Grundfos MQ 3-45 Service Instructions

28.04.2003
GB
10 / 24
3.5 Replacing the motor unit
3.5.1 Removing the motor unit
1. Remove the shaft seal, see 3.2.1
Removing the shaft seal.
2. Remove the electronic unit, flow sensor and pressure switch, see 3.4.1
Removing the electronic unit, flow
sensor and pressure switch.
3. Remove the pressure tank, see 3.3.1
Removing the pressure tank.
4. Slacken and remove the screws pos. 152 and washers pos. 152a, -b and -c.
5. Remove the end cover pos. 51.
6. Remove the screw for the earth lead pos. 173 on the motor unit pos. 50.
7. Pull the leads to the motor unit out of the terminal box.
8. Press the motor unit pos. 150 out of the motor housing pos. 180.
9. Remove the screws pos. 26, washers pos. 27 and intermediate part pos. 2.
10. Remove the retainer pos. 40a and the O-rings pos. 40.
3.5.2 Fitting the motor unit
1. Lubricate the O-rings pos. 40 and fit the rings and the retainer pos. 40.
2. Lubricate the O-ring pos. pos. 37a and fit it on the motor housing pos. 180.
3. Fit the motor housing pos. 180 to the intermediate part pos. 2.
4. Fit the screws pos. 26 and the washers pos. 27 and tighten diagonally.
5. Lubricate the recess of the O-ring pos. 53 in the motor housing pos. 180.
6. Roll the O-ring pos. 53 on the motor unit pos. 150 and lubricate it.
7. Fit the motor unit in the motor housing pos. 180.
8. Pull the leads from the motor unit into the terminal box.
9. Pull the earth lead into the terminal box. The earth lead lug must not touch the other leads.
10. Fit the earth lead to the motor unit and tighten the screw pos. 173.
11. Lubricate and fit the O-ring pos. 52 to the end cover pos. 51.
12. Fit the end cover pos. 51. The leads from the motor must fit into the slot.
13. Fit the screws pos. 152 and washers pos. 152a, -b and -c and tighten.
14. Fit the pressure tank, see 3.3.2
Fitting the pressure tank.
15. Fit the electronic unit, flow sensor and pressure switch, see 3.4.2
Fitting the electronic unit, flow sensor
and pressure switch.
16. Fit the shaft seal, see 3.2.2
Fitting the shaft seal.

Grundfos MQ 3-45 Specifications

General

Power consumption	1000 W
Maximum head	45 m
Maximum flow rate	3 m³/h
Protection class	IP54
Weight	13 kg
Maximum liquid temperature	35 °C
Maximum operating pressure	7.5 bar
Pumped liquid	Clean water
Liquid temperature range	0 - 35 °C
Maximum ambient temperature	45 °C
Supply voltage	220-240 V
Rated power - P2	0.75 kW
Mains frequency	50/60 Hz
Rated current	4.5 A
Enclosure class	IP54
Inlet connection	1 inch
Outlet connection	1 inch
Power supply	220-240 V, 50/60 Hz
Pump type	Centrifugal
Built-in pressure tank	Yes
Approvals	CE
Material	Stainless steel