Commissioning; Check The Diaphragm Pressure Vessel - Wilo HiMulti 3 H Serie Einbau- Und Betriebsanleitung

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• The domestic water system is prepared for con-
nection to a 3~400 V mains ex works. If con-
nected to a mains with 3~230 V, the terminal
bridges in the motor's terminal box must be
reset accordingly before establishing the mains
connection (Fig. 7b, item j and k).
The electrical plug connections shall be installed
where they are protected against overflowing
water and against moisture. The electrical system
shall be installed acc. to the specifications in the
corresponding installation and operating instruc-
tions. The technical data of the circuits to be con-
nected must be checked to ensure compliance with
the electrical data of the domestic water system.
Observe the rating plate data of the pump motor
for this.
The mains fuse shall be a 10 A slow-blow fuse.
DANGER! Risk of fatal injury!
As a protective measure, the electrical system
must be earthed correctly (i.e. in accordance with
the local regulations and conditions. Connections
provided for this purpose are marked accordingly
(earth terminal on motor).
NOTE:
Never lift, transport or secure the domestic water
system by the mains connection cable. Do not
spray water directly at the pump.
Damaged cables or plugs must be replaced with
the corresponding spare parts by the manufac-
turer or the manufacturer's customer service. The
electrical connection must be made in accordance
with the (Fig. 6/7).
Only for EM version:
When using an additional float switch, for example
for switching off in case of low water, it must be
connected according to the diagram (Fig. 10a or
10b, item 3).

8 Commissioning

To avoid the pump running dry, it is necessary to
check before commissioning that there is enough
water in the open supply container or the well, or that
the supply pressure in the inlet pipe is at least 0.5 bar.
If a float switch or electrodes are used for protect-
ing against running dry, they must be positioned
so that the domestic water system switches off at
a water level which would result in air being
sucked in.
pI
[bar] 2 2.5
PN2
[bar] 1.8 2.3
Table 1:
Gas supply pressure PN2 diaphragm pressure ves-
sel in relation to the switch-on pressure pI
36
3 3.5 4 4.5 5
2.8 3.2 3.7 4.2 4.7
CAUTION!
The pump must not be allowed to run dry. Dry
running, even for a short period, can result in
damage to the mechanical seal. Damage to the
pump due to running dry will not be covered by
the manufacturer's warranty.
The system must be filled with water before start-
ing the domestic water system (section 8.2).

8.1 Check the diaphragm pressure vessel

In order for the domestic water system to operate
correctly, it is necessary to have a gas supply pres-
sure in the diaphragm pressure vessel that is
appropriate for the switch-on pressure. In the fac-
tory setting, the gas space of the diaphragm pres-
sure vessel is filled with nitrogen and set to a
particular supply pressure (see rating plate). The
gas pressure should be checked again before
commissioning and after changes to the pressure
switch settings. For this purpose, the domestic
water system must be de-energised and the dia-
phragm pressure vessel depressurised on the
water side. The gas supply pressure shall be
checked at the gas filling valve of the diaphragm
pressure vessel (Fig. 1 and 2, item 9) by means of
an air pressure gauge (Figs. 9a to 9c)
WARNING! Risk of suffocation by nitrogen!
Measuring, replenishing and venting of nitrogen
at the diaphragm pressure vessel is only allowed
to be performed by qualified specialist personnel.
WARNING! Danger of injury!
Excessive gas supply pressure can lead to
destruction of the diaphragm pressure vessel.
The maximum permitted operating pressure on
the rating plate must not be exceeded. Monitor
the gas supply pressure by measuring during the
filling procedure. When measuring instruments
with different scale divisions (unit of dimension)
are used, it is essential to comply with the
instructions for converting! Comply with the
general safety regulations for working with
pressure vessels.
The value of the gas supply pressure (PN2) should
be approx. the pump switch-on pressure (pI)
less 0.2-0.5 bar (or pump switch-on pressure less
10%) (see Table 1)!
If the gas supply pressure is too low, it must be cor-
rected by replenishing gas. When replenishing, we
recommend using nitrogen because this gas mini-
mises the risk of corrosion in the tank, as well as pre-
venting losses through diffusion. If the gas supply
pressure is too high, correct it by venting gas from
the valve.
5.5 6 6.5 7 7.5
5.2 5.7 6.1 6.6 7.1
Conversion of pressure units:
1 bar = 100000 Pa = 0.1 MPa = 0.1 N/mm²
= 10200 kp/m² = 1.02 kp/cm² (at)
1 bar = 0.987 atm = 750 Torr = 10.2 m/Ws
8 8.5 9 9.5 10
7.5 8 8.5 9 9.5
WILO SE 07/2018