GRUNDFOS DATA BOOKLET Grundfos ALPHA1 Circulator pumps 50/60 Hz

Pumped liquids Control of heating systems Advantages of pump control Type key Performance range Product introduction Stainless-steel versions N Sectional drawing Material specification Motor and control box Unique air vent system Guide to performance curves Energy labelling Curve conditions Installation Electrical data Startup Liquid temperature System pressure Inlet pressure Setting the pump Change of pump performance Product range Further product information WebCAPS WinCAPS GO CAPS ALPHA1 (N), Germany ALPHA1 (N), Austria and Switzerland ALPHA1 (N), international Union and valve kits Insulating...

Grundfos ALPHA1 is a complete range of circulator pumps with the following features: • integrated differential-pressure control enabling adjustment of pump performance to the actual system requirement • motor based on permanent-magnet/compact-rotor technology. The pumps are energy-optimised and comply with the requirements of the EuP directive. Product introduction 1. Product introduction Energy savings High-efficient permanent-magnet motors. Flexibility Suitable for installation in existing systems. Comfort Low-noise operation. Safety Built-in electrical and thermal protection of the pump. User...

Grundfos ALPHA1 is designed for circulating liquids in heating systems. The pumps are suitable for the following systems: • Systems with constant or variable flows where it is desirable to optimise the pump duty point. • Systems with variable flow-pipe temperature. Grundfos ALPHA1 is especially suitable for the following: • Installation in existing systems where the differential pressure of the pump is too high during periods of reduced flow demand. • Installation in new systems for automatic adjustment of the performance to flow demands without the use of bypass valves or similar expensive components....

Control of heating systems Advantages of pump control The heating required in a building varies greatly during the day due to changing outdoor temperatures, solar radiation and heat emanating from human beings, electric appliances, etc. Add to this that the need for heating may vary from one section of the building to another and that the thermostatic valves of some radiators may be turned down by the users. These circumstances will cause an uncontrolled pump to produce an excessive differential pressure when the heating demand is low. Possible consequences: • too high energy consumption • irregular...

Proportional-pressure control Proportional-pressure control adjusts the pump performance to the actual heat demand in the system, but the pump performance follows the selected performance curve, PP1 or PP2. See fig. 9 where PP2 has been selected. See Change of pump performance for further information. Three proportional-pressure curves/settings Constant-pressure control Constant-pressure control adjusts the pump performance to the actual heat demand in the system, but the pump performance follows the selected performance curve, CP1 or CP2. See fig. 10 where CP1 has been selected. See Change of...

Sectional drawing Grundfos ALPHA1 is designed for long and troublefree operation including the canned-rotor type, i.e. pump and motor form an integral unit without shaft seal and with only two gaskets for sealing. The bearings are lubricated by the pumped liquid. These constructions ensure maintenance-free operation. The pumps are characterised by the following: • Permanent-magnet/compact-stator motor which contributes to high efficiency and high starting torque. • Ceramic shaft and radial bearings which contribute to long life. • Carbon thrust bearing which contribute to long life. • Stainless-steel...

The motor is a 4-pole synchronous permanent-magnet motor. The pump controller is incorporated in the control box, which is fitted to the stator housing with screws. Control panel Standard position Fig. 15 Possible control box positions ALPHA cable with plug The plug incorporates cable relief and a locking function for securing the supply cable connection. Fig. 16 ALPHA plug with cable relief and angled ALPHA plug with fixed cable The control panel is located on the front and is connected to the stator via a terminal plug. The control panel has: • a push-button (fig. 14, pos. 1) for selection...

Unique air vent system The pump housing with air separator is installed in systems where the liquid contains so much air that a circulator pump without air separator cannot start or keep up a continuous circulation. The pump housing is available only for upward water flows. The air-containing liquid is guided from the suction port to the nozzle of the air-separating chamber and caused to circulate considerably in the relatively large chamber, thus creating a relatively lower pressure at the back (top) of the chamber. This lower pressure combined with the reduced velocity of the liquid in the...

4. Installation and startup Installation In most cases, the installation of the Grundfos ALPHA1 is reduced to the mechanical installation and the connection to the power supply. The pump must always be installed with horizontal motor shaft. The pump must not be started until the system has been filled with liquid and vented. Furthermore, the required minimum inlet pressure must be available at the pump inlet. The system cannot be vented through the pump. The pump is self-venting and does not require venting before startup. Liquid temperature To avoid condensation in the control box and stator,...

Change of pump performance The pump performance (flow and head) can be changed by pressing the control box push-button as indicated in fig. 20 and the table below. Fig. 20 Pump setting in relation to performance Setting Pump curve Lowest proportionalpressure curve Highest proportionalpressure curve Lowest constantpressure curve Highest constantpressure curve Function The duty point of the pump will move up or down on the lowest proportional-pressure curve, depending on the heat demand in the system. See fig. 20. The head (pressure) is reduced at falling heat demand and increased at rising heat...