Operation With Frequency Converter - Wilo MultiVert MVI 16 Série Notice De Montage Et De Mise En Service

supply line in phase (U1/V1/W1 or U2/V2/W2),
then the motor safety switch should be adjusted
to the value of 0.58 of the nominal motor current.
• The mains cable can be inserted to the left or the
right of the terminal box. Open the appropriate
hole by removing the moulded cover, unscrew
the PG connector and push the cable through the
PG connector.
• The supply cable must be protected against the
effects of heat and vibrations which may come
from the motor or the pump.
• When using the pump in machinery where the
water temperature exceeds 90°C, a connecting
pipe with corresponding heat resistance must
be used.
• Connections to the mains must be carried out in
accordance with the plan of terminal connections
for rotary or alternating current in the terminal
box of the pump (Fig. 4).
• The terminal box can be better positioned by
rotating the motor through steps of 90°. To this
end the connecting screws (Fig. 1, Pos. 1) of the
lantern (Fig. 1, Pos. 8) and motor flange are to
be loosened.
In the case of internal connecting screws the
clutch guard (Fig. 1, Pos. 2) is to be removed
beforehand. When assembling the clutch guard,
do not forget to tighten the safety screw.

5.3 Operation with frequency converter

The speed of the pump can be controlled when
connected to a frequency converter.
See Installation and Operating Instructions of the
frequency converter for connection and operation.
The frequency converter may not generate a speed
due to increased voltage greater than 2500 V/µs
and voltage peaks û > 1000 V, as otherwise the
motor coil will be destroyed. If such speeds due to
the increased voltage are possible, an LC filter
(motor filter) should be installed between the
frequency converter and the motor.
6. Commissioning
-
In order to protect the axial face
WARNING!
seal, the pump must not run dry.
• Close both isolating valves and open the vent
screw (Fig. 2, 5) by one and a half or two turns.
• Slowly open the isolating valve (Fig. 2, 2) at the
inlet until the air has escaped from the vent
screw and the fluid to be pumped comes out. The
escaping air will be clearly heard hissing. Tighten
the vent screw.
• Slowly open the isolating valve at the outlet (Fig. 2,
3). The mano-meter installed at the outlet should
be checked for any possible pressure instabilities,
indicated by a flickering manometer pointer. If the
pressure is unstable, allow more air to escape.
When the temperature of the liquid being
pumped is high and the system is pressurised,
any flow escaping from the vent screw can cause
scalding and injuries. The vent screw should
therefore be loosen only slightly.
• When used for the first time, if it is to be used to
pump drinking water the system must be flushed
through, so that any dirty water present will not
contaminate the drinking water supply.
WILO SE 11/2010
• Checking the direction of rotation (only for
rotary current motors): Check that the pump
rotates in the same direction indicated by the
arrow on the pump casing by switching on for a
short time. If this is not the case, interchange
2 phases in the terminal box.
For pumps with a star or triangular circuit starting
current, the connections of two coils must be
interchanged, e.g. U1 with V1 and U2 with V2.
• If the fluid temperature is too high, steam may
form which may damage the pump. The pump
must therefore not run with the valve closed for
longer than 10 minutes when pumping cold
water or for longer than five minutes when
pumping fluid where > 60°C.
We recommend that the flow rate does not drop
to below 10% of the nominal flow rate so as to
avoid a build up of steam in the pump.
• If there is a build up of steam, this should be al-
lowed to escape by carefully opening the vent
screw.
Both pump and motor can reach operating
temperatures > 100°C. Therefore exercise caution
when touching the pump.
7. Maintenance
Before carrying out any maintenance work, switch
off the pump and ensure that it cannot be
switched on again by unauthorised people. Never
carry out work on a running pump.
• During the running-in period, there may be some
dripping from the axial face seal. In the event of a
serious leak as a result of heavy wear have the
mechanical seal replaced by a specialist.
• Increased bearing noise and unusual vibrations
indicate a worn bearing. In this case, have the
bearing replaced by a specialist.
• If the pump is exposed to frost, the pump and
pipework must be emptied in the cold season.
Close the isolating valve and open the drain valve
(Fig. 2, 6) and the vent screw (Fig. 2, 5) of the
pump.
The isolating valve must be closed before the drain
valve is opened.
Type < 22 kW 22 kW
MVI 16
MVI 32
MVI 52
MVI 70
MVI 95
English
30 kW 37 kW 45 kW
5