Wilo Helix EXCEL 22 Installation And Operating Instruction page 46

English
7.3 Pipe connection
- Connect the pump to the pipes by using appro-
priate counterflanges, bolts, nuts and gaskets.
CAUTION!
Tightening of bolts must not exceed 80 Nm
Use of impact wrench is prohibited.
- The circulation sense of the fluid is indicated on
the identification label of the pump.
- Pump must be installed in such a way that it is
not stressed by the pipework. The pipes must be
attached so that the pump does not bear their
weight.
- It is recommended that isolation valves be
installed on the suction and discharge side of the
pump.
- Use of expansion joints may mitigate noise and
vibration of the pump.
- As regards the nominal cross-section of the suc-
tion pipe, we recommend a cross-section at least
as large as that of the pump connection.
- A check valve could be placed on the discharge
pipe in order to protect the pump against ham-
mer shock.
- For direct connection to a public drinking water
system, the suction pipe must also have a check
valve and a guard valve.
- For indirect connection via a tank, the suction
pipe must have a strainer to keep any impurities
out of the pump and a check valve.
- In case of half flanges pump design, it is recom-
mended to connect the hydraulic network and
then keep out the plastic fixation links to pre-
vent any leakage risk.
- The cables for the sensor, the external instruction, the
inputs [Ext. Off] and [Aux] must be shielded, and inserted in
the gland M12 or M16.
The metal glands of the converter are adapted
to installation with protective braiding.
46
7.4 Electrical connections
DANGER! Risk of fatal injury!
Hazardous voltage due to the discharge of the
converter capacitors.
• Before any work on the converter, wait for
5 minutes after disconnecting the power supply.
• Check that all electrical connections and con-
tacts are not live.
• Check that the pressure connection terminals
have been allocated correctly.
- The power supply cable (3 phases + earth) must
be inserted into the gland indicated below in
black.
- The glands that aren't used must remain sealed
using plugs provided by the manufacturer.
Power (kW)
M12
M16
M16
M20
M25
M25
1 1
2 2
3 3
4 4
WILO SE 04/2020