Inhaltsverzeichnis
Werbung
Verfügbare Sprachen
Verfügbare Sprachen
Use and installation instruction manual
The direction of rotation must be checked by observing the motor on the cooling
fan side. Do not remove the protection devices to check the direction of rotation.
While checking the direction of rotation, run the motor for as short a time as
possible. If the direction of rotation cannot be visually checked, it is possible to
check it indirectly by installing the pump in the system and running it at maximum
flow rate (valves completely open, free delivery), according to one of the two
following modes:
• During operation, measure the maximum power consumption with an
ammeter clamp. If the direction of rotation is incorrect, the values will be nearly
double those specified on the rating plate.
• Alternatively, run the machine for a few seconds, then reverse the direction of
rotation and repeat the operation. The correct direction is the one in which the
greatest flow rate is obtained.
To reverse the direction of rotation, it is sufficient to swap two phases between
them.
4.4 Variable frequency drive (VFD) applications
For variable frequency installations (power supply via "inverter"), make sure the
frequency inverter can supply the rated voltage and at least 10% more current
than the rated value shown on the motor rating plate. To install and connect the
device, please refer to the manufacturer's instruction manual.
5 HYDRAULIC CONNECTIONS
Before starting any work on the electric pump or the motor, make sure
that the power supply is disconnected, and it cannot be accidentally
restored.
Installing the electric pump can be complex and dangerous for people.
This operation must, therefore, be performed by competent, qualified
installers.
Refer to Fig. A5-A or A5-B in the appendix as the case may be. The pipe diameter
determines the flow rate and pressure available at the points of use. Small
diameter pipes increase noise, reduce performance and increase water hammers
and the risk of cavitation. Adopt larger flow cross-sections the longer the pipe
length, possibly with a larger diameter than that of the hydraulic connections of
the appliance. In this case, any diameter reductions along the horizontal sections
must be made with asymmetrical fittings (detail 6 in fig. A5), to facilitate air
escape. For the same reason, a pipe angle (about 3 cm/m, detail C in the figure)
of at least 2° is recommended in the direction of flow. If the electric pump extracts
from a non-pressurised line (e.g. a well or a tank, at a higher height than that of
the exposed surface) it is necessary to install a foot or non-return valve along the
suction pipe to prime the pump (3 in fig. A5). A mechanical filter may also be
necessary to protect the pump. The depth of the suction pipe must be sufficient to
prevent air from entering (detail 7 in fig. A5). For installations on pressurised lines
or negative suction head ones, also install a non-return valve before or after the
pump (5 in fig. A5) - to avoid emptying the delivery pipe following the shutdown
of the electric pump, and to avoid backflow - as well as a filter. If the machine is
connected to a closed hydraulic circuit, installing one or more vent valves at the
highest points of the circuit is recommended. Secure the pipes to the flanges of
the pump, without damaging them. Pay attention to the suction line pressure
which can be lower than the atmospheric one (risk of air entering through joints).
Make sure that the misalignment between pipes and outlets does not generate
an excessive load on the pump flanges. The force and momentum threshold
values on the connections are shown in figure A9, depending on the model. It
is recommended to install a flexible element on each side (2 in fig. A5), also in
order to limit the transmission of vibrations. The electric pump can be installed
with a pipe made of either metal or another material, provided it is mechanically
rigid and resistant to even the maximum operating temperature. Pipes must be
properly supported so as not to burden the pump flanges (detail 1 in fig. A5) and
must remain in position even with no pump. Install shut-off valves upstream and
downstream of the pump, to simplify maintenance operations (4 and 8 in fig. A5).
5.1 Checking the NPSH
Check the electric pump characteristic curves to evaluate the NPSH factor (see
Fig. A6) and thus prevent cavitation problems in case of a difference in height
between the pump and the level of the liquid to be drawn or for excessively high
temperature. The maximum height of the pump from the liquid level "H" (see fig.
A7-B) can be calculated with the following formula:
H = pb x 10.2 – NPSH – Hf – Hv – Hs
pb: Absolute barometric pressure or absolute pressure of the liquid on suction
[bar].
NPSH: Suction head at maximum flow rate capacity [m] (fig. A6)
Hf: Pressure drop in the suction pipe at maximum pump flow rate [m]
Hv: Vapour pressure [m] depending on the temperature of the liquid [m] (fig.
A7-A)
Hs: Safety margin [m] (minimum 0.5)
If the calculated value is less than "0", the pump must be positioned below the
liquid level.
Example
pb = 1 bar
Pump type: 10
Flow rate: 9 m
/h
3
NPSH: 1.5 m (see fig A6)
Hf = 2.5 m
Liquid temperature: +50°C
Hv: 1.3 m (see fig. A7-A)
H = pb x 10.2 NPSH-Hf-Hv-Hs [m]. = 1 x 10.2-1.5-2.5-1.3-0.5 = 4.4 [m]
This means that the height of the pump from the level of the liquid to be drawn
must not exceed 4.4 meters
5.2 Maximum pressure check
Operating pressure
The sum of the inflow pressure (p1) and the maximum pressure produced
by the pump must always be lower than the maximum operating pressure
Pmax, indicated on the rating plate.
Case 1: Single standard pump (fig. A8-A)
P1 [bar]+ Hmax [m]/10 <= Pmax [bar]
Case 2: Standard pump + high pressure pump (fig. A8-B)
P1 [bar]+ Hmax,1[m] /10 <= Pmax,1 [bar]
P1 [bar]+ Hmax,1[m] /10 + Hmax,2[m] /10 <= Pmax,2 [bar]
Pressure on suction
The suction pressure must not exceed the limits shown in the tables of (figure A9,
value P1 max).
6 MECHANICAL INSTALLATION
Remove the pump from the packaging and check that it is intact. Also
check whether the rating plate details match the desired ones. In case of any
discrepancies, contact the supplier immediately, specifying the nature of the
defects.
6.1 Machine handling
To lift the machine, use only suitable, properly marked devices in good working
condition. Do not exceed the load capacity of the least resistant device among all
those used (lifting lug, shackle, hook, carabiner, chain, rope, hoist or other). Only
use hooks with safety latch. Use adjustable lifting lugs or check their maximum
load capacity for non-axial loads.
Check the weight of the machine before starting the lifting operations.
The weight is indicated on the rating plate. For pumps sold without
motor, the indicated weight refers only to the pump
The suspension point provided on the pump/electric pump does not
match the machine's centre of mass
During lifting, the machine will tend to rotate around the lifting point until it
reaches a balanced position. Handle with care. Pay attention to the inertia of
the object (oscillations in the direction of travel, difficulty in slowing down and
stopping).
The eyebolts on the motors must only be used to move the motor (see fig.
A10-C).
If the appliance is fitted with lifting eyelets, attach the lifting straps or chains to
the eyelets using lifting hooks or shackles, as shown in fig. (A10-B and F). Follow
the user instructions provided by the manufacturer of the lifting devices. For
pumps not fitted with eyelets, wrap the belts around the pump motor support
(fig. A10-E), taking particular care not to damage the side coupling shield
protections. For electric pumps without eyelets (fig A10-A), strictly follow the
instructions below (see also fig. A10 - from 1 to 4):
1) Wrap the belts around the motor support
2) Bring the appliance to the ground, rotating it around a corner of the base,
controlling the movement by means of lifting equipment and controlling any
sudden overturning with one foot
3) Lay the appliance on the ground
4) Lift it slowly until the appliance reaches a balanced position (with the motor
upwards or downwards, as appropriate).
Pay attention to suspended loads. Do not stand under them. Pay attention
to people, animals and objects in the work area. Use appropriate work
area marking tools and delimiters, where necessary. Do not operate the
pump or let it pass over people.
6.2 Positioning
• Install the electric pump in an accessible location and protected against frost,
leave enough space around the electric pump to allow use and maintenance
operations.
ENGLISH
13
Werbung
Inhaltsverzeichnis
