Grundfos CU 301 User manual

CU 301
Installation and operating instructions
CU 301
Installation and operating instructions
(all available languages)
http://net.grundfos.com/qr/i/99406808
GRUNDFOS INSTRUCTIONS

CU 301
English (GB)
Installation and operating instructions ..................................4
Español (ES)
Instrucciones de instalación y funcionamiento............................30
Français (FR)
Notice d'installation et de fonctionnement...............................58
3
Table of contents

English (GB) Installation and operating instructions
Original installation and operating instructions
Table of contents
1. General information ............. 4
1.1 Hazard statements .............. 4
1.2 Notes ..................... 4
2. Installing the product ............ 5
2.1 Mechanical installation ............ 5
2.2 Electrical connection ............. 6
2.3 Positioning the pressure sensor ....... 7
2.4 Precharge pressure setting .......... 8
2.5 Pressure relief valve ............. 8
3. Product introduction ............ 8
3.1 Product description .............. 8
3.2 System sizing .................11
3.3 Intended use .................12
4. Control functions ..............13
4.1 On/off button .................13
4.2 Indication of pump operation .........13
4.3 Pressure setting................14
4.4 Button locking .................14
4.5 Alarm functions ................14
4.6 Service alarm .................15
4.7 Dry-running protection ............15
4.8 Position of LEDs ...............16
4.9 Grundfos GO Remote menu overview ....17
5. Setting the product .............18
5.1 CU 301 with Grundfos GO Remote .....18
5.2 Status .....................18
5.3 Settings ....................19
6. Servicing the product ............22
7. Fault finding the product ..........23
7.1 Fault finding with Grundfos GO Remote . ..23
8. Technical data ................27
9. Disposing of the product ..........29
10. Document quality feedback ........29
1. General information
Read this document before you install the
product. Installation and operation must
comply with local regulations and accepted
codes of good practice.
1.1 Hazard statements
The symbols and hazard statements below may
appear in Grundfos installation and operating
instructions, safety instructions and service
instructions.
DANGER
Indicates a hazardous situation which, if
not avoided, will result in death or serious
personal injury.
WARNING
Indicates a hazardous situation which, if
not avoided, could result in death or
serious personal injury.
CAUTION
Indicates a hazardous situation which, if
not avoided, could result in minor or
moderate personal injury.
The hazard statements are structured in the following
way:
SIGNAL WORD
Description of the hazard
Consequence of ignoring the warning
• Action to avoid the hazard.
1.2 Notes
The symbols and notes below may appear in
Grundfos installation and operating instructions,
safety instructions and service instructions.
Observe these instructions for explosion-
proof products.
A blue or grey circle with a white graphical
symbol indicates that an action must be
taken.
A red or grey circle with a diagonal bar,
possibly with a black graphical symbol,
indicates that an action must not be taken
or must be stopped.
If these instructions are not observed, it
may result in malfunction or damage to the
equipment.
Tips and advice that make the work easier.
4
English (GB)

2. Installing the product
DANGER
Electric shock
Death or serious personal injury
‐Before starting any work on the
product, make sure that the power
supply has been switched off and that
it cannot be accidentally switched on.
‐Use the recommended fuse size.
‐Check that the supply voltage
corresponds to the values stated on
the nameplate.
‐The user or the installer is responsible
for correct earthing and protection
according to local regulations.
2.1 Mechanical installation
You can install CU 301 both indoors and outdoors.
The control unit must not be exposed to direct
sunlight.
2.1.1 Mounting CU 301
CU 301 is designed for wall mounting.
The box has six mounting holes (∅4). See fig.
Dimensions. The dimensions are in mm.
CU 301 must be mounted as follows:
• Horizontally to allow condensed water, if any, to
escape. See fig. Dimensions.
On a plane surface to avoid deformation of the box.
104.5
104.5
100
140.5
TM017864
Dimensions
CU 301 is supplied with special gaskets for the Pg
cable entries. The special gaskets are suitable for flat
cables and single-core cables.
5
English (GB)

2.2 Electrical connection
For recommended fuse sizes. See section
8. Technical data.
CU 301 has two terminal blocks:
• Screw terminals 1 to 4.
• Spring terminals 5 to 7.
Furthermore, CU 301 is equipped with two screw
terminals for the protective-earth conductors (PE).
The on/off button on CU 301 must not be used as a
safety switch when installing and servicing the pump.
POWER
PE
PUMP
PE
L
N
4
13
2
SENSOR
567
+24V IN GND
L
N
TM017720
Electrical connection of CU 301
Legend
Pos. Description
1Standard pressure sensor. + 24 VDC,
brown conductor, terminal 5.
2Standard pressure sensor. Input signal,
black conductor, terminal 6.
3Standard pressure sensor. Screen,
terminal 7.
4 Standard pressure sensor.
Related information
8. Technical data
2.2.1 Mains supply
POWER, terminals 1, 2 and PE
Connect terminals 1 and 2 to the phase and neutral
conductors of the mains supply. Each terminal can be
connected to any of the two conductors.
Connect the PE terminal to the green and yellow
earth conductor. Each PE terminal must be
connected to an earth conductor of its own.
Maximum cross-section of the conductors to be
connected is 6 mm2.
Back-up fuse: Maximum 16 A.
The conductors of the mains supply must
not be connected to terminals 3 and 4
(PUMP).
2.2.2 Pump supply
PUMP, terminals 3, 4 and PE
Connect terminals 3 and 4 to the phase and neutral
conductor of the pump. Each terminal can be
connected to any of the two conductors.
Connect the PE terminal to the green and yellow
earth conductor. Each PE terminal must be
connected to an earth conductor of its own.
Maximum cross-section of the conductors to be
connected is 6 mm2.
Pressure sensor
DANGER
Electric shock
Death or serious personal injury
‐The total load of terminal 5, +24 VDC,
must not exceed 100 mA.
SENSOR, terminals 5, 6 and 7:
Terminals 5, 6 and 7 (SENSOR) are used for the
pressure sensor.
Sensor signals:
The sensor to be connected must give signals within
one of the following ranges:
• 0-10 V.
• 2-10 V.
• 0-20 mA.
• 4-20 mA.
Changeover between current and voltage signals is
carried out by means of Grundfos GO Remote.
6
English (GB)

Operating relay
RELAY, terminals 8 and 9:
Terminals 8 and 9 (RELAY) are used for the
connection of an external signal transmitter (sound or
light).
The operating relay is a normally open (NO) contact
when the pump is not running, and closes while the
pump is running.
• Maximum current: 0.5 A.
• Maximum voltage: 230 VAC.
PE
PE
POWER PUMP
8 5 7 4
12
relpol
RM85-3021-25-1024
MADE IN POLAND
4080
AC 250 V 16 A
DC 24 V
5 6 7
+24V IN GND
8 5
7 4
12
relpol
RM85-3021-25-1024
MADE IN POLAND
4080
AC 250 V 16 A
DC 24 V
9 8
RELAY
Max. 0.5 A
8 5
7 4
12
relpol
RM85-3021-25-1024
MADE IN POLAND
4080
AC 250 V 16 A
DC 24 V
9 8
RELAY
Max. 0.5 A
SENSOR
TM070764
Electrical connection of the operating relay
2.3 Positioning the pressure sensor
Pressure losses often cause inconvenience to the
user. CU 301 keeps the pressure constant in the
place where the pressure sensor is positioned.
3
12
CU 301
TM017862
Pressure sensor position
Pos. Description
1 Tap 1
2 Tap 2
3 Pressure sensor
In fig. Pressure sensor position, tap 1 is placed close
to the pressure sensor. Therefore, the pressure is
kept nearly constant at tap 1, as the friction loss is
small. At the shower and tap 2, the friction loss is
bigger. This, of course, depends on the pipes.
However, old and furred-up pipes may cause
inconvenience due to friction loss.
Example: A person is in the shower. Tap 2 is opened.
The increased flow causes pressure loss in the pipe,
and even though CU 301 is keeping the pressure
constant at the pressure sensor, the person in the
shower feels the pressure loss.
If the pressure sensor is placed closer to the shower
tap, CU 301 increases the pressure when the flow
rate is increased. Then the pressure at the shower
and tap 2 is kept constant, but the pressure at tap 1 is
increased.
We recommend that the pressure sensor is
positioned as close to the places of consumption as
possible.
Related information
7.1 Fault finding with Grundfos GO Remote
7
English (GB)

2.4 Precharge pressure setting
The precharge pressure of the diaphragm tank must
be set to 70 % of the pressure setting in order to use
the tank to the limit of its capacity. This is of course
especially important when the tank volume is limited
to 8 litres.
Use the values in the following table:
Setting
[bar]
Precharge pressure
[bar]
2 1.4
2.5 1.8
3 2.1
3.5 2.5
4 2.8
4.5 3.2
5 3.5
If the precharge pressure is higher than the pressure
setting, the system is not able to control the pressure.
If the user wants to adjust the pressure without
changing the precharge pressure of the diaphragm
tank, the precharge pressure must be equal to the
lowest pressure setting used. This means that the
control works but that the pressure fluctuations might
increase. In such cases, we recommend that you use
a larger diaphragm tank, for example a tank of double
size.
2.5 Pressure relief valve
In order to provide protection against the possibility of
an overpressurization, a pressure relieve valve must
be installed down stream of the well head. The
setpoint of the pressure relief valve must be at least
30 psi above the pressure setting. See section
5. Setting the product.
If a relief valve is installed, we recommend that its
outlet is plumbed into an appropriate drainage point.
3. Product introduction
3.1 Product description
The system maintains a constant pressure within the
maximum pump performance in spite of a varying
water consumption.
Figure Example installation shows an example of an
installation with constant-pressure control.
2
1
3
4
TM080250
Example installation
Pos. Description
1 CU 301
2 Diaphragm tank
3 Pressure sensor
4 SQE pump
The pressure is registered by means of the pressure
sensor, which transmits a signal to CU 301. CU 301
adjusts the pump performance accordingly by
changing the pump speed.
Mains borne signalling
The communication between CU 301 and the pump is
effected via the power cable.
This communication principle is called mains borne
signalling, or power line communication. Using this
principle means that no additional cables to the pump
are required.
The communication of data is effected by means of a
high-frequency signal transmitted to the power cable
and led into the electronics unit by means of signal
coils incorporated in the motor and CU 301
respectively.
In situations where multiple CU 301 pump power
cables are run parallel in wiring trays or conduit and
less than 25-30 cm apart, the possibility for undesired
communication between units exists. When this
occurs, intermittent or continuous "No contact" is
typically seen. Other unexpected errors may also be
seen.
8
English (GB)

Figure Principle of mains borne signalling (power line
communication) shows the principle of mains borne
signalling between CU 301 and the pump.
CU 301
15
2
3
49
6
8
7
TM070560
Principle of mains borne signalling (power line
communication)
Pos. Description
1 Supply to the electronics
2 Signal coils
3 Capacitor
4Electronics for the control of the
communication
5 On/off button
6 Sensor signal
7 Power supply
8 Communication signals
9 Grundfos GO Remote
When does the pump start
The pump starts as a consequence of the following:
• a high flow
• a low pressure
• a combination of both.
To ensure that the pump starts when water is
consumed, a flow detection is required. The flow is
detected via pressure changes in the system. When
water is consumed, the pressure drops accordingly
depending on the size of the diaphragm tank and the
water flow:
• at a low flow, the pressure drops slowly.
• at a high flow, the pressure drops quickly.
2
4
1
3
TM018545
Pos. Description
1 Pressure
2 Low flow
3 Time
4 High flow
When the pressure drops 0.1 bar/s or faster, the
pump starts immediately.
If a diaphragm tank of 8 litres is used, the pump starts
at a flow rate of approximately 0.18 m3/h. If a larger
tank is used, the flow must be higher before the pump
starts.
Consumption up to 0.18 m3/h
The pump starts when the pressure drops to 0.5 bar
below the pressure setting.
The pump runs until the pressure is 0.5 bar above the
pressure set.
Flow detection
During pump operation, meaning when water is
consumed, CU 301 adjusts the pump speed to
maintain a constant pressure. In order to stop the
pump when no water is consumed, CU 301 performs
flow detection every 10 seconds.
9
English (GB)

The pump speed is reduced until a small pressure
drop is registered. This pressure drop indicates that
water is consumed and the pump speed is resumed.
See fig. Flow detection every 10 seconds during
operation.
If the pump speed reduces without any pressure drop
being registered, this indicates that no water is
consumed. The diaphragm tank is filled with water
and the pump stops.
1
10 s 10 s
2
3
TM018546
Flow detection every 10 seconds during operation
Pos. Description
1 Flow detection
2 Pressure
3 Time
System limits
Even though, CU 301 controls the pressure within ±
0.2 bar, bigger pressure variations may occur in the
system. If the consumption is suddenly changed, for
example if a tap is opened, the water must start
flowing before the pressure can be made constant
again. Such dynamic variations depend on the pipes,
but, typically, they will lie between 0.5 and 1 bar.
If the desired consumption is higher than the quantity
the pump is able to deliver at the desired pressure,
the pressure follows the pump curve as illustrated in
fig. Possible pressure variations during constant-
pressure operation.
2
1
A
345
6
8
7
TM018634
Possible pressure variations during constant-
pressure operation
Pos. Description
1Stop
+ 0.5 bar
2 Pressure
3Start
- 0.5 bar
4 Controlling ± 0.2 bar
5 Dynamic variations ± 0.5 bar
6 Flow
7 0.18
8m3/h
A Pressure set
10
English (GB)