Operation With Frequency Converter - Wilo Economy-MHI Instrucciones De Instalación Y Funcionamiento

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• Make sure the pump is earthed.
• Mains fuse: 10A time-lag fuse.
• The customer should fit rotary current motors with
a motor safety switch which should be adjusted to
the nominal current given on the rating plate to
prevent the motor from overheating.
Single-phase motors are fitted with a thermal
motor cut-out in the factory. This cuts off the
pump when the permissible temperature of the
motor coil is exceeded and switches it back on
again automatically once it has cooled down.
• A supply cable with an adequate ample exter-
nal diameter (e.g. 05 VV-F 3/5 G 1.5 or AVMH-I
3/5x1.5) should be used to protect against damp
and to secure the mains lead cleat of the stuffing
box.
• Connection to the mains must be carried out in
accordance with the plan of terminal connections
in the terminal box of the pump (see also Fig. 4).
• Heat-resistant cable must be used if the pump is
fitted in installa tions in which the temperature of
the fluids pumped exceeds 90 °C.
• The supply cable must be laid in such a way that
it never touches the pipework and/or the pump
and motor casing.
If necessary a fault current breaker (FI-switch)
should be provided.

5.3 Operation with frequency converter

The speed of the pump can be controlled when
connected to a frequency converter.
Speed control limits: 40%n
See Installation and operating instructions of the
frequency converter for connection and operation.
To avoid overloading the motor coil to the extent
that it is damaged and to avoid increasing noise
levels, the frequency converter must not produce
speeds due to increased voltage of over 500 V/
µs and spikes of > 650 V. If such speeds due to
increased voltage are possible, an LC filter (motor
filter) should be installed between the frequency
converter and the motor. The layout of the fil-
ter must be designed by the manufacturer of the
frequency converter or filter.
In control devices with frequency converters
supplied by Wilo, the filter is already installed.
6. Commissioning
• Check that there is a sufficient level of water in
the reservoir and/or check the inlet pressure.
The pump must not run dry, as this would destroy
the mechanical seal.
• 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.
• Checking direction of rotation (only for three-
phase motors): Check that the pump rotates in
the direction indicated by the arrow on the pump
rating plate by switching on for a short time. If
this is not the case, interchange 2 phases in the
pump terminal box.
• Only for three-phase motors: adjust the motor
cut-out to the nominal current given on the ra-
ting plate.
• If available, position float switches or electrodes
16
≤ n ≤ 100%n .
nom nom
for protection against low water levels in such a
way that the pump cuts out if the water level is
so low that air would begin to be sucked in.
• Open the isolating valve at the inlet, open the
vent screw (Figs 1 & 2, 3, SW 19) until the pum-
ped fluid comes out, close the vent screw, open
the isolating valve at the outlet and switch on the
pump.
WARNING! Beware of scalding!
Depending on the fluid temperature and the sys-
tem pressure, if the vent screw is completely loo-
sened hot fluid or gas can escape or even shoot
out at high pressure.
WARNING! Avoid touching the pipe owing to
the risk of burning!
Depending on the operating conditions of the
pump or installation (fluid temperature), the
entire pump may be come very hot.
The pump must not run for longer than 10 minu-
tes with a flow rate of Q = 0 m
that when running continuously the pump should
be kept at a minimal flow of 10% nominal flow.
7. Maintenance
• The pump is almost maintenance free.
• During the running-in period, there may be some
dripping from the mechanical seal. Should a more
significant leak occur as a result of substantial
wear, have the mechanical seal replaced by a
specialist.
• Increased bearing noise and unusual vibrations
indicate a worn bearing. In this case, have the be-
aring replaced by a specialist.
• Before carrying out any maintenance work,
switch off the pump and ensure that it cannot be
switched on again by unauthorized people. Never
carry out work on a running pump.
• When the pump is exposed to frost or is out of
service for a long period, the pump and pipework
must be emptied in the cold season. Empty the
pump by releasing the drain valve (Figs 1 & 2, 4),
the inlet pipe by releasing the vent screw, and
the outlet pipe by opening the bleeding point.
/h. We recommend
3
WILO SE 10/2017