BWT CRU 38 User manual

BW T CR U 38, 200, 600
Concentrate Reusable Unit
Installation and Operating manual EN

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Content
1General information ..............................................................3
2Explanation of words ............................................................3
3Functional description ............................................................3
4Installation of BWT Compact CRU ...........................................4
4.1 Positioning ................................................................................................................4
4.2 Water connections.....................................................................................................4
4.3 Electric installation .....................................................................................................4
5Start and operation of BWT CRU ............................................5
6Technical specifications and settings.......................................5
7Survey of alarm conditions settings .......................................6
7.1 Trouble shooting ........................................................................................................7
8Technical specifications ..........................................................9
9Annex .................................................................................10
9.1 El-diagram ..............................................................................................................10
9.2 PI diagram ..............................................................................................................12
9.3 Arrangement drawing ..............................................................................................13
9.3.1 Arrangement drawing: BWT CRU 38, 200, 600 ..................................................13
9.4 Start-up test .............................................................................................................14
9.5 Spare parts drawings...............................................................................................15
9.5.1 Spare parts drawing: BWT CRU 38, 200, 600 ....................................................15
9.6 Spare parts list BWT CRU .........................................................................................16
10 Disposal ..............................................................................17
11 Declaration of Conformity....................................................18

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1General information
This operating and maintenance manual
applies to BWT CRU.
This manual should be read carefully prior to
installation and commissioning of the BWT
CRU.
Important! Enclosed “Start-up test”(section 9.4)
shall be completed.
Correct installation and operation is a
condition for our 12-month warranty.
With its compact and complete design, the
BWT CRU is easy to install as all internal
installations have been pre-assembled and
tested in our workshop.
The BWT CRU is designed for minimum
service and for long and unprob-lematic
operation. This, however, is determined by
correct installation and maintenance.
2Explanation of words
There will be a few technical explanations in
this manual, which we describe below.
CRU: Concentrate Reusable Unit
Concentrate: Is the water that is led to outlet
or to BWT CRU. This wa-ter contains the salts
and minerals that have been removed from the
raw water.
Raw water: Is the water which is led directly
to RO-plant and which must be desalinated in
the RO-plant.
Membranes: Is the filter of the plant which by
high pressure and flow is capable of desali-
nating the raw water.
RO: The abbreviation for Reverse Osmosis.
Transport pump: Is the pump which transports
the treated water from the tank to the con-
sumer.
Level switch: Is a switch, which gives a signal
when the RO-plant must either be started or
stopped, and it stops the transport pump in
case of dry-running of the tank.
3Functional description
The BWT CRU is a unit that reuses concentrate
for flushing water. In this way the BWT CRU
will reduce water wastage and increase WCF
(Water Conversion Factor) of the RO plant
significantly.
Note! Concentrate contains a high percentage
of salts and minerals for which reason it is not
recommended to be used as drinking water.
BWT CRU is equipped with a 38, 200 or
600l tank with built-on level measurement and
pump section. The level switch controls start
and stop of the transport pump. The unit has a
built-in protection against dry-running of the
transport pump. The pump section consists of
a transport pump which is equipped with a
solenoid valve at the raw water inlet and a
pressure switch and hydrophore at the outlet.
When there is concentrate in the tank and the
pressure switch detects a drop in the pressure,
the transport pump will start , i.e. when there
is a request for water. The pump stops when
the pressure increases. The hydrophore
equalizes pressure surges at start and stop of
the pump. The non-return valve protects
against air getting into the system. When tank
is full with concentrate and there is no water
consumption the incoming concentrate will be
led to the drain through the overflow branch
(on the backside of the unit). Note! The
overflow branch must be connected to the

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drain with the drain hose before taking BWT
CRU in use.
4Installation of BWT CRU
4.1 Positioning
The BWT CRU must be placed in frost-free
surroundings on a level foun-dation. The
foundation shall be able to carry a weight
load of 78, 250 or 670 kg. The weight load
of any other plants should also be taken into
account!
Important! There must be free space at either
side of the unit for water installations. In case
of a stoppage, a situation may occur where
the concentrate level in the unit overflows.
There must always be a floor drain nearby,
located so that the water cannot cause
damage. There must be easy access to the
main switch of the plant.
4.2 Water connections
Note! All water connections of the unit shall
be installed in compliance with local
regulations. (DS439)
Concentrate inlet: 12 mm hose
Raw water inlet: 3/4” male thread
Outlet: 3/4” male thread
Drain: 1¼” hose
Important! If the water connection for
consumption is too small there is a risk of
outage on the unit due to lacking water
pressure/amount. In general, pressure losses
should be mini-mized.
Important! Concentrate can accelerate
corrosion or deposit scaling in the water
system. Therefore, always use corrosion-proof
piping for the concentrate, e.g. stainless steel
or PVC pipe.
Important! There must be an air gap (min.
20mm) between the drain hose and drain
water level, or else drain water can be sucked
back into the tank.
Important! The drain hose may never be bent
or in any other way obstructed, as this can
cause water overflow in the tank.
Important! The pressure switch on the BWT
CRU, shall be regulated to match the inlet
pressure in the general water system
4.3 Electric installation
Note! The electric connections must be made
in compliance with local regulations. The elec-
tric connection to the BWT CRU must be as
follows:
Voltage: 230 V/50 Hz
Fuse: 10A
Max. power consumption: 1.0 kW
Colour code of power cable:
Blue wire: N
Brown wire: L
Yellow/green wire: PE

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5Start and operation of BWT CRU
Note! Check before start-up that all water
and electrical connections are made as
described in the previous sections and that
they are in compliance with local regulations.
The transport pump pressure switch and
pressure tank are preset in our factory and do
not need to be adjusted.
Make sure that the overflow branch is
connected to the drain and there is
concentrate flow (max. 400l/h) from BWT
RO plant in to the BWT CRU
Power ON the BWT CRU and check that
the transport pump mo-tor is running. Note!
The transport pump cannot be started until
the tank of the unit has been filled up.
Wait for the tank to be completely filled.
Check that level switch stops the transport
pump automatically when the tank is full.
NOTE: Do not touch the level switch.
Create a large consumption of water for 5
min (the TP-pump needs to be bled of air)
Check that the transport pump starts
automatically.
Check that the pump supplies water and
pressure. If the pump does not supply water
and pressure, see Chapter 8: Trouble-
shooting.
When the transport pump is found to be
working properly, consumption of
concentrate shall be stopped.
Wait for the transport pump to stop
automatically. Note! (on BWT RO reservoir
and BWT CRU units): The transport pump
doesn’t stop until 10-30 sec. after the
consumption has stopped due to the built-in
time delay in the control box.
The BWT CRU has now been
commissioned and is ready for use.
6Technical specifications and
settings
It is possible to change the various time
settings for Start, Stop and Alarm, plus
delayed start-up of pumps.
Use of DIP-switch:
No. 1: (Only available for PERMAQ
COMPACT 41)
No. 2: Transport pump
No. 3: Selection of BWT CRU model
No. 4-6: Transport pump

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7Survey of alarm conditions settings
LED function: In normal operation the LED’s are lit corresponding to the components they represent.
Fault conditions are described in Chapter 8. Trouble shooting
“Re-start ALARM” on TP-pump:
(Nothing is working –
permanent condition)
See: Fault 4
ALARM - Too high water level:
(Nothing is working –
permanent condition)
Option
Too low water level:
(no ALARM, TP-pump stopped)
See: Fault 1
External stop - TP-pump,
can be jumped at start-up
Remove the
cause for external
stop signal
CRU unit is running, everything OK
CRU unit is on Standby
POWER
TRANSPORT
PUMP
(TP-pump)
LEVEL
ALARM
Description
of alarm-
and fault
conditions
Trouble-
shooting/
comments
LED’s are lit
LED’s flashes slowly (½ Hz)
LED’s flashes rapidly (5 Hz)
The unit emits beep tone at Alarm condition (Nothing is working), which can only be neutralized by
rectifying the fault, then switching the plant OFF for 5 seconds and switching ON again.

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7.1 Trouble shooting
This chapter deals with problems that may occur on the plant. Follow the instructions in the relevant
flow diagrams in order to perform a troubleshooting. Warning! ALWAYS pull the POWER PLUG
before replacement of electrical components and wait 3 minutes.
Description
of fault
Reason for fault
Action
Fault 1:
The tank
is empty
Low water level.
Check that the RO-plant is running and there is flow of
concentrate to the BWT CRU. The RO-plant may produce less
concentrate than there is need of for consumption.
Check if too many consumers are connected on the BWT
CRU and switch some off. Let the BWT CRU become
completely filled up.
Check if the level switch float is stuck in top of the reservoir.
Carefully push the level switch float up/down so that it is at
concentrate water level.
Check if the level switch and/or the level switch cable are
defective. If so, replace.
Check the TP-pump (See Fault 1, Fault 2 and Fault 3).
Fault 2:
TP pump
doesn’t run
Switch is at OFF.
Push switch to ON.
Low water level.
Let the reservoir become completely filled up and the TP pump
will start automatically.
Defective pressure
switch.
Short the pressure switch by making a jumper between the
two plugs. If the pump only runs when this jumper is
connected and there is a request for water, then the pressure
switch is defective and must be replaced.
Defective capacitor.
Locate transport pumps capacitor in the control box and
replace it.
Defective fuse.
Check the PCB and replace the fuse
(F3-Circuit Board) of the TP pump.
Defective TP-pump.
Replace TP-pump.
Defective PCB.
Replace PCB.
Float of the level
switch is stuck.
Push the level switch float carefully up/down until it is at
concentrate level.
Defective level
switch.
Replace level switch.
External stop signal
on the TP-pump.
Check and rectify cause of the external stop signal.

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Fault 3:
TP-pump is
running but no
water is
getting to the
consumer
Air in the TP-pump.
The TP-pump needs to be bled of air. Switch power OFF, fill
up the tank and turn switch power back to ON. Let the pump
run a while with a large flow in order to get the remaining air
out of the pump case.
Low water level.
Disconnect the consumer. Let the tank become completely
filled and the TP-pump will start automatically.
Fault 4:
TP-pump
starts and
stops
If the piping
connection is too
small there is a risk
of outages on the
plant due to lacking
water
pressure/amount
etc.
Replace the outlet pipe (water for consumption) with an outlet
pipe with a larger dimension.
Non-return valve is
leaks/defective.
Replace the non-return valve.
The hydrophore is
defective or lacking
air.
Replace the pressure tank and set the pre-pressure at 2.7 bar.
The hydrophore
capacity is too
small.
Contact BWT for technical advice.
Pressure switch set
incorrectly.
Set the pressure switch at 4.0 bar (Stop) and 3.0 bar (Start).

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8Technical specifications
BWT CRU
Designation
Tag
number
CRU 38
CRU 200
CRU 600
Tank volume
38 l
200 l
600 l
Max. concentrate
flow to the CRU
400 l/h
400 l/h
400 l/h
Transport pump
P1
0.85 kW, 4.5A
0.85 kW, 4.5A
0.85 kW, 4.5A
Pump capacity
3 bar / 3 m3/h
3 bar / 3 m3/h
3 bar / 3 m3/h
Height/Width/Depth
810/580/630
mm
810/580/630
mm
810/580/630
mm
Concentrate inlet,
diameter
12 mm
12 mm
12 mm
Consumption water outlet,
diameter
3/4”
3/4”
3/4”
Raw water inlet, diameter
3/4”
3/4”
3/4”
Weight (empty/full)
30/78 kg
50/250 kg
70/670 kg
Water temperature (Min.
/Max.)
5-35°C
5-35°C
5-35°C
Pressure switch
PS01
-0.2 to 8 bar
-0.2 to 8 bar
-0.2 to 8 bar
Solenoid valve, NO
V1
POM
POM
POM
Non-return valve
V2, V3
½”
½”
½”
Overflow, diameter
1”
1”
1”

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9Annex
9.1 El-diagram