Wilo MVIL Serie Instrucciones De Instalación Y Funcionamiento página 14

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Dry-running protection
To ensure that the pump is always primed,we
recommend to protect it with a pressure switch
or a float switch.
6.3 Check the motor sense of rotation
- With an open-end screwdriver placed in the slot
of the shaft on fan side,make sure that the pump
turns freely without sticking.
Three-phase motor
- Switch on the motor by short pressing on the
motor-overload release and check that it turns in
the direction indicated by the arrow located on
the identification label of the pump.
- In the opposite case and if the motor had three
phase, cross two phase wires on motor terminal
block or on the switch.
Single-phase motor
The single-phase motors and motors variatiors
are designed for operating in the correct sense
of rotation.
The sense of rotation is adjusted when assem-
bling the product and is independent from the
network connection.
6.4 Starting
WARNING! Depending on conveyed fluid and
running of pump, surface temperature can
exceed 68°C. Take necessary means to avoid
injuries.
CAUTION! The pump must not operate at zero
flow (closed discharge valve) for more than 10
minutes with cold water (T° C < 40° C) and more
than 5 minutes above 60° C.
We recommend to ensure a minimum flow of
about 10 % of the nominal flow of the pump to
avoid the formation of a vapour lock at the top
of the pump.
- Keep the discharge valve closed.
- Start the pump.
- Open draining plug to drain air. If no water leaks
within 20', close the plug and stop the pump,
then wait 20' to allow air to settle.
- Start again the pump.
- If necessary (particularly if the suction height
exceeds 5 m) repeat these operations.
- If water leaks at draining plug (it means the
pump delivers its pressure), slowly open the dis-
charge valve. The pump has to be primed.
- Check pressure stability at discharge with a
manometer, if instability, perfect air draining.
- In case of failure, do the filling in again and start
the operation again.
- To perfect air draining, close the discharge valve
and the draining plug, then stop the pump 20',
start the pump again and open the draining plug.
Do it as long as air comes out.
- Open the discharge valve in order to have the
wished working point.
- Check that the current input does not exceed
the value indicated on the motor data plate.
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7. Maintenance
DANGER! Before any operation, switch off the
pump(s).
No special maintenance in operation.
Keep the pump and the motor perfectly clean.
In case of prolonged stopping, if there is no risk
of frost, it is best not to drain the pump.
The bearing holding the coupling is lubricated
for its total lifetime and does not require any
lubrication.
Motors
The bearings are lubricated for their lifetime and
do not require any lubrication.
Mechanical seals
The mechanical seal does not require any main-
tenance in operation.
It must never operate dry.
Replacement frequencies
The replacement frequency of the mechanical
seal depends on the operating conditions of the
pump:
- Temperature and pressure of the conveyed fluid
for the mechanical seal.
- Starting frequency: continuous or intermittent
running.
The replacement frequency of the other com-
ponents depends on the operating conditions of
the pump like load and ambient temperature.
WILO SE 04/2019