Grundfos NB Series Operating instructions

Service instructions
NB/NBG
96778604 1111 GB 1 / 12
1. Identification .................................................................................................................................... 2
1.1 Nameplate ...........................................................................................................................................................2
1.2 Type key..............................................................................................................................................................3
1.3 Handling...............................................................................................................................................................4
2. Dismantling and assembly ............................................................................................................. 5
2.1 General information.............................................................................................................................................5
2.2 Dismantling..........................................................................................................................................................5
2.3 Replacing the wear rings.....................................................................................................................................6
2.4 Assembling the pump..........................................................................................................................................6
3. Fault finding..................................................................................................................................... 7
4. Service tools .................................................................................................................................... 9
4.1 Special tools ........................................................................................................................................................9
4.2 Standard tools....................................................................................................................................................10
4.3 Torque tools.......................................................................................................................................................10
5. Tightening torques and lubricants............................................................................................... 11
5.1 Lubrication.........................................................................................................................................................11
6. Exploded view................................................................................................................................ 12

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1. Identification
1.1 Nameplate
Fig. 1 Example of nameplate for NB
The example shows an NB 80-200 with 196 mm impeller, made of cast iron, with BAQE shaft seal and a 4-pole motor.
Fig. 2 Example of nameplate for NBG
The example shows an NBG 125-80-200 with 196 mm impeller, made of cast iron, with BAQE shaft seal and a 4-pole
motor.
TM03 4243 1906TM03 3984 1406
Pos. Description
1 Type designation
2 Model
3 Rated flow rate, 50 Hz
4 Max. pressure/temperature
5 Place of production
6 Speed, 50 Hz
7 Head against closed valve, 50 Hz
bar/°CMAX
m /h
3H
Q
p/t
mnmin -1
Model
96145329
Type
NB 80-200/196 A-F-A-BAQE
B 96125133 P2 0612 0001
91.2 10.8 1445
16/120
Made in Hungary
1
2
36
4
57
bar/°C MAX
m /h
3
H
Q
p/t
mnmin
-1
Model
96145329
Type
NBG 125-80-200/196 A-F-A-BAQE
A 96125133 P2 0612 0001
91.2 10.8 1445
16/120
Made in Hungary
1
2
36
4
57

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12
1.2 Type key
* Examples of combined pump version codes:
AE: Basic version with certificate or test report.
BD: With oversize motor and pump housing with feet.
CE: Without motor and with certificate and test report.
NB NBG
NB 32 -125 .1 /142 A -F -A -BAQE NBG 50 -32 -125 .1 /142 A -F -A -BAQE
Type range
NB
NBE
Type range
NBG
NBGE
Nominal diameter of
discharge port (DN)
Nominal diameter of
suction port (DN)
Nominal diameter of discharge
port (DN)
Nominal impeller diameter [mm] Nominal impeller diameter [mm]
Reduced performance = .1 Reduced performance = .1
Actual impeller diameter [mm] Actual impeller diameter [mm]
Code for pump version (the codes can be
combined*)
A: Basic version
B: Oversize or double-oversize motor
C: Without motor
D: Pump housing with feet
E: With ATEX approval, certificate or test
report
X: Special version
Code for pump version (the codes can be
combined*)
A: Basic version
B: Oversize or double-oversize motor
C: Without motor
D: Pump housing with feet
E: With ATEX approval, certificate or test report
X: Special version
Code for pipe connection:
F: DIN flange (EN 1092-2)
Code for pipe connection:
F: DIN flange (EN 1092-2)
E: Table E flange
Code for materials:
A: Cast iron EN-GJL-250 pump housing,
EN-GJL-250 impeller, bronze wear ring
B: Cast iron EN-GJL-250 pump housing, bronze
impeller CuSn10, bronze wear ring
S: Cast iron EN-GJL-250 pump housing, 1.4408
impeller, bronze wear ring
N: 1.4408 pump housing and impeller, carbon-
graphite-filled PTFE wear ring
R: 1.4517 pump housing and impeller, carbon-
graphite-filled PTFE wear ring
P: 1.4408 pump housing, 1.4517 impeller, carbon-
graphite-filled PTFE wear ring
K: 1.4408 pump housing and impeller, 1.4517 wear
ring
L: 1.4517 pump housing, impeller and wear ring
M: 1.4408 pump housing, 1.4517 impeller and wear
ring
X: Special version
Code for materials:
A: Cast iron EN-GJL-250 pump housing, EN-GJL-250
impeller, bronze wear ring
B: Cast iron EN-GJL-250 pump housing, bronze impeller
CuSn10, bronze wear ring
S: Cast iron EN-GJL-250 pump housing, 1.4408 impeller,
bronze wear ring
N: 1.4408 pump housing and impeller, carbon-graphite-
filled PTFE wear ring
R: 1.4517 pump housing and impeller, carbon-graphite-
filled PTFE wear ring
P: 1.4408 pump housing, 1.4517 impeller, carbon-
graphite-filled PTFE wear ring
K: 1.4408 pump housing and impeller, 1.4517 wear ring
L: 1.4517 pump housing, impeller and wear ring
M: 1.4408 pump housing, 1.4517 impeller and wear ring
X: Special version
Code for shaft seal and rubber pump parts Code for shaft seal and rubber pump parts

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Mechanical shaft seal
* Maximum 60 °C
1.3 Handling
Pumps fitted with motors should be lifted by means of nylon straps and shackles, if required. See fig. 3.
Shaft seal diameter [mm] 28, 38 48 55 60
Code Temperature range Max. pressure [bar]
Rubber bellows seal, metal-impregnated carbon/silicon carbide,
EPDM BAQE 0 °C to +120 °C 16 16 16 16
Rubber bellows seal, metal-impregnated carbon/silicon carbide,
FKM BAQV 0 °C to +90 °C 16 16 16 16
Rubber bellows seal, silicon carbide/silicon carbide, EPDM BQQE 0 °C to +90 °C 16 16 16 16
Rubber bellows seal, silicon carbide/silicon carbide, FKM BQQV 0 °C to +90 °C 16 16 16 16
Bellows seal, type B, with reduced seal faces, silicon carbide/
silicon carbide, EPDM GQQE –25 °C to +90 °C 16 16* 16* 16*
Bellows seal, type B, with reduced seal faces, silicon carbide/
silicon carbide, FKM GQQV –20 °C to +90 °C 16 16* 16* 16*
O-ring seal with fixed seal driver, silicon carbide/silicon carbide,
EPDM AQQE 0 °C to +90 °C 25 25 16 16
O-ring seal with fixed seal driver, silicon carbide/silicon carbide,
FKM AQQV 0 °C to +90 °C 25 25 16 16
O-ring seal with fixed seal driver, silicon carbide/metal-
impregnated carbon, EPDM AQAE 0 °C to +120 °C 25 25 25 25
O-ring seal with fixed seal driver, silicon carbide/metal-
impregnated carbon, FKM AQAV 0 °C to +90 °C 25 25 25 25
Rubber bellows seal, silicon carbide/resin-impregnated carbon,
EPDM BQBE 0 °C to +140 °C 16 - - -
O-ring seal, balanced, metal-impregnated carbon/silicon carbide,
FXM DAQF 0 °C to +140 °C 25 25 25 25
Rubber bellows seal, resin-impregnated carbon/silicon carbide,
EPDM BBQE 0 °C to +120 °C 16 16 16 16
Warning
Pump motors as from 4 kW are supplied with lifting eyes which must not be used for lifting the
entire pump unit. See fig. 4.
TM03 3973 1306 TM03 3972 1306
Fig. 3 Correct lifting of pump Fig. 4 Incorrect lifting of pump

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2. Dismantling and assembly
2.1 General information
Follow these instructions if it is necessary to dismantle the pump, either because it is clogged or damaged.
Position numbers of parts (digits) refer to section 6. Exploded view; position numbers of service tools (letters) refer to
section 4. Service tools.
Before dismantling
• 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
• Order the necessary service kits.
• Clean and check all parts.
• Replace defective parts by new parts.
• Always replace gaskets and O-rings when the pump is serviced.
During assembly
• Lubricate and tighten screws and nuts to correct torque. See section 5. Tightening torques and lubricants.
2.2 Dismantling
1. Remove the nuts (pos. 36) from the pump housing (pos. 6).
2. Remove the pump housing. It may be necessary to use a plastic hammer (pos. I) or a pinch bar (pos. F) for
separating the pump housing from the motor stool (pos. 1a) or cover (pos. 77).
3. Remove the O-ring (pos. 72a) from the motor stool/cover.
4. Hold the impeller with a strap wrench (pos. D), and slacken the impeller nut (pos. 67). Remove the impeller
nut, spring washer (pos. 66a) and washer (pos. 66) from the shaft.
5. Remove the impeller (pos. 49) using a puller.
6. Remove the key (pos. 11) from the shaft (pos. 51).
7. Remove the spacer rings, if any, between impeller and shaft seal (pos. 105).
8. Shaft seal, types MG13 and HJ92:
• Pull off the rotating shaft seal part using two screwdrivers.
Shaft seal, type M7N:
• First, pull off the spring retainer using two screwdrivers. Next, remove the seal ring with O-ring using two
screwdrivers.
9. Pump with separate motor stool (pos. 1a) and clamped cover (pos. 77):
• Remove the cover.
Pump with separate motor stool (pos. 1a) and screw-fixed cover (pos. 77):
• Remove the screws holding cover and motor stool together, and pull off the cover.
Pump with integrated motor stool/cover (pos. 2):
• Remove the coupling guards (pos. 7) and the screws/nuts holding the motor stool (pos. 28 and 36a) and motor
together. Remove the motor stool (pos. 2). It may be necessary to loosen the motor stool from the motor with a
plastic hammer.
10.Remove the stationary shaft seal part by pushing it from the back.
11. Slacken the screws (pos. 9) fixing the pump shaft (pos. 51) on the motor shaft.
12.Remove the pump shaft. It may be necessary to loosen it with a pinch bar or similar tool.

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2.3 Replacing the wear rings
Pump with bronze wear rings
1. Insert the hook of the puller (pos. C) under the wear ring (pos. 45 or 45b).
2. Knock the impact block against the puller end stop. Move the puller to another position under the wear ring.
3. Knock the new wear ring home using a piece of wood as a buffer.
4. Repeat steps 1 to 3 for the second wear ring of the pump.
Pump with stainless steel wear rings
1. Unscrew the screws (pos. 24 and 24b) of both wear rings (pos. 45 and 45b), and remove the wear rings.
2. Fit new wear rings, and tighten the screws to the correct torque.
Pump with stainless steel/carbon-graphite-filled wear rings
1. Unscrew the screws (pos. 24 and 24b) of both wear ring retainers (pos. 65 and 65b), and remove the wear
ring retainers.
2. Push the carbon-graphite-filled wear rings (pos. 45 and 45b) out of the wear ring retainers.
3. Fit new carbon-graphite-filled wear rings in the wear ring retainers.
4. Fit the wear rings/wear ring retainers, and tighten the screws to the correct torque.
2.4 Assembling the pump
1. Lubricate the motor shaft with O-ring grease.
2. Push the pump shaft (pos. 51) home on the motor shaft. Make sure that the pump shaft does not move when
you release it.
3. Apply a drop of Loctite 243 to the set screws (pos. 9), and tighten them into the pump shaft to the correct
torque.
4. Fit the motor stool (pos. 1a or 2) on the motor.
5. Fit the screws/nuts (pos. 28 and 36a) on the motor stool, and tighten them to the correct torque.
6. Fit the mounting bush (pos. A) on the pump shaft.
7. Pump with separate motor stool (pos. 1a) and clamped cover (pos. 77):
• Fit the cover to the motor stool.
Pump with separate motor stool (pos. 1a) and screw-fixed cover (pos. 77):
• Fit the cover to the motor stool, and tighten it to the correct torque.
8. Spray soapy water on the pump shaft and the mounting bush.
9. Fit the stationary shaft seal part (pos. 105) on the shaft. Do not touch the seal face with your fingers.
10.Press the stationary shaft seal part home using a punch of soft material (pos. B).
11.Shaft seal, types HJ92 and M7N:
• Remove the screws, if any, from the rotating shaft seal part, and discard them.
12.Spray soapy water on the rotating shaft seal part.
13.Press the rotating shaft seal part home using a punch of soft material (pos. B).
14.Fit spacer rings, if required, between shaft seal and impeller on the pump shaft.
15.Remove the mounting bush (pos. A) from the pump shaft.
16.Fit the key (pos. 11) and the impeller (pos. 49) on the shaft.
17.Fit the washer (pos. 66), spring washer (pos. 66a) and impeller nut (pos. 67).
18.Hold the impeller with a strap wrench, and tighten the impeller nut to the correct torque.
19.Fit the O-ring (pos. 72a) on the cover, and lubricate it.
20.Fit the pump housing (pos. 6).
21.Fasten the cover/motor stool on the pump housing by cross-tightening the nuts (pos. 36) to the correct torque.
22.Check that the pump shaft can rotate freely.
23.Fit the coupling guards (pos. 7), and tighten the screws to the correct torque.

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3. Fault finding
Warning
Before removing the terminal box cover and before any dismantling of the pump, make sure
that the electricity supply has been switched off. It must be ensured that it cannot be
accidentally switched on.
Fault Cause Remedy
1. The pump delivers no
or too little liquid. a) Wrong electrical connection (2 phases). Check the electrical connection, and remedy, if necessary.
b) Wrong direction of rotation. Interchange two phases of the mains supply.
c) Air in suction pipe. Vent the suction pipe or the pump, and replenish.
d) Counter-pressure too high. Set the duty point in accordance with the data
sheet. Check the system for impurities.
e) Inlet pressure too low. Increase the liquid level on the suction side.
Open the isolating valve in the suction pipe.
See the installation and operating instructions.
f) Suction pipe blocked, or impurities in
impeller. Clean the pump.
g) Pump draws in air due to defective seal. Check the pipeline seals, pump housing gaskets
and shaft seals, and replace, if necessary.
h) Pump draws in air due to low liquid level. Increase the liquid level on the suction side, and
keep it as constant as possible.
2. The motor-protective
circuit breaker has
tripped because the
motor is overloaded.
a) Pump blocked by impurities. Clean the pump.
b) Pump running above the rated duty point. Set the duty point in accordance with the data
sheet.
c) Density or viscosity of the liquid is higher
than specified when ordering. If less flow is sufficient, reduce the flow on the discharge side. Or fit a more powerful motor.
d) Motor starter overload setting is incorrect. Check the setting of the motor-protective circuit
breaker, and replace, if necessary.
e) The motor runs on two phases. Check the electrical connection. Replace the fuse,
if defective.
3. Pump makes too
much noise.
Pump runs unevenly
and vibrates.
a) Inlet pressure too low (cavitation). Increase the liquid level on the suction side.
Open the isolating valve in the suction pipe.
See the installation and operating instructions.
b) Air in suction pipe or pump. Vent the suction pipe or the pump, and replenish.
c) Counter-pressure is lower than specified. Set the duty point in accordance with the data
sheet.
d) Pump draws in air due to low liquid level. Increase the liquid level on the suction side, and
keep it as constant as possible.
e) Impeller out of balance (clogged impeller
blades). Clean and check the impeller.
f) Inner parts worn. Replace defective parts.
g) Pump stressed by the pipework
(thus causing starting noise). Mount the pump so that it is not stressed. Support the pipes.
h) Defective bearings. Replace the bearings.
i) Defective motor fan. Replace the fan.
j) Foreign bodies in the pump. Clean the pump.
k) Frequency converter operation. See the installation and operating instructions.
4. Leakage in pump or at
connections.
Leakage in
mechanical shaft seal.
a) Pump stressed by the pipework
(thus causing leaks in the pump or at
connections).
Mount the pump so that it is not stressed.
Support the pipes.
b) Pump housing gaskets and gaskets at
connections defective. Replace pump housing gaskets or gaskets at connections.
c) Mechanical shaft seal dirty or stuck
together. Check and clean the mechanical shaft seal.
d) Mechanical shaft seal defective. Replace the mechanical shaft seal.
e) Shaft surface defective. Replace the shaft.

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5. Too high temperature
in pump or motor. a) Air in suction pipe or pump. Vent the suction pipe or the pump, and replenish.
b) Inlet pressure too low. Increase the liquid level on the suction side.
Open the isolating valve in the suction pipe.
See the installation and operating instructions.
c) Bearings lubricated with too little, too much
or unsuitable lubricant. Replenish, reduce or replace lubricant.
d) Axial pressure too high. Check the relief holes of the impeller and the lock
rings on the suction side.
e) Motor-protective circuit breaker is
defective, or setting is incorrect. Check the setting of the motor-protective circuit breaker, and replace, if necessary.
f) The motor is overloaded. Reduce the flow rate.
Fault Cause Remedy

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4. Service tools
4.1 Special tools
ABCD
EFGH
IJKL
MNOP
QR
Pos. Description For pos. Further information Part number
AProtective sleeve 105
d28 V7216304
d38 V7216305
d48 70007165
d55 70007166
d60 70007167
BPunch for shaft seal 105
d28 V7216306
d38 V7216307
d48 70007172
d55 70007173
d60 70007174
CPuller for wear ring 45, 45b 96824962

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4.2 Standard tools
4.3 Torque tools
Pos. Description For pos. Further information Part number
DStrap wrench 49 00SV0853
EPuller 49
FPinch bar 51 SV5201
GRing/open-end spanner 36, 36a, 67
17 mm
19 mm
22 mm
24 mm
30 mm
36 mm
SV0056
SV0063
00SV0186
SV0122
SV0073
HPolygrip pliers 11 SV0150
IPlastic hammer 2, 77 SV0349
JScrewdriver 105
KCross-recess screwdriver 7a
LHexagon key 9, 9a
2.5 mm
3 mm
4 mm
6 mm
10 mm
SV0277
SV0278
SV0196
SV0033
MHexagon socket 36, 36a, 67
13 mm
17 mm
19 mm
22 mm
24 mm
27 mm
30 mm
36 mm
41 mm
50 mm
SV0413
SV0417
SV0419
SV0422
SV0424
SV0427
NBits kit 7a, 9, 9a SV2010
ORatchet handle M96777072
Pos. Description For pos. Further information Part number
PTorque screwdriver N1-6 Nm SV0438
QTorque wrench Q9 x12 mm - 4-20 Nm 9 x12 mm - 20-100 Nm
14 x18 mm - 40-200 Nm
SV2092
SV0269
SV0400
RRatchet insert tool M9 x12 mm - 1/2"
14 x 18 mm SV0295 SV0401