Wilo COHe, Installation And Operating Instructions Manual

Page: 20 / 28

p. 20 4227862 ed.04
- The type of current and voltage of the mains connection must comply with the details on the type plate and
the circuit diagram of the control box.
- The electrical connecting cable must be adequately dimensioned according to the total power of the booster
(see type plate).
- As a protection measure, the booster must be earthed according to the rules (i.e according to the local
regulations and circumstances). The connections intended for this purpose are identified according (see circuit
diagram).
- The base frame has to be connected to earth by using an earth braid linked to the frame (
Pos.11, Fig 1.a
).
8 Commissioning
We recommend that the booster is first commissioned by nearest
WILO
customer service agent or ask your
central customer service department.
8.1 General preparation and checking
-
Before switching on for the first time, check the wiring has been done correctly on site,
particularly the earthing.
-
Check that the pipe connections are stress-free.
-
Open the shut-off valves on the pumps and in the suction and discharge manifold.
-
Fill the installation and check visually for leaks.
-
Open the pump vent screws to remove air.
-
Slowly fill the pumps with water (suction condition only).
ATTENTION !
Do not allow the pump to run dry. Dry running destroys the mechanical seal.
-
Dry running protection:
 With public water mains connection: pressure switch to be connected to the booster.
 In the tank, position the float switch for low water protection so that the booster switches
off at minimum water level, 10 cm minimum above the bleed screw of the pump.
WARNING! Electrical shock hazard!
Switch off the installation main switch before changing over the phases!
-
Check the direction of rotation of the pumps: switch on briefly and check whether the direction
of the pumps corresponds to the arrow on the pump label. Change over 2 phases if the
direction of rotation is not correct.
-
Check the motor heat protections inside the control box are set for the right nominal current.
See the manual leaflet of the control box.
-
On the control box check and set the operating parameters required according to the attached
installation and operating instruction.
8.2 Commissioning the installation
After all preparations and checks according to section 8.1 have been done, switch on the main switch and set
the control system to the automatic mode. The pressure sensor measures the pressure and transmits a
corresponding current signal to the control box. If the pressure is lower than the preset starting pressure, it
then switches on the base load pump first of all (according to the preset parameters and type of setting) and
then the peak load pumps if necessary until the pipes are filled with water and the set pressure has built up.