Piping Requirements; Electrical Requirements - Lowara ESH Serie Manual De Instalación, Funcionamiento Y Mantenimiento

• Temperature of the liquid
• Elevation above the sea level (in an open sys-
tem)
• System pressure (in a closed system)
• Resistance of the pipes
• Own intrinsic flow resistance of the pump
• Height differences
The following equation is used to calculate the maxi-
mum height above the liquid level which the pump
can be installed:
(p *10.2 - Z) ≥ NPSH + H
b
p Barometric pressure in bar (in closed sys-
b
tem is system pressure)
NPSH Value in meter of the pump intrinsic flow re-
sistance
H Total losses in meters caused by passage of
f
liquid in the suction pipe of the pump
H Steam pressure in meters that correspond
v
to the temperature of the liquid T °C
0.5 Recommended safety margin (m)
Z Maximum height at which the pump can be
installed (m)
(p *10.2 - Z) must always be a positive number.
b
For more information, see
NOTICE:
Do not exceed the pumps suction capacity as this
could cause cavitation and damage the pump.

4.1.2 Piping requirements

Precautions
WARNING:
• Use pipes suited to the maximum
working pressure of the pump. Fail-
ure to do so can cause the system to
rupture, with the risk of injury.
• Make sure that all connections are
performed by qualified installation
technicians and in compliance with
the regulations in force.
NOTICE:
Observe all regulations issued by authorities having
jurisdiction and by companies managing the public
water supplies if the pump is connected to a public
water system. If required, install appropriate back-
flow-prevention device on the suction side.
Piping checklist
Check that the following requirements are met:
• All piping is independently supported, piping
must not place a burden on the unit.
• Flexible pipes or unions are used, in order to
avoid transmission of pump vibrations to the
pipes and vice versa.
• Use wide bends, avoid using elbows which
cause excessive flow resistance.
• The suction piping is perfectly sealed and air-
tight.
• If the pump is used in an open circuit, then the di-
ameter of the suction pipe is suited to the instal-
+ H + 0.5
f v
Figure 12 on page 375.
lation conditions. The suction pipe must not be
smaller than the diameter of the suction port.
• If the suction piping must be larger than the suc-
tion side of the pump, then an eccentric pipe re-
ducer is installed.
• If the pump is placed above liquid level, a foot
valve is installed at the end of the suction piping.
• The foot valve is fully immersed into the liquid so
that air cannot enter through the suction vortex,
when the liquid is at the minimum level and the
pump is installed above the liquid source.
• Appropriately sized on-off valves are installed on
the suction piping and on the delivery piping
(downstream to the check valve) for regulation of
the pump capacity, for pump inspection, and for
maintenance.
• Appropriately sized on-off valve is installed on
the delivery piping (downstream to the check
valve) for regulation of the pump capacity, for
pump inspection, and for maintenance.
• In order to prevent back flow into the pump when
pump is turned off a check valve is installed on
the delivery piping.
WARNING:
Do not use the on-off valve on the dis-
charge side in the closed position in or-
der to throttle the pump for more than a
few seconds. If the pump must operate
with the discharge side closed for more
than a few seconds, a bypass circuit
must be installed to prevent overheating
of the liquid inside the pump.
For illustrations that show the piping requirements,
see Figure 13 on page 376 and
376.

4.2 Electrical requirements

• The local regulations in force overrule these
specified requirements.
• In the case of fire fighting systems (hydrants
and/or sprinklers), check the local regulations in
force.
Electrical connection checklist
Check that the following requirements are met:
• The electrical leads are protected from high tem-
perature, vibrations, and collisions.
• The power supply line is provided with:
– A short-circuit protection device
– A mains isolator switch with a contact gap of
at least 3 mm
The electrical control panel checklist
NOTICE:
The control panel must match the ratings of the elec-
tric pump. Improper combinations could fail to guar-
antee the protection of the motor.
Check that the following requirements are met:
• The control panel must protect the motor against
overload and short-circuit.
• Install the correct overload protection (thermal re-
lay or motor protector).
en - Original instructions
Figure 14 on page
19