Grundfos CM series Operating instructions

CM, CME
Service instructions
GRUNDFOS INSTRUCTIONS

CM, CME
English (GB)
Service instructions ........................................................................4
3
Table of contents

English (GB) Service instructions
Original service instructions
Table of contents
1. General information ........................4
1.1 Hazard statements..........................4
1.2 Notes ..................................4
2. Type identification .........................5
2.1 Nameplate...............................5
2.2 Type key ................................6
2.3 Key to codes .............................6
3. Tightening torques and lubricants ...............8
4. Service tools .............................9
4.1 Standard tools ............................9
4.2 Torque tools ..............................9
5. Dismantling and assembly ...................10
5.1 General information ........................10
5.2 CM 1, 3, 5, cast iron ........................10
5.3 CM 1, 3, 5, stainless steel ....................12
5.4 CM 10, 15, 25, cast iron......................14
5.5 CM 10, 15, 25, stainless steel ..................15
5.6 MG 71 and MG 80 motors ....................17
5.7 MG 90, MG 100, MG 112 and MG 132 motors ........17
5.8 Checking and replacing impellers and chambers ......18
5.9 Replacement of impellers and spacing pipes .........18
6. Fault finding ............................19
6.1 The pump does not run.......................19
6.2 Motor-protective circuit breaker has tripped (trips out
immediately when supply is switched on)............19
6.3 The motor-protective circuit breaker trips out
occasionally..............................20
6.4 The motor-protective circuit breaker has not tripped out,
but the pump is inadvertently out of operation. ........21
6.5 The pump performance is unstable. ..............21
6.6 The pump runs, but gives no water. ..............21
6.7 The pump runs backwards when switched off. ........21
6.8 The pump runs with reduced performance. ..........21
7. Drawings ..............................22
7.1 CM 1, 3, 5 ..............................22
7.2 CM 10, 15, 25............................24
8. Order of assembly for chambers and impellers .....26
8.1 Key for CM 1, 3, 5 .........................26
8.2 CM 1, 3, 5, cast iron ........................26
8.3 CM 1, 3, 5, stainless steel ....................26
8.4 Key for CM 10, 15, 25 .......................27
8.5 CM 10, 15, 25, cast iron......................27
8.6 CM 10, 15, 25, stainless steel ..................28
1. General information
Read this document before you install the product. Instal-
lation and operation must comply with local regulations
and accepted codes of good practice.
1.1 Hazard statements
The symbols and hazard statements below may appear in Grundfos
installation and operating instructions, safety instructions and
service instructions.
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.
The hazard statements are structured in the following way:
SIGNAL WORD
Description of the hazard
Consequence of ignoring the warning
• Action to avoid the hazard.
1.2 Notes
The symbols and notes below may appear in Grundfos installation
and operating instructions, safety instructions and service
instructions.
Observe these instructions for explosion-proof products.
A blue or grey circle with a white graphical symbol indi-
cates 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 mal-
function or damage to the equipment.
Tips and advice that make the work easier.
4
English (GB)

2. Type identification
This section shows the nameplate, the type key and the codes that can appear in the variant code.
As codes can be combined, a code position may contain more than one code (letter).
2.1 Nameplate
Model
IP T
TypeP
max
T
liq,max
barMPa PSI
Q nom
H nom
H max
m³/hGPM
Env
m
m
PSI
PSI
Q nom
H
nom
H max
m³/hGPM
m
m
PSI
PSI
°C °F
50 Hz
95120839
60 Hz
3455
6
77
89
10 10
11 11
12 12
66
1
10
11
12
10
11
12
2
Amb
°C °F
Insulation class
TM040355
Pump nameplate
Imax
~ / V
/ A
/ A
uF / V
kW
95120836
I1/1
P2
Imax
~ / V
/ A
/ A
I1/1
P2
Capacitor
HP kW HP
uF / V
Capacitor
50 Hz 60 Hz
1 12
3
4
5
2
3
4
5
2
3
4
5
2
3
4
5
6 6
TM040356
Motor nameplate
The pump and motor nameplates are positioned on the motor fan cover or terminal box.
The data and information on the pump nameplate are described in the table below.
Pos. Description
1 Pump type
2 Pump model
3 Environmental rating for enclosures based on NEMA type designations
4 Enclosure class
5 Maximum ambient temperature [°C] / [°F]
6 Maximum system pressure [bar] / [psi] / [MPa]
7 Maximum liquid temperature [°C] / [°F]
8 Insulation class
9 Motor protection
10 Rated flow [m3/h] / [GPM]
11 Head at rated flow [m] / [psi]
12 Maximum head [m] / [psi]
The data and information on the motor nameplate are described in the table below.
Pos. Description
1 Number of phases
2 Voltage [V]
3 Maximum current [A]
4 Rated current [A]
5 Power output [kW] / [hp]
6Single-phase pumps only:
Capacitor size [μF] and voltage [V]
5
English (GB)

2.2 Type key
CM, CME
Example
CME 10-8 A-R-A-E-A V B E X-X-X-X
Code Explanation
CME Code for type range
10 Rated flow rate at 50 Hz [m3/h]
8 Number of impellers
A Code for pump version
R Code for pump connection
A Code for materials in contact with pumped liquid
ECode for rubber parts in pump (excl. neck ring and
shaft seal)
A
V
B
E
Code for shaft seal:
• Shaft seal type designation
• Material of rotating seal face
• Material of stationary shaft seal part
• Material of secondary seal
X Code for supply voltage
X Code for motor information
X Code for mains plug
X Sensor designation
2.3 Key to codes
Code Description
Type range
CM Centrifugal Modular
CME CM with integrated frequency converter
Pump version
A Basic version
B Oversize motor (one flange size larger)
E Pumps with certificates and other approvals
HS High-pressure pump with high-speed MGE motor
I Altered pressure class
J Pump with a different maximum speed
M Magnet-driven pump
N CME pump with sensor (see code for "Sensor")
P Undersize motor (one flange size smaller)
T Oversize motor (two flange sizes larger)
V CME pump for Multi-E
X Special pump
Pipe connection
CTri-Clamp®
F DIN flange
G ANSI flange
J JIS flange
P PJE coupling
R Whitworth thread Rp (ISO 7/1)
S Internal NPT thread
Materials in contact with pumped liquid
A
Inlet and discharge parts EN-GJL-200
Pump shaft EN 1.4057/AISI 431
Impellers/chambers EN 1.4301/AISI 304
Sleeve EN 1.4401/AISI 316
G Pump shaft EN 1.4401/AISI 316
Code Description
Impellers/chambers EN 1.4401/AISI 316
Sleeve EN 1.4301/AISI 304
IPump shaft EN 1.4301/AISI 304
Impellers/chambers EN 1.4301/AISI 304
X Special version
Rubber parts in pump (excl. neck ring and shaft seal)
E EPDM (ethylene propylene)
K FFKM (perfluor)
V FKM (fluor)
Note that gaskets between chambers of cast-iron versions are
made of Tesnit BA-U.
Shaft seal type designation
A O-ring seal with fixed driver
Material of rotating seal face
Q Silicon carbide (SIC)
V Aluminium oxide (AI203)
Material of stationary shaft seal part
B Carbon, synthetic resin-impregnated
Q Silicon carbide (SIC)
Material of secondary seal
E EPDM (ethylene propylene)
K FFKM (perfluor)
V FKM (fluor)
Supply voltage
A 1 x 220 V, 60 Hz
B 1 x 115/230 V, 60 Hz
C 1 x 220-240 V, 50 Hz
D 1 x 127 V, 60 Hz
E 3 x 208-230/440-480 V, 60 Hz
F 3 x 220-240/380-415 V, 50 Hz
G 3 x 200/346 V, 50 Hz; 200-220/346-380 V, 60 Hz
H 3 x 575 V, 60 Hz
I 3 x 400 V, 50/60 Hz
J 3 x 380-415 V, 50 Hz; 440-480 V, 60 Hz
K 1 x 220-240 V, MGE motor
L 3 x 380-480 V, MGE motor
M 1 x 208-230 V, MLE motor
N 3 x 460-480 V, MLE motor
O3 x 220-240/380-415 V, 50 Hz
3 x 220-255/380-440 V, 60 Hz
Motor information
A Standard motor (IP55)
BPhase-insulated motor for use with frequency con-
verter
C IP54
D Pt100 in stator
E Angular contact bearing
F Motor heater
G Three-phase motor with overload protection
H Single-phase motor with no overload protection
6
English (GB)

Code Description
Mains plug
A Cable glands
B Harting plug
C With cable
The type key cannot be used for ordering, as not all com-
binations are possible.
7
English (GB)

3. Tightening torques and lubricants
Pos. Designation Quantity Dimensions Torque [Nm] Lubricant
2b Screw, CM 1, 3, 5 2 M8 x 40 16-18 THREAD-EZE
Hexagon socket head cap screw CM 10, 15, 25 2 M8 x 80 16-18 THREAD-EZE
11 O-ring 2 ∅18.5 x 2.0 - -
25 Plug 2 - 10-12 -
26
Staybolt, CM 1, 3, 5, cast iron 4 M6 12-14 -
Staybolt, CM 1, 3, 5, stainless steel 4 M8 12-14 -
Staybolt, CM 10, 15, 25, cast iron 4 M8 25-27 THREAD-EZE
Staybolt, CM 10, 15, 25, stainless steel 4 M8 20-22 -
28g Screw 4 M6 x 14 8-10 THREAD-EZE
31 O-ring, CM 1, 3, 5 1 ∅114.0 x 3.90 - Rocol 22
O-ring, CM 10, 15, 25 1 ∅153.2 x 4.70 - Rocol 22
67 Lock nut 1 M8 21-23 -
102 O-ring 1 ∅17.86 x 2.62 - V7140084
103 Seal faces 1 - - Silicone oil, 350 cSt,
food grade
107 O-ring 1 ∅11.5 x 3.18 - Rocol 22
152 Screw 2 M4 x 8 2.7 - 3.3 -
4 M5 x 12 3.5 - 4 -
155 Bearing cover plate 1 - - Rocol 22
157a
Gasket, MG 71, MG 80 1 ∅114.8 / 121.2 x 0.25 - -
Gasket, MG 90 2 ∅141.2 / 145.5 - -
Gasket, MG 100 - - - -
158a O-ring 1 ∅35.4 x 1.97 - Rocol 22
159
O-ring, MG 71, MG 80 1 ∅32 x 2
- Rocol 22
O-ring, MG 90, MG 100 1 ∅52 x 3.0
O-ring, MG 112, 132 1 ∅62 x 3.0
159a Seal ring 1 - - Castrol LMX grease
181
Screw, MG 71, MG 80 4 M6 x 16 5-8
THREAD-EZE
Staybolt, MG 90 4 M5 x 220
4.5 - 6
Staybolt, MG 90L 4 M5 x 260
Staybolt, MG 100 4 M5 x 270
Staybolt, MG 112 4 M6 x 288
THREAD-EZE, product number 00SV9997 (0.5 l).
Rocol 22, product number 00RM2924 (1 kg).
Castrol LMX grease, product number 00RM4311.
Silicone oil, 350 cSt, food grade 00SV0862 (1 l).
8
English (GB)

4. Service tools
A B C D
E F G H
I J K L
M N
4.1 Standard tools
Pos. Designation For pos. Further information Product number
A Screwdriver 103, 156 - SV0803
B Cross-head screwdriver 181 Ph2 x 100 SV0279
C Torx screwdriver J TX30 x 115 mm SV0335
D Ring/open-end spanner 64c 15 mm -
67 13 mm SV0055
E Hexagon key 26 5 mm -
6 mm SV0196
F Puller for bearing 153, 154 - -
G Plastic hammer 156 - SV0349
H Ratchet handle 156 - 96777072
I Hexagon head driver 26 M6 - 5 mm SV0296 M8 - 6 mm SV0297
181 M5 - 4 mm -
J Bits kit 28g, 152, 181 - SV2010
4.2 Torque tools
Pos. Designation For pos. Further information Product number
K Torque screwdriver J 1-6 Nm SV0438
L Ring insert tool N 13 mm - 9 x 12 mm SV0294
M Ratchet insert tool I 9 x 12 mm - 1/2" SV0295
N Torque wrench L, M 9 x 12 mm - 4-20 Nm SV2092
9 x12 mm - 20-100 Nm SV0269
9
English (GB)

5. Dismantling and assembly
5.1 General information
DANGER
Electric shock
Death or serious personal injury
‐Before starting any work on the product, make sure
that the power supply has been switched off and that it
cannot be accidentally switched on.
WARNING
Corrosive liquids
Death or serious personal injury
‐Wear personal protective equipment.
WARNING
Toxic liquids
Death or serious personal injury
‐Wear personal protective equipment.
WARNING
Hot liquid
Death or serious personal injury
‐The pumped liquid may be scalding hot and under
high pressure. Before any removal or dismantling of
the pump, the system must therefore be drained, or
the isolating valves on either side of the pump must be
closed.
CAUTION
Hot or cold liquid
Minor or moderate personal injury
‐Wear personal protective equipment.
CAUTION
Back injury
Minor or moderate personal injury
‐Use lifting equipment which is approved for the weight
of the product.
‐Use a lifting method suitable for the weight of the prod-
uct.
‐Wear personal protective equipment.
If it is necessary to dismantle the pump, either because it is choked
or damaged, please follow the instructions in the following sections.
Position numbers of parts (digits) refer to the section on Drawings;
position numbers of tools (letters) refer to the section on Service
tools.
Before dismantling the pump
• Disconnect the electricity supply to the motor.
• Close the isolating valves, if fitted, to avoid draining the system.
• Remove the electric cable in accordance with local regulations.
Before assembly
• Clean and check all parts.
• Replace defective parts by new parts.
• Order the necessary service kits.
• Gaskets and O-rings should always be replaced when the pump
is overhauled.
• See the section on replacement of impellers and spacing pipes
before replacing an impeller or spacing pipe.
During assembly
• Lubricate and tighten screws and nuts to correct torque. See the
section on tightening torques and lubricants.
Related information
3. Tightening torques and lubricants
4. Service tools
5.9 Replacement of impellers and spacing pipes
7.1 CM 1, 3, 5
7.2 CM 10, 15, 25
5.2 CM 1, 3, 5, cast iron
5.2.1 Dismantling
1. Remove staybolts (pos. 26).
2. Remove inlet part (pos. 6).
3. Remove gasket (pos. 139b) and chamber (pos. 4e).
4. Hold clamp (pos. 64c), and remove nut (pos. 67).
5. Remove lock washers (pos. 66) and clamp (pos. 64c).
6. Remove impeller (pos. 49).
7. Remove bearing ring (pos. 47a) and short spacing pipe (pos.
64a).
Step 7 applies only to pumps with eight stages.
8. Remove chamber for bearing (pos. 4a), gasket (pos. 139b),
impeller (pos. 49) and spacing pipe (pos. 64).
Step 8 applies only to pumps with eight stages.
9. Continue the dismantling until shaft seal (pos. 105).
10. Remove shaft seal (pos. 105). See the figure below.
TM044327
Exploded view of shaft seal
Dismantling of MG 71 and MG 80, see the section on dis-
mantling.
Dismantling of MG 90 and MG 100, see the section on
dismantling.
It is advisable always to replace wear rings (pos. 45) and
wear ring retainers (pos. 65). See the section on checking
and replacing impellers and chambers.
Related information
5.6.1 Dismantling
5.7.1 Dismantling
5.8 Checking and replacing impellers and chambers
10
English (GB)

5.2.2 Assembly
Assembly of MG 71 and MG 80, see the section on as-
sembly.
Assembly of MG 90 and MG 100, see the section on as-
sembly.
1. Fit O-ring (pos. 102) on the stationary shaft seal part. See the
figure below. For correct lubricant, see the section on tightening
torques and lubricants.
TM044322
Fitting the O-ring on the stationary shaft seal part
2. Press the stationary shaft seal part home.
Do not touch the seal face.
TM044436
Fitting the stationary shaft seal part (only SiC/SiC)
3. Fit the rotating shaft seal part (pos. 104) so that the seal face
touches the stationary part.
Do not touch the seal face.
4. Fit O-ring (pos. 107) into the rotating shaft seal part (pos. 104).
For correct lubricant, see the section on tightening torques and
lubricants.
5. Fit retainer (pos. 111) and stop ring (pos. 111a).
TM044325
Fitting the stop ring
6. Fit spring (pos. 108) and driver (pos. 112).
TM044326
Fitting the spring and driver
7. Fit impeller (pos. 49), spacing pipe (pos. 64), gasket (pos. 139b)
and chamber plate (pos. 4f).
8. Continue the assembly until chamber for bearing (pos. 4a).
Step 8 applies only to pumps with eight stages.
9. Fit chamber for bearing (pos. 4a), short spacing pipe (pos. 64a),
gasket (pos. 139b) and bearing ring (pos. 47a). See the section
on order of assembly for chambers and impellers.
Step 9 applies only to pumps with eight stages.
10. Fit impeller (pos. 49), clamp (pos. 64c), washers (pos. 66) and
nut (pos. 67).
TM021057
Correct fitting of washers
11. Hold clamp (pos. 64c), and tighten nut (pos. 67). See the
section on tightening torques and lubricants.
12. Fit chamber (pos. 4e) and gasket (pos. 139b).
13. Fit inlet part (pos. 6).
14. Fit and cross-tighten staybolts (pos. 26). See the section on
tightening torques and lubricants.
Related information
3. Tightening torques and lubricants
5.6.2 Assembly
5.7.2 Assembly
8.1 Key for CM 1, 3, 5
11
English (GB)

5.3 CM 1, 3, 5, stainless steel
5.3.1 Dismantling
1. Remove staybolts (pos. 26).
2. Remove clamping flange (pos. 6a) and sleeve (pos. 16).
3. Remove chamber (pos. 4e).
4. Hold clamp (pos. 64c), and remove nut (pos. 67).
5. Remove lock washers (pos. 66) and clamp (pos. 64c).
6. Remove impeller (pos. 49).
7. Remove bearing ring (pos. 47a) and short spacing pipe (pos.
64a).
Step 7 applies only to pumps with eight or more
stages.
8. Remove chamber for bearing (pos. 4a), impeller (pos. 49) and
spacing pipe (pos. 64).
Step 8 applies only to pumps with eight or more
stages.
9. Continue the dismantling until shaft seal (pos. 105).
10. Remove shaft seal (pos. 105).
TM044327
Exploded view of shaft seal
11. Remove O-ring (pos. 31) and cover plate (pos. 32).
Dismantling of MG 71 and MG 80, see the section on dis-
mantling.
Dismantling of MG 90 and MG 100, see the section on
dismantling.
It is advisable always to replace wear rings (pos. 45) and
wear ring retainers (pos. 65). See the section on checking
and replacing impellers and chambers.
Related information
5.6.1 Dismantling
5.7.1 Dismantling
5.8 Checking and replacing impellers and chambers
12
English (GB)

5.3.2 Assembly
Assembly of MG 71 and MG 80, see the section on as-
sembly. Assembly of MG 90 and MG 100, see the section
on assembly.
1. Fit cover plate (pos. 32) and O-ring (pos. 31). Lubricate the O-
ring. See the section on tightening torques and lubricants.
2. Fit O-ring (pos. 102) on the stationary shaft seal part. See the
section on tightening torques and lubricants.
TM044322
Fitting the O-ring on the stationary shaft seal part
3. Press the stationary shaft seal part home.
Do not touch the seal face.
TM044435
Fitting the stationary shaft seal part (only SiC/SiC)
4. Fit the rotating shaft seal part (pos. 104) so that the seal face
touches the stationary part.
Do not touch the seal face.
5. Fit O-ring (pos. 107) into the rotating shaft seal part (pos.
104). See the section on tightening torques and lubricants.
6. Fit retainer (pos. 111) and stop ring (pos. 111a).
TM044325
Fitting the stop ring
7. Fit spring (pos. 108) and driver (pos. 112).
TM044326
Fitting the spring and driver
8. Fit impeller (pos. 49), chamber with holes (pos. 4d) and spacing
pipe (pos. 64).
9. Fit impeller (pos. 49), chamber (pos. 4) and spacing pipe (pos.
64).
10. Fit impeller (pos. 49), chamber (pos. 4a), short spacing pipe
(pos. 64a) and bearing ring (pos. 47a). See the section on order
of assembly for chambers and impellers.
Step 10 applies only to pumps with eight or more
stages.
11. Fit impeller (pos. 49), clamp (pos. 64c), washers (pos. 66) and
nut (pos. 67).
TM021057
Correct fitting of washers
12. Hold clamp (pos. 64c), and tighten nut (pos. 67). See the
section on tightening torques and lubricants.
13. Fit chamber (pos. 4e), sleeve (pos. 16) and clamping flange
(pos. 6a).
Do not forget to fit the last chamber (pos. 4e), as it is
possible to assemble the pump without the last cham-
ber.
14. Make sure the holes on the chamber with holes (pos. 4d) are
facing the same direction as the outlet port of the sleeve (pos.
16) and the outlet port is positioned in the middle between the
holes. In the case of 3 and 9 o’clock variants, this rule must be
followed as well.
A = A
TM075504
Correct positioning of the chamber with holes (pos. 4d) and the
outlet port of the sleeve (pos. 16)
15. Fit and cross-tighten staybolts (pos. 26).
Related information
3. Tightening torques and lubricants
5.6.2 Assembly
5.7.2 Assembly
8.1 Key for CM 1, 3, 5
13
English (GB)

5.4 CM 10, 15, 25, cast iron
5.4.1 Dismantling
1. Remove staybolts (pos. 26).
2. Remove inlet part (pos. 6) and gasket (pos. 139b).
3. Hold clamp (pos. 64c), and remove nut (pos. 67).
4. Remove lock washers (pos. 66) and clamp (pos. 64c).
5. Remove impeller (pos. 49) and spacing pipe (pos. 64).
6. Remove chamber (pos. 4).
7. Continue the dismantling until shaft seal (pos. 105).
8. Remove shaft seal (pos. 105).
TM044327
Exploded view of shaft seal
9. Loosen and remove screws (pos. 2b) and discharge part (pos.
2).
Dismantling of MG 71 and MG 80, see the section on dis-
mantling.
Dismantling of MG 90, MG 100, MG 112 and MG 132, see
the section on dismantling.
It is advisable always to replace wear rings (pos. 45) and
wear ring retainers (pos. 65).
See the section on checking and replacing impellers and
chambers.
Related information
5.6.1 Dismantling
5.7.1 Dismantling
5.8 Checking and replacing impellers and chambers
5.4.2 Assembly
Assembly of MG 71 and MG 80, see the section on as-
sembly.
Assembly of MG 90, MG 100, MG 112 and MG 132, see
the section on assembly.
1. Fit discharge part (pos. 2).
2. Fit and tighten screws (pos. 2b). See the section on tightening
torques and lubricants.
3. Fit O-ring (pos. 102) on the stationary shaft seal part. See the
section on tightening torques and lubricants.
TM044322
Fitting the O-ring on the stationary shaft seal part
4. Press the stationary shaft seal part home.
Do not touch the seal face.
TM045051
Fitting the stationary shaft seal part (only SiC/SiC)
5. Fit the rotating shaft seal part (pos. 104) so that the seal face
touches the stationary part.
Do not touch the seal face.
6. Fit O-ring (pos. 107) into the rotating shaft seal part (pos.
104). See the section on tightening torques and lubricants.
7. Fit retainer (pos. 111) and stop ring (pos. 111a).
TM044325
Fitting the stop ring
14
English (GB)

8. Fit spring (pos. 108) and driver (pos. 112).
TM044326
Fitting the spring and driver
9. Fit short spacing pipe (pos. 64a), impeller (pos. 49), gasket
(pos. 139c) and chamber (pos. 4g).
10. Fit gasket (pos. 139b), spacing pipe (pos. 64), impeller (pos. 49)
and chamber (pos. 4).
11. Continue the assembly until clamp (pos. 64c). For correct fitting
of chambers and impellers, see the section on order of
assembly for chambers and impellers.
12. Fit impeller (pos. 49), clamp (pos. 64c), washers (pos. 66) and
nut (pos. 67).
TM021057
Correct fitting of washers
13. Hold clamp (pos. 64c), and tighten nut (pos. 67). See the
section on tightening torques and lubricants.
14. Fit gasket (pos. 139b).
15. Fit inlet part (pos. 6).
16. Fit and cross-tighten staybolts (pos. 26). See the section on
tightening torques and lubricants.
Related information
3. Tightening torques and lubricants
5.6.2 Assembly
5.7.2 Assembly
8.1 Key for CM 1, 3, 5
5.5 CM 10, 15, 25, stainless steel
5.5.1 Dismantling
1. Remove staybolts (pos. 26).
2. Remove clamping flange (pos. 6a) and sleeve (pos. 16).
3. Remove the chamber plate (pos. 4f).
4. Hold clamp (pos. 64c), and remove nut (pos. 67).
5. Remove lock washers (pos. 66) and clamp (pos. 64c).
6. Remove impeller (pos. 49).
7. Remove spacing pipe (pos. 64e), bearing ring (pos. 47a) and
chamber for bearing (pos. 4a).
Step 7 applies only to pumps with six or more stages.
8. Continue the dismantling until shaft seal (pos. 105).
9. Remove shaft seal (pos. 105).
TM044327
Exploded view of shaft seal
10. Remove O-ring (pos. 31) and cover plate (pos. 32).
Dismantling of MG 71 and MG 80, see the section on dis-
mantling.
Dismantling of MG 90, MG 100, MG 112 and MG 132, see
the section on dismantling.
It is advisable always to replace wear rings (pos. 45) and
wear ring retainers (pos. 65). See the section on checking
and replacing impellers and chambers.
Related information
5.6.1 Dismantling
5.7.1 Dismantling
5.8 Checking and replacing impellers and chambers
15
English (GB)

5.5.2 Assembly
Assembly of MG 71 and MG 80, see the section on as-
sembly.
Assembly of MG 90, MG 100, MG 112 and MG 132, see
the section on assembly.
1. Fit cover plate (pos. 32) and O-ring (pos. 31). Lubricate the O-
ring. See the section on tightening torques and lubricants.
2. Fit O-ring (pos. 102) on the stationary shaft seal part. For
correct lubricant, see the section on tightening torques and
lubricants.
TM044322
Fitting the O-ring on the stationary shaft seal part
3. Press the stationary shaft seal part home.
Do not touch the seal face.
TM044435
Fitting the stationary shaft seal part (only SiC/SiC)
4. Fit the rotating shaft seal part (pos. 104) so that the seal face
touches the stationary part.
Do not touch the seal face.
5. Fit O-ring (pos. 107) into the rotating shaft seal part (pos. 104).
For correct lubricant, see the section on tightening torques and
lubricants.
6. Fit retainer (pos. 111) and stop ring (pos. 111a).
TM044325
Fitting the stop ring
7. Fit spring (pos. 108) and driver (pos. 112).
TM044326
Fitting the spring and driver
8. Fit short spacing pipe (pos. 64a), chamber with holes (pos. 4d)
and impeller (pos. 49).
9. Continue the assembly until clamp (pos. 64c). For correct fitting
of chambers and impellers, see the section on order of
assembly for chambers and impellers.
10. Fit clamp (pos. 64c), washers (pos. 66) and nut (pos. 67).
TM021057
Correct fitting of washers
11. Hold clamp (pos. 64c), and tighten nut (pos. 67). See the
section on tightening torques and lubricants.
12. Fit the chamber plate (pos. 4f).
Do not forget to fit the chamber plate (pos. 4f), as it is
possible to assemble the pump without the last cham-
ber.
13. Fit sleeve (pos. 16) and clamping flange (pos. 6a).
14. Make sure the holes on the chamber with holes (pos. 4d) are
facing the same direction as the outlet port of the sleeve (pos.
16) and the outlet port is positioned in the middle between the
holes. In the case of 3 and 9 o’clock variants, this rule must be
followed as well.
A = A
TM075503
Correct positioning of the chamber with holes (pos. 4d) and the
outlet port of the sleeve (pos. 16)
15. Fit and cross-tighten staybolts (pos. 26).
Related information
3. Tightening torques and lubricants
5.6.2 Assembly
5.7.2 Assembly
8.1 Key for CM 1, 3, 5
16
English (GB)

5.6 MG 71 and MG 80 motors
5.6.1 Dismantling
1. Remove screws (pos. 152).
2. Remove fan cover (pos. 151).
3. Remove fan (pos. 156) and seal ring (pos. 159a).
4. Remove screws (pos. 181).
5. Remove motor flange (pos. 156b) and gasket (pos. 157a).
6. Remove diverting disc (pos. 79), O-ring (pos. 158a) and bearing
cover plate (pos. 155).
7. Pull shaft (pos. 51) out of stator housing (pos. 150).
8. Pull bearing (pos. 153) off shaft (pos. 51).
9. Remove O-ring (pos. 159) and spring (pos. 158).
10. Pull bearing (pos. 154) off shaft (pos. 51).
5.6.2 Assembly
1. Push bearing (pos. 154) onto shaft (pos. 51).
2. Fit spring (pos. 158) and O-ring (pos. 159).
TM044441
Correct fitting of spring and O-ring
3. Push bearing (pos. 153) onto shaft (pos. 51).
4. Fit shaft (pos. 51) into stator housing (pos. 150).
5. Fit bearing cover plate (pos. 155), O-ring (pos. 158a) and
diverting disc (pos. 79). Lubricate the surface of the cover plate
(pos. 155) turning against the bearing. Lubricate the O-ring (pos.
158a). For correct lubricant, see the section on tightening
torques and lubricants.
6. Fit gasket (pos. 157a) and motor flange (pos. 156b).
7. Fit and cross-tighten screws (pos. 181). See the section on
tightening torques and lubricants.
8. Fit and lubricate the seal ring (pos. 159a). For correct
lubricant, see the section on tightening torques and lubricants.
9. Fit the fan (pos. 156).
10. Fit fan cover (pos. 151).
11. Fit and tighten screws (pos. 152).
Related information
3. Tightening torques and lubricants
5.7 MG 90, MG 100, MG 112 and MG 132 motors
5.7.1 Dismantling
1. Only cast iron pumps: Remove screws (pos. 2b).
2. Only cast iron pumps: Remove discharge part (pos. 2).
3. Remove screws (pos. 152).
4. Remove fan cover (pos. 151).
5. Remove fan (pos. 156) and seal ring (pos. 159a).
6. Remove staybolts (pos. 181).
7. Remove motor flange (pos. 156b), gasket (pos. 157a) and
bearing cover (pos. 156a).
8. Remove diverting disc (pos. 79), O-ring (pos. 158a) and bearing
cover plate (pos. 155).
9. Pull shaft (pos. 51) out of stator housing (pos. 150).
10. Pull bearing (pos. 153) off shaft (pos. 51).
11. Remove O-ring (pos. 159) and spring (pos. 158).
12. Pull bearing (pos. 154) off shaft (pos. 51).
5.7.2 Assembly
1. Push bearing (pos. 154) onto shaft (pos. 51).
2. Fit spring (pos. 158) and O-ring (pos. 159).
TM044441
Correct fitting of spring and O-ring
3. Push bearing (pos. 153) onto shaft (pos. 51).
4. Fit shaft (pos. 51) into stator housing (pos. 150).
5. Fit bearing cover plate (pos. 155), O-ring (pos. 158a) and
diverting disc (pos. 79). Lubricate the surface of the cover plate
(pos. 155) turning against the bearing. Lubricate the O-ring (pos.
158a). For correct lubricant, see the section on tightening
torques and lubricants.
6. Fit bearing cover (pos. 156a), gasket (pos. 157a) and motor
flange (pos. 156b).
7. Fit and cross-tighten staybolts (pos. 181). See the section on
tightening torques and lubricants.
8. Fit and lubricate the seal ring (pos. 159a). For correct see the
section on tightening torques and lubricants.
9. Fit the fan (pos. 156).
10. Fit fan cover (pos. 151).
11. Fit and tighten screws (pos. 152). See the section on tightening
torques and lubricants.
12. Only cast iron pumps: Fit discharge part (pos. 2).
13. Only cast iron pumps: Fit and tighten screws (pos. 2b).
Related information
3. Tightening torques and lubricants
17
English (GB)

5.8 Checking and replacing impellers and chambers
Check Replace
Impeller Wear ring/wear ring retainer
• Check whether it is necessary to replace the impeller due to fric-
tion between wear ring and impeller skirt. If wear has caused a
noticeable (use a finger nail) groove in the impeller skirt, the im-
peller should be replaced.
It is advisable always to replace wear rings (pos. 45) and wear
ring retainers (pos. 65) when the chamber stack is dismantled.
1. Prise the wear ring retainer (pos. 65) up and free of the chamber
using a screwdriver.
2. Remove wear ring (pos. 45).
3. Fit a new wear ring in the chamber. See the figure below.
4. Press a new wear ring retainer on the wear ring and into the cham-
ber.
It must be possible to move the wear ring freely (sideways) between
the retainer and the chamber.
Bearing ring
• Check whether there is a visible and noticeable (use a finger nail)
edge on the rotating bearing ring.
• Replace both bearing rings (pos. 47a) and chamber for bearing
(pos. 4a).
TM021182
Correct fitting of wear ring
5.9 Replacement of impellers and spacing pipes
Replace all impellers and spacing pipes. If new impellers
or spacing pipes are installed in combination with old im-
pellers and spacing pipes, the pump will not run optimally
and it may malfunction.
Based on production date, different impellers and spacing pipes
have been designed for CM, CME pumps. New impellers and
spacing pipes are therefore not interchangeable with old impellers
and spacing pipes.
Therefore, Grundfos offers impellers and spacing pipes as complete
service kits, including the specific quantity and type of impellers and
spacing pipes for all CM, CME pump models.
18
English (GB)

6. Fault finding
DANGER
Electric shock
Death or serious personal injury
‐Before starting any work on the product, make sure that the power supply has been switched off and that it cannot be accidental-
ly switched on.
WARNING
Corrosive liquids
Death or serious personal injury
‐Wear personal protective equipment.
WARNING
Toxic liquids
Death or serious personal injury
‐Wear personal protective equipment.
WARNING
Hot liquid
Death or serious personal injury
‐The pumped liquid may be scalding hot and under high pressure. Before any removal or dismantling of the pump, the system
must therefore be drained, or the isolating valves on either side of the pump must be closed.
CAUTION
Hot or cold liquid
Minor or moderate personal injury
‐Wear personal protective equipment.
CAUTION
Back injury
Minor or moderate personal injury
‐Use lifting equipment which is approved for the weight of the product.
‐Use a lifting method suitable for the weight of the product.
‐Wear personal protective equipment.
6.1 The pump does not run.
Cause Remedy
Supply failure. • Switch on the switch.
• Check cables and cable connections for defects and loose
connections.
Fuses are blown. • Check cables and cable connections for defects, and replace the
fuses.
Motor protection tripped. • Check cables and cable connections for defects and loose
connections.
• Replace the contacts of the motor-protective circuit breaker, the
magnet coil or the entire motor-protective circuit breaker.
• Check cables and cable connections for defects, and replace the
fuses.
• Repair or replace the motor.
• Switch off the electricity supply, and clean or repair the pump.
• Set the motor-protective circuit breaker according to the rated
current of the motor (I1/1). See nameplate.
Control-current circuit defective. • Repair or replace the control-current circuit.
6.2 Motor-protective circuit breaker has tripped (trips out immediately when supply is switched on).
Cause Remedy
Fuses are blown. • Check cables and cable connections for defects, and replace the
fuses.
Contacts of the motor-protective circuit breaker or magnet coil
defective.
• Replace the contacts of the motor-protective circuit breaker, the
magnet coil or the entire motor-protective circuit breaker.
Cable connection is loose or faulty. • Check cables and cable connections for defects, and replace the
fuses.
19
English (GB)

Cause Remedy
Motor winding is defective. • Repair or replace the motor.
The pump is mechanically blocked. • Switch off the electricity supply, and clean or repair the pump.
The setting of the motor-protective circuit breaker is too low. • Set the motor-protective circuit breaker according to the rated
current of the motor (I1/1). See nameplate.
6.3 The motor-protective circuit breaker trips out occasionally.
Cause Remedy
The setting of the motor-protective circuit breaker is too low. • Set the motor-protective circuit breaker according to the rated
current of the motor (I1/1). See nameplate.
Periodic supply failure. • Check cables and cable connections for defects, and replace the
fuses.
Periodically low voltage. • Check cables and cable connections for defects and loose
connections.
• Check that the supply cable of the pump is correctly sized.
20
English (GB)