Grundfos MQ 3-45 Service Instructions

28.04.2003
GB
11 / 24
4. Operation
4.1 Priming
Before initial start-up, pour approx. 5 litres of water into the pump through the priming port, see the installa-
tion and operating instructions. When started, the pump will start to evacuate the air contained in the system.
Once it starts to deliver water, the pump will change over to normal operation (start/stop).
If no water is delivered within 5 minutes after start-up, the pump will stop automatically as protection
against dry running, and alarm will be indicated.
4.2 Start
The pump starts when
• the consumption is higher than 1.2 l/min or
• the pressure is lower than 2 bar.
4.3 Stop
The pump stops when
• the consumption is lower than 1.2 l/min.
4.4 Alarm
The pump stops in case of
• dry running (if the pressure falls below 2 bar and the consumption below 1.2 l/min, an alarm will be given
after 60 seconds)
• overtemperature (thermal switch in motor)
• overloaded motor (thermal switch in motor)
• seized-up motor/pump (thermal switch in motor).
4.5 Auto-reset
If activated, the auto-reset function will cause the pump to restart automatically every 30 minutes for 24
hours in case of any type of fault. After this period, if the fault has not disappeared, the pump will remain in
the alarm condition and can only be reset manually, see below.
4.6 Manual reset
The pump can be reset manually by
• pressing the on/off button twice or
• interrupting the supply voltage briefly.

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