In case the cable is damaged, measure from the cable terminal
with the cable disconnected.
Connections in the terminal boards are accessible by hand once
the motor has been removed. See section 9. Dismantling and
assembly instructions.
8.7.1 Checking the internal motor control devices
1. Connect tester (test bell, test lamp etc.) to leads P1 and P2 (1
and 2).
2. If tester functions (bell rings, lights come on) the control circuit
is closed and intact.
8.7.2 Checking the earth connection
1. Connect one tester to the earth lead (yellow-green wire).
2. Connect second tester to the pump body.
3. In case the tester functions, the earth connector is in order.
In case the tester doesn’t function, the earth connector is
faulty and must be repaired.
8.7.3 Checking the insulation resistance
Insulation resistance can be measured from the cable end
(control cabinet) or from the stator wires. Use a tester that can
apply at least 500 VDC.
1. Measure the insulation resistance. As a minimum there must
be 100 MΩbetween:
– earth (body) to phases U, V and W
– earth (body) to control circuit leads P1 and P2 (1 and 2)
– control circuit leads P1 and P2 to phases U, V and W
– between phases.
2. If any of the above-mentioned measurements are below 100
MΩ, measure cable, windings and devices separately to find
out where the insulation resistance has decreased.
Reduction of insulation resistance due to moisture requires
drying of the relevant parts, see sections 8.7.5 Drying of the
cable and 8.7.6 Drying of the stator and rotor.
3. Check that the conductor markings are indicated at the end of
the cables.
It is not possible to adjust the clearance of SV
pumps.
You can check the impeller and pump housing for
wear only.
TM05 1916 3911
Do not use too much force when tightening the
fastening screws as this may damage the bearings.
The movement is usual 1 to 3 mm.
Set screw
0.7
Fastening screw Fastening screw
DANGER
Electric shock
Death or serious personal injury
- The pump must not be connected to the mains if
the earth connection is not intact.
Do not connect the tester to the cooling jacket, if any.

English (GB)
14
8.7.4 Checking the stator winding resistance
The measurements can be performed with a reliable multimeter
that is capable of measuring Ω-values with 3 digit accuracy.
The maximum allowed difference between phases is ± 10 %.
Proceed as follows:
1. Disconnect the stator winding wire ends from the terminal
board.
2. Identify the wire markings and proceed according to step 3 or
step 4.
Step 3 applies only for the wires marked with the letters U, Vand
W.
3. Measure the stator winding resistance between:
– U1 and U2
– V1 and V2
– W1 and W2.
Step 4 applies only for the wires marked with the letter T.
4. Measure the stator winding resistance between:
– T1 and T4
– T2 and T5
– T3 and T6
– T7 and T8 (2 phases in series)
– T8 and T9 (2 phases in series)
– T9 and T7 (2 phases in series).
5. Compare the measured values to the values in the winding
resistance value table. See section 11.5.1 Cable and winding
resistances. In case of 2 phases in series, the measured
values need to be divided by 2 before comparing them to the
values in the tables.
If no or only very few readings are obtained, the stator must
be dried before the measurements are carried out again. See
section 8.7.6 Drying of the stator and rotor.
Consistent false reading of the stator winding resistance
values is sufficient evidence of a winding damage. In case the
stator needs to be replaced, see section 9. Dismantling and
assembly instructions.
8.7.5 Drying of the cable
1. See section 9.3.5 Removing the motor top cover.
2. See section 9.1 Checking and replacing the cable.
3. Blow clean air (max. 0.8 bar) through the cable.
4. Dry for approx. 20 hours.
5. Connect the old cable or replace it with a new one.
6. Measure the resistance. See section 8.7.3 Checking the
insulation resistance.
8.7.6 Drying of the stator and rotor
1. See section 9.3 Dismantling - S pump.
2. Place the stator and rotor in an oven at 100-110 °C.
3. Dry for 6 to 12 hours.
4. Let the stator and rotor cool down.
5. Measure the winding resistance.
If the measurements are not valid, replace the stator. See
section 9.4 Assembling.
Always disconnect the stator winding wires from the
terminal board before measuring resistance values
from them.
Make sure that the cables are disconnected from the
terminal board before removing the cable entry.
If the stator is wet, not only the stator but also the
rotor must be dried. If this is not done, the stator may
become moist again after re-assembly and trip the
moisture switch.

English (GB)
15
9. Dismantling and assembly instructions
Position numbers of parts (digits) refer to section 11. Drawings
and section 11.3 Position numbers and material specification,
and position numbers of tools (letters) refer to section 7. Service
tools.
9.1 Checking and replacing the cable
Make sure that the cables are not sharply bent or pinched and
that the cable sheath has no visual defects.
Disconnect the cable - composite cable entry (non-Ex)
Fig. 11 Cable entry attached to motor top cover
1. See section 9.3.4 Removing the cooling jacket.
2. See section 9.3.5 Removing the motor top cover.
3. Remove the screws (181a). See fig. 11.
4. Pull the cable (181) including the cable entry assembly out of
the motor top cover (164a).
5. Remove the cable entry (168) including the rubber seal (198)
and cable clamp (180), if any, from the cable (181).
6. Remove the rubber seal (198) from the cable entry (168).
7. Remove the cable clamp (180) from the cable entry (168).
Connecting the new cable - composite cable entry (non-Ex)
1. Slide the cable entry (168) on the cable (181).
2. Slide the cable clamp (180) and rubber seal (198) on the
cable (181).
3. Fit the cable clamp (180) and rubber seal (198) on the cable
entry (168).
4. Fit the cable entry to the motor top cover (164) with screws
(181a).
5. Tighten the screws (181a) evenly with to the torque specified
in section 6. Torques and lubricants.
Disconnect the cable - metal cable entry (non-Ex/Ex)
Fig. 12 Cable entry attached to motor top cover
1. See section 9.3.4 Removing the cooling jacket.
2. See section 9.3.5 Removing the motor top cover.
3. Remove the screws (180a). See fig. 12.
4. Remove the cable clamp (180).
5. Remove the screws (181a).
6. Pull the cable (181) including the cable entry assembly out of
the motor top cover (164a).
7. Remove the cable entry (168) including the rubber seal (198)
and washer (185), if any, from the cable (181).
8. Remove the rubber seal (198) from the cable entry (168).
There are several service videos available as
guidance on Grundfos Product Center or YouTube.
Always use original service parts from the
manufacturer.
Do not disassemble the cable entry, unless you are
going to replace it.
Disconnecting the cables will shorten them
significantly.
TM06 7485 3516
Make sure that the cables are disconnected from the
terminal board before removing the cable entry.
181a
181
198
164
168
180
To prepare a new cable (length of leads, cable clips,
cable markings, etc.), please use the old cable as
reference.
Connect according to the wiring diagrams.
TM06 7216 3016
Make sure that the cables are disconnected from the
terminal board before removing the cable entry.
181
168
180
180a
198
164a
181a
185

English (GB)
16
Connecting the new cable - metal cable entry (non-Ex/Ex)
1. Measure (K) the outer diameter of the cable (181) and the
hole diameter (cable ID) from the motor top cover (164a).
Check the number of washers (185) needed, if any, in the
table below.
2. Slide cable entry (168) on the cable (181).
3. Fit the cable entry (168), washer(s) (185) and rubber seal
(198) on the cable (181).
4. Fit the cable entry to the motor top cover (164a) with screws
(181a).
5. Tighten the screws (181a) evenly to the torque specified in the
table above.
6. Fit the cable clamp (180a) to the cable entry (168) with screws
(180a).
9.2 Checking and replacing the protection sensors
9.2.1 Moisture switch
The standard pumps have one moisture switch under the motor
top cover. The Ex pumps have two moisture switches: one under
the motor top cover and one in the stator housing. On Ex pumps
manufactured before February 2009, both moisture switches are
placed under the motor top cover
The changing method is the same, no matter where the switch is
placed.
Checking the moisture switch
1. Connect the switch to a simple bell circuit or another test
circuit.
2. Adjust the clearance between the expander part and the
switch body to 2.5 mm using the adjustment gauge
3. Remove the adjustment gauge.
Checking the microswitch
1. Connect the test bell or another test circuit.
2. Place the adjustment gauge between the expander part and
the switch body.
3. Pull the expander outward two to three times to make sure
that the bell stops ringing (the electric circuit will be broken)
when the expander is pulled outward and starts to ring when
the expander is free.
Adjusting the clearance of the moisture switch
1. Place the adjusting gauge between the expander part and the
switch body.
2. Pull the expander outward:
– If the bell rings, turn the adjusting screw clockwise until the
bell stops ringing
– If the bell is not ringing, turn the adjusting screw
counterclockwise until the bell starts ringing.
3. Remove the adjustment gauge
4. Install the switch, and test the microswitch.
Fig. 13 Moisture switch
Removing the moisture switch
1. Disconnect the spade connectors from the switch.
2. Remove the mounting screw and lock washer from the
mounting bracket. Remove the switch.
3. Remove the screw.
4. Remove the switch from the mounting bracket.
To prepare a new cable (length of leads, cable clips,
cable markings, etc.), please use the old cable as
reference.
Cable ID
[mm-ver.]
Cable [mm] Washer
[pcs.] Torque [Nm]
min. max.
36-1 14.4 15.4 -
10
15.4 16.4 1
36-2
17.2 17.5 -
17.5 18.8 1
18.8 20.0 3
46-1 15.7 17.2 -
45
46-2
17.8 18.5 -
18.5 19.2 1
19.2 20.0 2
46-3
20.9 21.5 -
21.5 22.4 1
22.4 23.4 3
46-4
23.8 24.6 -
24.6 26.0 2
26.0 27.0 5
If a gap remains between the motor top cover and
cable gland/washer wait for 30-60 minutes and
retighten the screws.
Connect according to the wiring diagrams.
Do not touch the head of the moisture switch with wet
or oily hands. Moisture on the sensor head before
installation will lead to false measuring values.
TM06 7199 3016
Spade connectors
Mounting screw
and lock washer
Mounting bracket
Screw
Expander part
Switch body

English (GB)
17
Fitting a new moisture switch
The moisture switch must be stored in the sealed packaging to
protect the expander part from humidity. The relay is set at the
factory and must be checked and re-set before it is installed.
5. Fit the moisture switch to the mounting bracket.
6. Fit the screw to attach the switch to the mounting bracket.
7. Fit the mounting bracket including the switch on the base with
the mounting screw and the lock washer.
8. Connect the spade connectors.
9. Connect the wires according to the wiring diagram. See
section 11.5.3 Wiring diagrams.
9.2.2 Pt100 sensor on lower bearing bracket
Fig. 14 Pt100 sensor on lower bearing bracket
Removing Pt100
1. Cut the wire of the Pt100 sensor right next to sensor. Remove
the wire.
2. Drill out the sensor from the lower bearing bracket (155).
Fitting new Pt100
3. Dip the sensor head in glue and insert it into the hole in the
lower bearing bracket (61).
4. Connect according to the wiring diagram. See section
11.5.3 Wiring diagrams.
9.2.3 Pt100 sensor on the stator
Removing Pt100
1. Cut the wire of the Pt100 sensor right next to the sensor and
remove the wire.
2. Leave the old sensor on the stator.
Fitting new Pt100
3. Glue the sensor onto the stator windings (48).
4. Connect according to the wiring diagram. See section
11.5.3 Wiring diagrams.
9.2.4 Water-In-Oil sensor (WIO)
Fig. 15 External Water-In-Oil sensor (WIO)
Removing the WIO sensor
1. Place the pump in vertical position.
2. Loosen the cable inlet and carefully pull the sensor out of the
oil chamber.
3. Replace immediately with new sensor or the oil plug (193) and
the O-ring (194).
Fitting new WIO sensor
Fig. 16 Installation of WIO sensor
1. Fit the WIO sensor in the hole of oil plug B. See figs 8and 9
for correct position. Make sure that the sensor head is inside
the oil chamber. See installation length above.
2. Connect according to the wiring diagram. See section
11.5 Electrical connections.
The moisture switch must be removed from its
packaging one day prior to re-setting, to give
sufficient time for the expander part to adjust itself to
the local humidity level.
TM06 7556 3616
Make sure that the wire of the new sensor is
protected by a protection sleeve.
Pt100
TM06 7248 3116
We recommend to change the motor oil in case the
WIO sensor is changed.
TM03 5531 0617
Range Installation length [L]
50 80 mm
54 90 mm
L

English (GB)
18
9.3 Dismantling - S pump
For position numbers, see section 11. Drawings.
9.3.1 Removing the pump housing and impeller
The tools are shown in section 7. Service tools.
1. Place the pump in vertical position and support it by means of
a hoist fastened to the lifting bracket (190).
2. Remove the screws (26) in the pump housing (50).
3. Lift the motor including the impeller (49) out of the pump
housing (50).
If necessary, tap all around the housing with a soft hammer to
remove the motor or pry it loose with a pry bar.
4. Place the motor in horizontal position on a firm workbench or
trestle with the impeller facing outward.
5. Remove the impeller screw (67). For some non-SuperVortex
pumps it is necessary to use an impact puller (M) to remove
the impeller cap.
6. Remove the impeller (49).
7. Remove the key (9a)
9.3.2 Draining the oil
1. See section 8.5 Oil check and oil change.
9.3.3 Removing the primary shaft seal
1. See section 9.3.1 Removing the pump housing and impeller.
2. See section 9.3.2 Draining the oil.
3. Loosen the set screws in the shaft seal (105), and remove the
rotating part.
Step 4 is only valid for pumps manufactured from October 2008.
4. Remove the locking ring and washer.
5. Gently remove the stationary ring of the shaft seal (105).
9.3.4 Removing the cooling jacket
1. Remove the screws (190b) and the lifting bracket (190).
2. Remove the screws (150a).
3. Pull out the cooling jacket (150) from the brackets with a hoist.
4. Remove O-rings (157b and 37a)
9.3.5 Removing the motor top cover
1. Remove the screws (178) and the lifting bracket (190).
2. Remove the cooling jacket, if any.
3. Lift out the motor top cover (164a). Tap lightly, if needed.
4. Disconnect the cables.
5. Remove the motor top cover (164a).
6. Remove O-ring (157).
9.3.6 Removing the shaft seal housing
1. See section 9.3.3 Removing the primary shaft seal.
2. Remove the screws (184) in the stator housing (55).
3. Remove the seal housing (58).
9.3.7 Removing the secondary shaft seal
1. See section 9.3.6 Removing the shaft seal housing.
2. Loosen the set screws in the secondary shaft seal (105b).
3. Remove the rotating and stationary parts of the shaft seal
(105b) from the shaft. Use wedges if needed.
9.3.8 Removing the rotor
1. See section 9.3.7 Removing the secondary shaft seal.
2. Remove screws (184b) (Ex pumps only).
3. Insert an eyebolt into the shaft end.
4. Lift the rotor assembly off the stator housing (55) using a
hoist. The upper bearing comes out together with the rotor
assembly.
5. Remove O-ring (72a).
6. Place the rotor assembly in horizontal position.
7. Remove the circlip (188) and the washer (197).
8. Remove the eyebolt from the shaft end.
9.3.9 Removing the lower bearings
1. See section 9.3.8 Removing the rotor.
2. Pull off the lower bearing bracket (155) at the non-drive end
(F).
3. Remove the ball bearings (153) from the shaft. (F)
4. Remove the circlip (187) and the washer (187a).
5. Remove the upper bearing bracket cover (60).
9.3.10 Removing the upper bearing
1. See section 9.3.8 Removing the rotor.
2. Pull out the bearing (154) from the shaft.
Maintenance and service work on explosion-proof
pumps must be carried out by Grundfos or a service
workshop authorised by Grundfos.
Handle seal parts with extreme care to prevent
damage. Be very careful not to damage the
precision-finished seal faces; even fingerprints can
shorten the seals life.
CAUTION
Sharp element
Minor or moderate personal injury
- Cover the sharp edges of the keyway on the shaft,
for instance with tape.
We recommend drawing a marking on the stator
housing (55) and lower bearing bracket (155) so that
you are able to position the lower bearing bracket
correctly at the assembly.

English (GB)
19
9.3.11 Removing the upper bearing bracket
1. Disconnect the sensor cables from the terminal block (176c).
2. Remove the moisture absorbing bag.
3. Place the screw in the screw hole in the upper bearing bracket
(61). Use M10 for range 50 and M12 for range 54.
4. Turn the screw into the hole so that the upper bearing bracket
(61) starts to pull up.
5. Remove the upper bearing bracket (61) and the screw.
9.3.12 Removing the stator
If the stator package is reused the support ring must be placed
below the stator package to avoid break down.
Fig. 17 Removing stator
1. Lift the stator slightly off the floor.
2. Heat the stator housing (55) at the same time with 2 or 3 gas
burners beginning from the bottom edge. See fig. 17.
3. Carry out the heating as quickly as possible. The stator
package (48) will drop to the floor when enough heat has
been applied.
9.4 Assembling
The torques for the screws and the lubricants for the O-rings are
shown in section 6. Torques and lubricants.
9.4.1 Fitting the stator
Fig. 18 Fitting the stator
1. Check that the assembly ring is high enough (dimension H)
for the stator package.
2. Curl the cables inside the stator package.
3. Place the stator package (48) on the assembly ring.
4. Heat the stator housing (55) to 200-250 °C with gas burners or
in a oven.
5. Fit the lifting eyes and secure it to the stator housing (55) with
bolts.
6. Lift the heated stator housing (55) over the stator (48) and
lower it carefully onto the stator (48). Make sure the position is
correct.
7. Check the assembly dimension A.
9.4.2 Fitting the rotor
1. Fit and lubricate the O-ring (72a).
2. Lift the rotor assembly into the stator housing (55) using a
hoist.
Make sure to position the rotor assembly in accordance with
the marking made during dismantling so that the oil holes of
the oil cover are positioned directly above the oil holes of the
seal housing.
3. Carefully tap on the lower bearing bracket (155) into the stator
housing (55).
4. Fit the washer (197) and the circlip (188).
5. Fit the screws (184b) (Ex pumps only).
TM06 7906 4716
Make sure you use suitable protection equipment.
TM06 8133 4716
Range Lamination length L
[mm]
Assembly
ring height H
[mm]
Stator
wires
Assembly
dimension
A [mm]
50 All min. 205 Down 74
54 All min. 220 97
A
H
L

English (GB)
20
9.4.3 Fitting the upper bearing
1. Heat up the ball bearing (154) to 110 °C and fit it on the shaft.
2. Let the assembly cool down.
3. Grease the ball bearing (154). Fill only 50 % of the free space
of the bearing.
9.4.4 Fitting the lower bearing
1. Place the rotor in vertical position with the shaft end pointing
upwards.
2. Fill the bearing bracket cover (60) with grease and place the
cover on the shaft so that it is lying against the rotor.
3. Place the washer (187a) and the circlip (187) on the shaft.
4. Heat up the ball bearing to 110 °C and fit it on the shaft.
5. Let the assembly cool down.
6. Grease the ball bearing (153). Fill only 50 % of the free space
of the bearing.
7. Heat up the lower bearing bracket (155) to 110 °C and press it
home.
8. Turn the assembly so that the shaft end points downwards.
9. Fit the bearing bracket cover (60) to the lower bearing bracket
cover (155).
9.4.5 Fitting the secondary shaft seal
1. Place the motor in vertical position so that the shaft end points
upwards.
2. Make sure that the shaft is clean and smooth.
3. Fit the O-ring on the stationary part of the secondary shaft
seal (105b).
4. Lubricate the O-ring and fit the stationary part on the
secondary shaft seal (105b) on the shaft and press it home
(50: Oand 54: Q).
5. Check that the O-ring is fitted on the rotating part of the
secondary shaft seal (105b).
6. Fit the rotating part of the secondary shaft seal (105b) on the
shaft and press it home (50: Oand 54: Q).
7. Tighten the set screws in the secondary shaft seal (105b) to a
torque of 6 Nm.
8. Remove the PUR-tool and the set-up clip from the secondary
shaft seal (105b).
9.4.6 Fitting the shaft seal housing
1. Fit and lubricate the O-ring (72).
2. Fit the shaft seal housing (58) on the stator housing (55).
3. Fit the screws (184).
9.4.7 Fitting the upper bearing bracket
1. Fit the O-ring (157b) to the upper bearing bracket (61).
2. Pull the stator cables through from the cable holes.
3. Fit the upper bearing bracket (61) to the stator housing (55).
If needed, tap gently.
4. Connect according to the wiring diagram. See section
11.5 Electrical connections.
5. Fit the absorbing bag.
9.4.8 Fitting the motor top cover
1. Fit the O-ring (157) on the motor top cover (164a).
2. Place the cover near the motor (301) and connect the cables
according to the wiring diagram. See section 11.5 Electrical
connections.
3. Fit the motor top cover (164a). Tap gently, if needed.
4. Fit the screws (178).
9.4.9 Fitting the cooling jacket
1. Fit the O-rings (37a and 157b).
2. Mount the cooling jacket (150c) on the stator housing (55)
using a hoist. Tap gently, if needed.
3. Fit the screws (150a).
4. Fit the lifting bracket (190) and the screws (190b).
9.4.10 Fitting the primary shaft seal
1. Make sure that the shaft is clean and smooth.
2. Fit the O-ring on the stationary part of the primary shaft seal
(105).
3. Lubricate the O-ring and fit the stationary part on the
secondary shaft seal (105) on the shaft.
Make sure that the gap in the stationary part meets the
projection on the lower bearing bracket (155).
4. Press the stationary part of the primary shaft seal home (105)
(50: Oand 54: Q).
5. Check that the O-ring is fitted on the rotating part of the
primary shaft seal (105).
6. Fit the rotating part of the primary shaft seal (105b) on the
shaft.
7. Fit the set-up clip between the seal parts and press the
rotation part of the seal home (50: Oand 54: Q).
8. Tighten the set screws in the primary shaft seal (105) to a
torque of 6 Nm.
9. Remove the PUR-tool and the set-up clip from the primary
shaft seal (105b).
10. See section 10.1 Tightness test of shaft seal housing.
9.4.11 Oil filling
See section 8.5 Oil check and oil change.
9.4.12 Fitting the impeller and pump housing
1. Fit the key (9a). Tap lightly, if needed.
2. Lubricate the cone of the shaft slightly.
3. Fit the impeller (49).
4. Fit the screw (67). Tighten to the torque specified in section
6.2 Special torques and lubricants
5. Mount the motor on the pump housing (50).
6. Fit the screws (26).
7. Check the impeller clearance. See section 8.6 Inspection and
adjustment of impeller clearance.
Only press on the inner ring of the bearing.
The pump must be fully assembled and closed
withing one hour after the new moisture absorbing
bag has been exposed to the atmospheric humidity.
Check the possible leak paths with leak detecting
liquid.
Tightness of complete motor must be verified through
a submersion test.