Installation And Preparation - E-Tech EM 3 Manual De Uso

Operating and installation manual
on altitude or temperature (see Fig. 6).
4.2.3 Maximum number of motor start-ups
The table shows the maximum number of start-ups per hour for the electric pumps
supplied with a standard motor.
Power (kW)
2 poles
60
0,37-0,55
60
0,75-3
30
4-7,5
4.3 Pump data plate
The data plate, positioned on the side of the pump's outer casing, contains the main
information about the machine (Fig. 9-T).
Single phase models:
A) Electropumps model
B) Serial number
C) Date of manufacture
D) Product code
E) Working capacity range
F) Head range
G) Minimum head (as per EN 60335-2-41)
H) Head at 0 capacity
I) Type of motor and functioning frequency
L) Maximum absorbed power
M) Electrical connections/data of motor
N) Maximum ambient temperature
O) Motor efficiency class
P) Insulation class of motor,
Q) Motor IP rating,
R) Weight of electric pump
S) Electrical data capacitor (single-phase motors)
T) Maximum pressure of liquid
U) Maximum operating temperature of liquid (for uses as per EN 60335-2-41)
V) Motor efficiency
4.4 Other plates
A label on the outer case of the pump (see fig. 9-U)
the pump is suitable for handling liquid at 110°C only for industrial use (uses
other than those covered by CEI EN standard 60335-2-41);
Tmax 110°C
the pump is suitable for handling liquid at 90°C for domestic use (uses covered
by CEI EN standard 60335-2-41);
Tmax 90°C
read the instruction manual carefully before use.
A WRAS label on the pump indicates the product can be used for handling
drinking water for human use.

5 INSTALLATION AND PREPARATION

For the pump to function correctly and to avoid damage to people or things, some basic
conditions must be observed. In particular the NPSH and maximum pressure must be
checked.
5.1 Checking the NPSH
Check the characteristic curves of the electric pump to evaluate the NPSH factor (see
Fig. 3) and thus avoid cavitation problems in the case of an excessively high gap
between the pump and the level of the liquid to be drawn or due to an excessively high
temperature (Fig. 4).
The maximum height between the pump and the level of liquid "H" can be calculated
using the following formula:
H = pb x 10.2 – NPSH - Hf - Hv – Hs
pb: Bar pressure or liquid suction pressure [bar].
NPSH: Net positive suction head [m] (see fig.3)
Hf: Friction and entrance head losses in the suction piping [m]
Hv: Steam pressure [m] in relation to the temperature of the liquid (tm) (see fig.4.A)
Hs: Safety margin [m] (minimum 0.5)
If the value calculated is less than "0" the pump should be placed below the liquid level.
Starts for hour
4 poles
140
140
60
Three phase models
Example
bp = 1 bar
Type of pump: EM 9
Capacity: 9 m3/h
NPSH: 1.5 m
Hf = 2.5 m
Liquid temperature: +50°C
Hv: 1.3 m
H = bp x 10.2 - NPSH - Hf - Hv - Hs [m].
H = 1 x 10.2 – 1.5 – 2.5 – 1.3 – 0.5 = 4.4 [m]
This means that the maximum height between the pump and the level of the liquid to
be sucked is 4.4 metres.
5.2 Verifying maximum pressure
Working pressure
It is important to keep the sum of the inlet pressure plus the maximum pressure of the
pump at zero capacity, always lower than the maximum allowed working pressure (PN).
The PN maximum working pressure is shown on the data plate.
5.3 Minimum rated capacity
WARNING: The pump must never operate dry (without liquid inside it).
WARNING: The pump must never operate with the discharge valve closed
for more than 5 seconds.
Functioning for a long time at a lower level than the minimum allowed on the data plate
may cause excessive and dangerous overheating of the pump.
For water temperatures over 40°C, the minimum capacity should be increased
according to the temperature of the liquid (see Fig. 5). For liquids other than water
contact the sales and service office.
5.4 Installation of the pump
WARNING: Please observe current accident prevention standards, use
suitable protective devices and refer to the regulations, legislation and local
and/or national laws in the country of installation regarding water and electricity
connection.
WARNING: DO NOT USE THIS PUMP IN ENVIRONMENTS THAT MAY
CONTAIN INFLAMMABLE/EXPLOSIVE OR CHEMICALLY AGGRESSIVE
POWDERS OR GASES.
WARNING: Installing an electric pump may be a rather complex operation.
It should therefore be carried out by skilled and authorised installers.
5.4.1 Assembly
Guide lines
• Install the electric pump in an accessible area, protected from rain, sun and frost,
leaving sufficient space around the electric pump to allow for its operation and
maintenance.
• Horizontal assembly is permitted only if the electric pump is properly supported.
Vertical assembly is not permitted with the motor placed on the lower part (see fig.9-V).
• Check that there are no obstacles blocking the air flow to cool the motor, make sure
there is at least 100 mm of space in front of the fan (Fig.9).
• Any liquid leakages or similar events must be drained and should not flood the place
of installation and/or submerge the unit.
• The electric pump must ALWAYS be firmly fixed to a concrete base or to a metal
structure of size and weight to suit the size and weight of the electric pump; use
screws suitable for the fixing holes provided (see fig.8 dimensions, tightening
torques). To reduce vibrations to a minimum, insert vibration-damping seals between
the pumps and the base.
• Make sure the pump is correctly orientated: The flow arrows shown on the pump
should point in the direction of flow of the connection pipes.
• The connection pipes must be suitable for the operating pressure and the pumped
liquid; between the pipe connections and the pump proper seals should be inserted.
• The pipes should be properly supported (fig.9-1), without resting on the unit. Do
not force the position of the pipes by fixing them, using bolts, to the pump (see fig.
13 for maximum forces and stresses applicable to connections). Flexible hoses or
expansion joints (fig.9-2) are necessary to avoid vibrations being transmitted from
the pump to the piping and vice-versa.
To prevent air bubbles in the suction pipe, arrange it at an inclination of no less than
2%. The diameter of the pipe should not be smaller than the diameter of the suction
vent and should be sealed. If the suction pipe is bigger, install an eccentric reducer
(fig.9-6). If the pump is above the liquid to be sucked (negative suction head pump
fig.9-A) a foot valve should be fitted to the end of the suction pipe (fig.9-3).
• The end of the suction pipe should be sufficiently immersed to prevent air entering
the suction vortex (fig.9-7) when the liquid is at minimum level. Suitably sized gate
valves should be fitted to the suction pipes (fig.9-4) and delivery pipes (fig.9-8) to
regulate flow and to isolate the pump from the circuit in the case of inspection and
maintenance.
• Install a check valve (fig.9-5) to the delivery piping to prevent reflux and water
hammers when the pump is switched off.
• See fig.7 e 8: pump connections size
WARNING: Depending on the temperature of the pumped liquid, the surfaces
of the electric pump can become very hot. If deemed necessary, provide guards
to avoid accidental contact.
5.4.2 Electrical connections
WARNING: Low voltage machines are made up of rotating, hazardous, live
parts and also sometimes of hot surfaces.
ENGLISH
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