Grundfos ALPHA2 25-60 N 130 User manual

GRUNDFOS ALPHA2
Installation and operating instructions
GRUNDFOS INSTRUCTIONS

Declaration of conformity
2
Declaration of conformity
GB: EC declaration of conformity
We, Grundfos, declare under our sole responsibility that the product
GRUNDFOS ALPHA2, to which this declaration relates, is in conformity
with these Council directives on the approximation of the laws of the EC
member states:
— Low Voltage Directive (2006/95/EC).
Standard used: EN 60335-2-51:2003.
— EMC Directive (2004/108/EC).
Standards used: EN 55014-1:2006 and EN 55014-2:1997.
— Ecodesign Directive (2009/125/EC).
Circulators:
Commission Regulation Nos 641/2009 and 622/2012.
Applies only to circulators marked with the energy efficiency index
EEI. See the pump nameplate.
Standards used: EN 16297-1:2012 and EN 16297-2:2012.
This EC declaration of conformity is only valid when published as part of
the Grundfos installation and operating instructions (publication number
95047457 0813).
PL: Deklaracja zgodności WE
My, Grundfos, oświadczamy z pełnąodpowiedzialnością, że nasze
wyroby GRUNDFOS ALPHA2, których deklaracja niniejsza dotyczy, są
zgodne z następującymi wytycznymi Rady d/s ujednolicenia przepisów
prawnych krajów członkowskich WE:
— Dyrektywa Niskonapięciowa (LVD) (2006/95/WE).
Zastosowana norma: EN 60335-2-51:2003.
— Dyrektywa EMC (2004/108/WE).
Zastosowana norma: EN 55014-1:2006 oraz EN 55014-2:1997.
— Dyrektywa Ekoprojektowa (2009/125/WE).
Pompy obiegowe:
Rozporządzenie Komisji (WE) Nr 641/2009 oraz 622/2012.
Dotyczy tylko pomp obiegowych oznaczonych sprawnością
energetycznąEEI. Patrz tabliczka znamionowa na pompie.
Zastosowane normy: EN 16297-1:2012 oraz EN 16297-2:2012.
Deklaracja zgodności WE jest ważna tylko i wyłącznie wtedy kiedy jest
opublikowana przez firmęGrundfos i umieszczona w instrukcji montażu
i eksploatacji (numer publikacji 95047457 0813).
Bjerringbro, 1st August 2013
Svend Aage Kaae
Technical Director
Grundfos Holding A/S
Poul Due Jensens Vej 7
8850 Bjerringbro, Denmark
Person authorised to compile technical file and
empowered to sign the EC declaration of conformity.

English (GB)
3
English (GB) Installation and operating instructions
Original installation and operating instructions.
CONTENTS
Page
1. Symbols used in this document
1. Symbols used in this document 3
2. General description 4
2.1 Advantages of installing a GRUNDFOS ALPHA2 4
3. Identification 5
3.1 Nameplate 5
3.2 Type key 5
4. Applications 6
4.1 System types 6
4.2 Pumped liquids 6
4.3 System pressure 6
4.4 Relative air humidity (RH) 6
4.5 Enclosure class 6
4.6 Inlet pressure 6
5. Mechanical installation 7
5.1 Mounting 7
5.2 Control box positions 8
5.3 Changing the control box position 8
5.4 Insulation of pump housing 9
6. Electrical installation 10
7. Control panel 11
7.1 Elements on the control panel 11
7.2 Display 11
7.3 Light fields indicating the pump setting 11
7.4 Light field indicating the status of Automatic Night
SetBack 11
7.5 Push-button for activation of Automatic Night SetBack 11
7.6 Push-button for selection of pump setting 11
8. Setting the pump 12
8.1 Pump setting for system type 12
8.2 Pump control 12
9. Automatic Night SetBack 13
9.1 Basis for Automatic Night SetBack 13
9.2 Function of Automatic Night SetBack 13
10. Systems with bypass valve between flow and return
pipes 14
10.1 Purpose of bypass valve 14
10.2 Manually operated bypass valve 14
10.3 Automatic bypass valve (thermostatically controlled) 14
11. Startup 15
11.1 Before start-up 15
11.2 Venting the pump 15
11.3 Venting of heating systems 15
12. Pump settings and pump performance 16
12.1 Relation between pump setting and pump performance 16
13. Fault finding 17
14. Technical data and installation dimensions 18
14.1 Technical data 18
14.2 Installation dimensions, GRUNDFOS ALPHA2 XX-50,
XX-60 19
15. Performance curves 20
15.1 Guide to performance curves 20
15.2 Curve conditions 21
15.3 Performance curves, ALPHA2 XX-50 22
15.4 Performance curves, ALPHA2 XX-60 23
16. Accessories 24
17. Disposal 24
Warning
Prior to installation, read these installation and
operating instructions. Installation and operation
must comply with local regulations and accepted
codes of good practice.
Warning
The use of this product requires experience with
and knowledge of the product.
Persons with reduced physical, sensory or
mental capabilities must not use this product,
unless they are under supervision or have been
instructed in the use of the product by a person
responsible for their safety.
Children must not use or play with this product.
Warning
If these safety instructions are not observed,
it may result in personal injury.
Warning
If these instructions are not observed, it may lead
to electric shock with consequent risk of serious
personal injury or death.
Caution
If these safety instructions are not observed,
it may result in malfunction or damage to the
equipment.
Note
Notes or instructions that make the job easier
and ensure safe operation.

English (GB)
4
2. General description
The GRUNDFOS ALPHA2 circulator pump is designed for the
circulation of water in heating systems and domestic hot-water
systems.
The pump is suitable for the following systems:
• underfloor heating systems
• one-pipe systems
• two-pipe systems.
The pump incorporates a permanent-magnet motor and
differential-pressure control enabling continuous adjustment of
the pump performance to the actual system requirements.
The pump has a user-friendly front-mounted control panel.
See sections 3. Identification and 7. Control panel.
2.1 Advantages of installing a GRUNDFOS ALPHA2
The installation of a GRUNDFOS ALPHA2 means
easy installation and start-up
• The pump is easy to install.
Thanks to the AUTOADAPT function (factory setting), the pump
can, in most cases, be started without making any settings.
high degree of comfort
• Minimum noise from valves, etc.
low energy consumption
• Low energy consumption compared to conventional circulator
pumps.
Energy efficiency index (EEI)
• The Ecodesign directive for energy-using (EuP) and energy-
related (ErP) products is EU legislation requiring
manufacturers to reduce the overall environmental impact of
their products.
• Circulator pumps will be EuP-ready and comply with the
requirements as from 2015.
Fig. 1 EuP-ready label
TM05 7745 1613

English (GB)
5
3. Identification
3.1 Nameplate
Fig. 2 Example of nameplate
3.2 Type key
TM05 6005 4512
Pos. Description Pos. Description
1 Pump type 8 Energy efficiency index [EEI]
2 Product number 9
Rated current [A]:
• Min.: Minimum current [A]
• Max.: Maximum current [A]
3 Serial number 10
Input power P1 [W]:
• Min.: Minimum input power P1 [W]
• Max.: Maximum input power P1 [W]
4
Production code:
• 1st and 2nd digits = year
• 3rd and 4th digits = week
11 Maximum system pressure [MPa]
5 Enclosure class 12 CE mark and approvals
6 Voltage [V] 13 Country of manufacture
7 Frequency [Hz] 14 Temperature class
Example ALPHA2 15 -50 - 130
Pump type
Nominal diameter (DN) of suction and discharge ports [mm]
Maximum head [dm]
: Cast-iron pump housing
N: Stainless-steel pump housing
A: Pump housing with air separator
Port-to-port length [mm]
1
ALPHA2 15-50 130
AUTO
ADAPT
W
Prod. No. 95047500
00000001
Serial No.
PC 0740 TF110
IP 42 230V ~ 50Hz
MADE IN DENMARK
Max.
Min. 0.05
11/1(A) P1(W) MPa
5
22 1.0
0.19
2
3
4
5
6
7
9
10
11
12
13
14
0.23 - Part 2
8
KM07183

English (GB)
6
4. Applications
4.1 System types
Fig. 3 Pumped liquids and operating conditions
GRUNDFOS ALPHA2 is suitable for
• systems with constant or variable flows where it is desirable to
optimise the setting of the pump duty point.
• systems with variable flow-pipe temperature
• systems where night setback is desired.
4.2 Pumped liquids
Clean, thin, non-aggressive and non-explosive liquids, not
containing solid particles, fibres or mineral oil. See fig. 3.
In heating systems, the water should meet the requirements of
accepted standards on water quality in heating systems, for
example the German standard VDI 2035.
In domestic hot-water systems, it is advisable to use GRUNDFOS
ALPHA2 pumps only for water with a degree of hardness lower
than approx. 14 °dH. For water with a higher degree of hardness,
we recommend a direct-coupled TPE pump.
4.3 System pressure
Maximum 1.0 MPa (10 bar). See fig. 3.
4.4 Relative air humidity (RH)
Maximum 95 %. See fig. 3.
4.5 Enclosure class
IP42. See fig. 3.
4.6 Inlet pressure
Minimum inlet pressure in relation to liquid temperature.
See fig. 3.
TM05 8568 2413
Warning
The pump must not be used for the transfer of
flammable liquids such as diesel oil, petrol and
similar liquids.
Liquid
temperature
Minimum inlet pressure
[MPa] [bar]
≤75 °C 0.005 0.05
90 °C 0.028 0.28
110 °C 0.108 1.08

English (GB)
7
5. Mechanical installation
5.1 Mounting
Fig. 4 Mounting the GRUNDFOS ALPHA2
Arrows on the pump housing indicate the liquid flow direction
through the pump.
See section 14.2 Installation dimensions, GRUNDFOS ALPHA2
XX-50, XX-60.
• Fit the two gaskets supplied when the pump is mounted in the
pipe.
• Install the pump with horizontal motor shaft. See fig. 4.
TM05 8569 2413

English (GB)
8
5.2 Control box positions
Fig. 5 Control box positions
5.3 Changing the control box position
The control box position can be changed in steps of 90 °.
Possible/permissible positions and the procedure of changing the
position of the control box are illustrated in fig. 5.
Procedure:
1. Slacken and remove the four hexagon-socket head screws
holding the pump head with a tee key (M4).
2. Turn the pump head to the desired position.
3. Insert and cross-tighten the screws.
TM05 8570 2413
Warning
The pumped liquid may be scalding hot and
under high pressure.
Drain the system or close the isolating valves on
either side of the pump before the screws are
removed.
Caution
Fill the system with the liquid to be pumped or
open the isolating valves when the position of the
control box has been changed.

English (GB)
9
5.4 Insulation of pump housing
Fig. 6 Insulation of pump housing
The heat loss from the pump and pipework can be reduced by
insulating the pump housing and the pipe. See fig. 6.
As an alternative, polystyrene insulating shells can be fitted to the
pump. See section 16. Accessories.
TM05 8567 2413
Note
Limit the heat loss from the pump housing and
pipework.
Caution
Do not insulate the control box or cover the
control panel.

English (GB)
10
6. Electrical installation
Fig. 7 Electrical connection
Carry out the electrical connection and protection according to
local regulations.
• The pump requires no external motor protection.
• Check that the supply voltage and frequency correspond to
the values stated on the nameplate. See section
3.1 Nameplate.
• Connect the pump to the power supply with the plug supplied
with the pump as shown in fig. 7.
• Light in the control panel shows that the power supply has
been switched on.
TM05 8571 2413
Warning
The pump must be connected to earth .
The pump must be connected to an external
mains switch with a minimum contact gap of
3 mm in all poles.

English (GB)
11
7. Control panel
7.1 Elements on the control panel
Fig. 8 GRUNDFOS ALPHA2 control panel
The control panel comprises:
7.2 Display
The display (fig. 8, pos. 1) is on when the power supply has been
switched on.
The display shows the actual pump power consumption in Watt
(integer) during operation.
If a fault is indicated, correct the fault and reset the pump by
switching the power supply off and on.
7.3 Light fields indicating the pump setting
The pump has eight optional settings which can be selected with
the push-button. See fig. 8, pos. 5.
The pump setting is indicated by eight different light fields.
See fig. 9.
Fig. 9 Eight light fields
See section 12. Pump settings and pump performance for
information about the function of the settings.
7.4 Light field indicating the status of Automatic Night
SetBack
Light in (fig. 8, pos. 3) shows that Automatic Night SetBack is
active. See section 7.5 Push-button for activation of Automatic
Night SetBack.
7.5 Push-button for activation of Automatic Night
SetBack
The push-button (fig. 8, pos. 4) activates/deactivates Automatic
Night SetBack.
Automatic Night SetBack is only relevant for heating systems
prepared for this function. See section 9. Automatic Night
SetBack.
The light field (fig. 8, pos. 3) is on when Automatic Night
SetBack is active.
Factory setting: Automatic Night SetBack = not active.
7.6 Push-button for selection of pump setting
Every time the push-button (fig. 8, pos. 5) is pressed, the pump
setting is changed.
A cycle is eight button presses. See section 7.3 Light fields
indicating the pump setting.
TM03 8919 2707
Pos. Description
1Display showing the actual pump power
consumption in Watt
2 Eight light fields indicating the pump setting
3Light field indicating the status of Automatic Night
SetBack
4Push-button for activation of Automatic Night
SetBack
5 Push-button for selection of pump setting
Note
Faults preventing the pump from operating
properly (for example seizing-up) are indicated in
the display by "- -". See section 13. Fault finding.
Note
If the pump impeller is rotated, for example when
filling the pump with water, sufficient energy can
be generated to light up the display even if the
power supply has been switched off.
1
2
3
4
5
ALPHA2 15-50 130
AUTO
ADAPT
TM03 8926 2707
Number of
button
presses
Light field Description
0AUTOADAPT
(factory setting) AUTOADAPT
1PP1 Lowest proportional-pressure
curve
2PP2 Highest proportional-pressure
curve
3CP1 Lowest constant-pressure
curve
4CP2 Highest constant-pressure
curve
5 III Constant curve, speed III
6 II Constant curve, speed II
7 I Constant curve, speed I
8AUTOADAPT AUTOADAPT
Note
If the pump has been set to speed I, II or III, it is
not possible to select Automatic Night SetBack.
AUTO
ADAPT
III II I AUTO PP1
PP2 CP2
CP1

English (GB)
12
8. Setting the pump
8.1 Pump setting for system type
Fig. 10 Selection of pump setting for system type
Factory setting = AUTOADAPT.
Recommended and alternative pump settings according to fig. 10:
AUTOADAPT (underfloor heating and two-pipe systems)
The AUTOADAPT function adjusts the pump performance to the
actual heat demand in the system. As the performance is
adjusted gradually, it is recommended to leave the pump in the
AUTOADAPT position at least one week before changing the pump
setting.
If you choose to change back to AUTOADAPT, the pump
remembers its last setpoint in AUTOADAPT and resumes the
automatic adjustment of the performance.
Changing from recommended to alternative pump setting
Heating systems are "slow" systems that cannot be set to the
optimum operation within minutes or hours.
If the recommended pump setting does not give the desired
distribution of heat in the rooms of the house, change the pump
setting to the shown alternative.
Explanation to pump settings in relation to performance curves,
see section 12. Pump settings and pump performance.
8.2 Pump control
During operation, the pump head will be controlled according to
the principle "proportional-pressure control" (PP) or "constant-
pressure control" (CP).
In these control modes, the pump performance and consequently
the power consumption are adjusted according to the heat
demand in the system.
Proportional-pressure control
In this control mode, the differential pressure across the pump is
controlled according to the flow.
The proportional-pressure curves are indicated by PP1 and PP2
in the Q/H diagrams. See section 12. Pump settings and pump
performance.
Constant-pressure control
In this control mode, a constant differential pressure across the
pump is maintained, irrespective of the flow.
The constant-pressure curves are indicated by CP1 and CP2 and
are the horizontal performance curves in the Q/H diagrams.
See section 12. Pump settings and pump performance.
TM05 1921 4513
Pos. System type
Pump setting
Recommended Alternative
A Underfloor heating AUTOADAPT*Highest constant-pressure curve (CP2)* or
lowest constant-pressure curve (CP1)*
B Two-pipe systems AUTOADAPT* Highest proportional-pressure curve (PP2)*
C One-pipe systems Lowest proportional-pressure curve (PP1)* Highest proportional-pressure curve (PP2)*
D Domestic water Constant speed, speed I* Constant speed, speed II or III*
* See section 15.1 Guide to performance curves.
AUTO
ADAPT
I
II
III AUTO
ADAPT
I
II
III
AUTO
ADAPT
I
II
III
AUTO
ADAPT
I
II
III
AUTO
ADAPT
I
II
III
AUTO
ADAPT
I
II
III
A
U
T
O
O
O
ADAPT
I
II
III
AUTO
ADAPT
I
II
III
A
U
T
O
O
O
ADAPT
I
II
III
AUTO
ADAPT
I
II
III
A
U
T
O
O
O
ADAPT
I
II
II
I
A
U
T
O
O
O
ADAPT
T
I
II
III
OK (OK)
OK (OK)
OK (OK)
OK (OK)
A
B
C
D

English (GB)
13
9. Automatic Night SetBack
9.1 Basis for Automatic Night SetBack
Fig. 11 Automatic Night SetBack
To ensure the optimum function of Automatic Night SetBack, the
following conditions must be fulfilled:
• The pump must be installed in the flow pipe.
The Automatic Night SetBack function does not work if the
pump is installed in the return pipe.
• The system (boiler) must incorporate automatic control of the
liquid temperature.
Activate Automatic Night SetBack by pressing .
See section 7.5 Push-button for activation of Automatic Night
SetBack.
Light in shows that Automatic Night SetBack is active.
9.2 Function of Automatic Night SetBack
Once Automatic Night SetBack has been activated, the pump
changes automatically between normal duty and night setback.
See section 12. Pump settings and pump performance.
Changeover between normal duty and night setback is dependent
on the flow-pipe temperature.
The pump automatically changes over to night setback when a
flow-pipe temperature drop of more than 10-15 °C within approx.
2 hours is registered. The temperature drop must be at least
0.1 °C/min.
Changeover to normal duty takes place without a time lag when
the flow-pipe temperature has increased by approx. 10 °C.
TM05 8151 2013
Warning
Pumps built into gas boilers with a small water
content must never be set to Automatic Night
SetBack.
Note
If speed I, II or III is selected, the Automatic Night
SetBack is deactivated.
Note
It is not necessary to reactivate Automatic Night
SetBack if the power supply has been switched
off.
If the power supply is switched off when the
pump is running on the curve for Automatic Night
SetBack, the pump will start in normal operation.
See section 12. Pump settings and pump
performance.
The pump changes back to the curve for
Automatic Night SetBack when the condition for
Automatic Night SetBack is fulfilled again. See
section 9.2 Function of Automatic Night SetBack.
Note
If the heating system is "undersupplied"
(insufficient heat), check whether Automatic
Night SetBack is activated. If yes, deactivate this
function.
AUTO
ADAPT
I
II
III AUTO
ADAPT
I
II
III
W
AUTO
ADAPT
I
II
III
ALPHA2
W
A
U
T
T
O
O
OO
O
O
O
O
O
O
O
O
O
O
O
AD
DAP
PT
P
P
P
D
DAP
PT
P
P
P
P
H
A
2

English (GB)
14
10. Systems with bypass valve between flow and
return pipes
10.1 Purpose of bypass valve
Fig. 12 Systems with bypass valve
Bypass valve
The purpose of the bypass valve is to ensure that the heat from
the boiler can be distributed when all valves in the underfloor-
heating circuits and/or thermostatic radiator valves are closed.
System elements:
• bypass valve
• flowmeter, pos. A.
The minimum flow must be present when all valves are closed.
The pump setting depends on the type of bypass valve used, i.e.
manually operated or thermostatically controlled.
10.2 Manually operated bypass valve
Follow this procedure:
1. Adjust the bypass valve with the pump in setting I (speed I).
The minimum flow (Qmin.) for the system must always be
observed. Consult the manufacturer's instructions.
2. When the bypass valve has been adjusted, set the pump
according to section 8. Setting the pump.
10.3 Automatic bypass valve (thermostatically
controlled)
Follow this procedure:
1. Adjust the bypass valve with the pump in setting I (speed I).
The minimum flow (Qmin.) for the system must always be
observed. Consult the manufacturer's instructions.
2. When the bypass valve has been adjusted, set the pump to
the lowest or highest constant-pressure curve.
Explanation to pump settings in relation to performance
curves, see section 12. Pump settings and pump
performance.
TM05 8150 2013
BYPASS
Q min.
1
2
33
I
II
III POWER
ON
OK (OK)
I
II
III POWER
ON
OK (OK)
I
II
III POWER
ON
OK (OK)
I
II
III POWER
ON I
II
III POWER
ON
I
II
III
P
O
WER
ER
ON
OK (OK)
12 13
A

English (GB)
15
11. Startup
11.1 Before start-up
Do not start the pump until the system has been filled with liquid
and vented. The required minimum inlet pressure must be
available at the pump inlet. See sections 4. Applications and
14. Technical data and installation dimensions.
11.2 Venting the pump
Fig. 13 Venting the pump
The pump is self-venting. It need not be vented before start-up.
Air in the pump may cause noise. This noise will cease after a few
minutes running.
Quick venting of the pump can be obtained by setting the pump to
speed III for a short period, depending on system size and
design.
When the pump has been vented, i.e. when the noise has
ceased, set the pump according to the recommendations. See
section 8. Setting the pump.
The system cannot be vented through the pump. See section
11.3 Venting of heating systems.
11.3 Venting of heating systems
Fig. 14 Venting of heating systems
The heating system can be vented via an air escape valve
installed above the pump. When the heating system has been
filled with liquid, follow this procedure:
1. Open the air escape valve.
2. Set the pump to speed III.
3. Let the pump run for a short period, depending on system size
and design.
4. When the system has been vented, i.e. when the possible
noise has ceased, set the pump according to the
recommendations. See section 8. Setting the pump.
Repeat the procedure, if necessary.
TM05 8675 2613
Caution
The pump must not run dry.
TM05 8566 2613
Caution
The pump must not run dry.

English (GB)
16
12. Pump settings and pump performance
12.1 Relation between pump setting and pump performance
Figure 15 shows the relation between pump setting and pump performance by means of curves. See also section 15. Performance
curves.
Fig. 15 Pump setting in relation to pump performance
TM03 9208 3607
Setting Pump curve Function
AUTOADAPT
(factory setting)
Highest to lowest
proportional-pressure
curve
The AUTOADAPT function enables ALPHA2 to control the pump performance automatically
within a defined performance range. See fig. 15:
• Adjusting the pump performance to the size of the system.
• Adjusting the pump performance to the variations in load over time.
In AUTOADAPT, the pump is set to proportional-pressure control.
PP1 Lowest proportional-
pressure curve
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. 15.
The head (pressure) is reduced at falling heat demand and increased at rising heat demand.
PP2 Highest proportional-
pressure curve
The duty point of the pump will move up or down on the highest proportional-pressure curve,
depending on the heat demand in the system. See fig. 15.
The head (pressure) is reduced at falling heat demand and increased at rising heat demand.
CP1 Lowest constant-
pressure curve
The duty point of the pump will move out or in on the lowest constant-pressure curve,
depending on the heat demand in the system. See fig. 15.
The head (pressure) is kept constant, irrespective of the heat demand.
CP2 Highest constant-
pressure curve
The duty point of the pump will move out or in on the highest constant-pressure curve,
depending on the heat demand in the system. See fig. 15.
The head (pressure) is kept constant, irrespective of the heat demand.
III Speed III
The pump runs at a constant speed and consequently on a constant curve.
In speed III, the pump is set to run on the maximum curve under all operating conditions.
See fig. 15.
Quick venting of the pump can be obtained by setting the pump to speed III for a short period.
See section 11.2 Venting the pump.
II Speed II
The pump runs at a constant speed and consequently on a constant curve.
In speed II, the pump is set to run on the intermediate curve under all operating conditions.
See fig. 15.
I Speed I
The pump runs at a constant speed and consequently on a constant curve.
In speed I, the pump is set to run on the minimum curve under all operating conditions.
See fig. 15.
The pump changes to the curve for Automatic Night SetBack, i.e. absolute minimum
performance and power consumption, provided certain conditions are met. See section
9. Automatic Night SetBack.
III
II
I
AUTO
ADAPT
AUTO
ADAPT
PP1 PP2CP1CP2
H
Q

English (GB)
17
13. Fault finding
Warning
Before starting work on the pump, switch off the
power supply. Make sure that the power supply
cannot be accidentally switched on.
Fault Control panel Cause Remedy
1. The pump does not
run.
Light off.
a) A fuse in the installation is blown. Replace the fuse.
b) The current-operated or voltage-
operated circuit breaker has tripped
out.
Cut in the circuit breaker.
c) The pump is defective. Replace the pump.
Display shows "- -".
a) Power supply failure. The power
supply might be too low.
Check that the power supply falls within
the specified range.
b) The pump is blocked. Remove the impurities.
2. Noise in the system.
Shows normal operating
status.
a) Air in the system. Vent the system. See section
11.3 Venting of heating systems.
b) The flow is too high. Reduce the suction head. See section
12. Pump settings and pump
performance.
3. Noise in the pump.
Shows normal operating
status.
a) Air in the pump. Let the pump run. It vents itself over
time. See section 11.2 Venting the
pump.
b) The inlet pressure is too low. Increase the inlet pressure or check the
air volume in the expansion tank, if
installed.
4. Insufficient heat. Shows normal operating
status.
a) The pump performance is too low. Increase the suction head. See section
12. Pump settings and pump
performance.

English (GB)
18
14. Technical data and installation dimensions
14.1 Technical data
To avoid condensation in the control box and stator, the liquid
temperature must always be higher than the ambient
temperature.
Supply voltage 1 x 230 V - 10 %/+ 10%, 50/60 Hz, PE.
Motor protection The pump requires no external motor protection.
Enclosure class IP42.
Insulation class F.
Relative air humidity Maximum 95 %.
System pressure Maximum 1.0 MPa, 10 bar, 102 m head.
Inlet pressure
Liquid temperature Minimum inlet pressure
≤+75 °C 0.05 bar, 0.005 MPa, 0.5 m head
+90 °C 0.28 bar, 0.028 MPa, 2.8 m head
+110 °C 1.08 bar, 0.108 MPa, 10.8 m head
EMC EN 55014-1:2006 and EN 55014-2:1997.
Sound pressure level The sound pressure level of the pump is lower than 43 dB(A).
Ambient temperature 0 to +40 °C.
Temperature class TF110 to CEN 335-2-51.
Surface temperature The maximum surface temperature will not exceed +125 °C.
Liquid temperature +2 to +110 °C.
Ambient
temperature
[°C]
Liquid temperature
Min.
[°C]
Max.
[°C]
02110
10 10 110
20 20 110
30 30 110
35 35 90
40 40 70
Caution
In domestic hot-water systems, we recommend to
keep the liquid temperature below +65 °C to
eliminate the risk of lime precipitation.

English (GB)
19
14.2 Installation dimensions, GRUNDFOS ALPHA2 XX-50, XX-60
Dimensional sketches and table of dimensions
Fig. 16 Dimensional sketches, ALPHA2 XX-50, XX-60
* For UK only.
TM03 9215 3912
Pump type
Dimensions
L1 B1 B2 B3 B4 H1 H2 H3 G
ALPHA2 15-50 130* 130 78 78 46 49 27 129 58 1 1/2
ALPHA2 15-60 130* 130 78 78 46 49 27 129 58 1 1/2
ALPHA2 15-50 N 130* 130 - - 47 48 26 127 - 1 1/2
ALPHA2 20-50 N 150* 150 - - 49 49 28 127 - 1 1/4

English (GB)
20
15. Performance curves
15.1 Guide to performance curves
Each pump setting has its own performance curve (Q/H curve). However, AUTOADAPT covers a performance range.
A power curve (P1 curve) belongs to each Q/H curve. The power curve shows the pump power consumption (P1) in Watt at a given Q/H
curve.
The P1 value corresponds to the value that can be read from the pump display. See fig. 17:
Fig. 17 Performance curves in relation to pump setting
For further information about pump settings, see sections
7.3 Light fields indicating the pump setting
8. Setting the pump
12. Pump settings and pump performance.
TM03 9161 3507
Setting Pump curve
AUTOADAPT
(factory setting) Setpoint within the green marked area
PP1 Lowest proportional-pressure curve
PP2 Highest proportional-pressure curve
CP1 Lowest constant-pressure curve
CP2 Highest constant-pressure curve
III Constant speed, speed III
II Constant speed, speed II
I Constant speed, speed I
Curve for Automatic Night SetBack
AUTO
ADAPT
AUTO
III
II
I
ADAPT
PP1 PP2CP1CP2
Q
P1
H
Q
III
II
I