Assembly And Installation; Electrical Installation; Operation With Frequency Converter; Commissioning - Wilo Economy-MHI 2 Serie Instrucciones De Instalación Y Funcionamiento

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5. Assembly and Installation

5.1 Installation
Fig. 2 shows a typical pump installation. Installation and assembly
instructions, which must be observed with this type of operation, are
listed as follows:
– Before installing the pump, make sure that all welding and soldering
on the pipe system has been completed and that the pipe system
has been completely flushed out. Foreign bodies and dirt will dama-
ge the pump.
– Install the pump in a dry place free of frost.
– Leave room for maintenance work to be carried out.
– The motor ventilator inlet must be kept clear, at least 0.30 m from
the wall to the rear.
– Install in a horizontal and flat position.
– The pump must be held in place with two 8 mm diameter screws,
on a vibration-absorbing base. Commercially available rubber-metal
connectors can also be used to hold it in place and absorb vibra-
tions.
– To ensure that the drain valve can be accessed, the pump must be
installed with the drain valve at least 20 mm above the floor.
– Isolating valves (1) should be installed in front of and behind the
pump, so that the pump can be easily changed and/or maintenance
work can be carried out more easily.
– A backflow preventer (2) should be installed immediately behind the
outlet pressure gland of the pump.
– The inlet and outlet pipes should be connected to the pump without
stress. Flexible lengths of pipe or bellow expansion joints of
restricted length can be used to ensure a low-vibration connection.
The weight of the pipework must be supported.
– The customer should take suitable measures to prevent low water
levels and hence guard against the pump running dry in order to
protect the axial face seal. The WILO range comprises various
accessories which can be used for this purpose.
– The customer should protect the pump at the inlet pipe with a
strainer (1mm mesh) or filter connection (5) to avoid the pipe
being damaged by any dirt which may be sucked in.

5.2 Electrical installation

– Electrical work must be carried out by a qualified and
licensed electrician in strict compliance with local regu-
lations.
– The electricity supply must be connected via a rigid supply cable
fitted with a coupler or an all-pole switch with a contact gap of at
least 3 mm in accordance with the local regulations in force (e.g. in
accordance with the latest edition of IEE wiring regulations).
– Check the mains current and voltage.
– Ensure compliance with the data on the pump rating plate.
– 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.
AC 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 external 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 for rotary or alternating current 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.
10

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 û > 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 filter 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.
WARNING!
The pump must not run dry, as this would destroy
the axial face 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 rotary current motors): Check
that the pump rotates in the 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 pump terminal box.
– Only for rotary current motors: Adjust the motor cut-out to the nomi-
nal current given on the rating plate.
– If available, position float switches or electrodes 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 pumped fluid comes out, close the vent screw,
open the isolating valve at the outlet and switch on the pump.
– Depending on the fluid temperature and the system pres-
sure, if the vent screw is completely loosened hot liquid or
gas can escape or even shoot out at high pressure.
Beware of scalding.
– Depending on the operating conditions of the pump or
installation (fluid temperature), the entire pump may be-
come very hot.
Avoid touching the pipe owing to the risk of burning.
WARNING! The pump must not run for longer than 10 minutes
with a flow rate of Q = 0 m
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
axial face seal. Should a more significant leak occur as a result of
substantial wear, have the axial face 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.
– 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.
≤ n ≤ 100%n
.
nom nom
3
/h. We recommend that