Protection Against Dry Running/Low Water Level (Accessory); Diaphragm Pressure Vessel (Accessory) - Wilo SiBoost Smart Série Notice De Montage Et De Mise En Service

The water must be completely replaced after a
long system standstill.
For the simple flushing of the system, we recom-
mend the installation of a T-connector on the end
pressure side of the pressure-boosting system
(if there is a diaphragm pressure vessel on the
pressure side, immediately downstream of it)
upstream of the next shut-off device. Its branch,
provided with a shut-off device, drains into the
waste water system during the flushing process
and has to be dimensioned according to the
maximum volume flow of a single pump (see Fig. 7
and 8, item 28). If it is not possible to achieve free
drainage, the requirements of DIN 1988 T5 must
be observed when connecting a hose, for
example.
7.2.4 Protection against dry running/low water level
(accessory)
Fitting dry-running protection
• Direct connection to the public water mains:
For systems with frequency control for every
pump (SCe), a kit with a pressure sensor is already
installed on the intake side. It monitors the supply
pressure accordingly and transmits this as a cur-
rent signal to the control device. In this case, no
additional accessories are necessary!
On systems without frequency control of every
pump (SCe and SC-FC), screw the protection
against low water level kit (WMS) into the connec-
tion port provided on the suction manifold pipe
and seal (if retrofitting) and make the electrical
connection in the control device according to the
installation and operating instructions and the
control unit circuit diagram (Fig. 6a and 6c).
• In the event of an indirect connection, i.e. for
operation with tanks provided by the customer:
Fit the float switch in the tank so that if the water
level drops to approximately 100 mm above the
draw-off connection, the "low water" switching
signal is transmitted. (If break tanks from the Wilo
range are used, a float switch is already installed
(Fig. 13a and 13b).)
• Alternative: install 3 submersible electrodes in the
break tank. The arrangement must be performed
as follows: a first electrode should be positioned
as an earth electrode just above the base of the
tank (must always be submerged), for the lower
switching level (low water). A second electrode
placed approximately 100 mm above the draw-
off connection. For the upper switching level
(low water rescinded) a third electrode attached
at least 150 mm above the lower electrode. Con-
nect the wiring to the control device according to
the installation and operating instructions and cir-
cuit diagram of the control device.
Nominal diameter
Connection
3
Max. volume flow (m /h)
Table 1
Installation and operating instructions Wilo-SiBoost Smart (FC) ... Helix V/... Helix VE/... Helix EXCEL
DN 20 DN 25 DN 32
(Rp ¾") (Rp 1") (Rp 1¼")
2.5 4.2

7.2.5 Diaphragm pressure vessel (accessory)

For transportation and hygienic reasons, the
diaphragm pressure vessel (8 litre) – which is part
of the scope of delivery – may be delivered
unmounted as an accessories kit. The diaphragm
pressure vessel must be mounted on the through-
flow fitting before commissioning (see Fig. 2a
and 3).
NOTICE
Make sure the throughflow fitting is not twisted.
The fitting is installed correctly when the drain
valve (see also Fig. 3, B) or the flow direction
arrows printed on it are parallel to the manifold
pipe.
For systems with pumps of the Helix EXCEL series
(with unit casing) an optional kit with a diaphragm
pressure vessel is included in scope of delivery.
If an additional larger diaphragm pressure vessel
has to be installed, observe the corresponding
installation and operating instructions.
A throughflow diaphragm pressure vessel accord-
ing to DIN 4807 must be installed for drinking
water installations. When installing a diaphragm
expansion tank, also make sure there is enough
room for maintenance or replacement work.
NOTICE
Diaphragm pressure vessels require regular
testing according to the directive 97/23/EC
(in Germany, also take into account the Operating
Safety Ordinance §§ 15(5) and 17 as well as
Annex 5).
Shut-off devices must be provided upstream and
downstream of the vessel for tests and inspection
and maintenance work on the piping. To prevent
system downtimes, connections for a bypass can
be provided upstream and downstream of the dia-
phragm pressure vessel. Such a bypass (as for
example in the diagram Fig. 7 and 8 item 33) must
be completely removed after completion of the
work, so as to avoid stagnation of the water!
Special maintenance and test instructions can
be taken from the installation and operating
instructions for the diaphragm pressure vessel
concerned.
The system conditions and pumping data of the
system must be taken into account when select-
ing the size of the diaphragm pressure vessel.
When doing so, ensure there is sufficient flow
through the diaphragm pressure vessel. The max-
imum volume flow of the pressure-boosting sys-
tem must not exceed the maximum permissible
volume flow of the diaphragm pressure vessel
connection (see table 1 or the specifications on
the rating plate, and the installation and operating
instructions for the tank).
DN 50 DN 65
Flange Flange
7.2 15 27
English
DN 80 DN 100
Flange Flange
36 56
17