Electrical Connection - Lowara e-LINE Serie Manual De Instalación, Uso Y Mantenimiento

en - Original instructions
 With valves, when applicable, with a low
specific flow resistance.
10. In the case of suction lift installation, check that
no vortexes can occur at the end of the suction
pipe, at the point of the foot check valve.
11. Install a check valve on the delivery side to
prevent the liquid from flowing back into the pump
unit when this is at standstill.
12. Install a pressure gauge (or a vacuum pressure
gauge, in the case of suction lift installation) on
the suction side, and a pressure gauge on the
delivery side, for checking the actual operating
pressure of the pump unit.
13. To exclude the pump unit from the system for the
purpose of maintenance, install:
 An on-off valve on the suction side
 An on-off valve on the delivery side,
downstream of the check valve and pressure
gauge, useful also for regulating the flow.
14. On the suction side, install a device to prevent the
absence of liquid or a minimum pressure device;
if the liquid is drawn from a tank or basin, install a
float or probes.
4.2.2 Forces and torques for flanges
The maximum allowable forces and torques applied by
the pipes on the flanges of the pump unit are given in:
 Tab. 9, anchoring directly on the pipes
 Tab. 10, anchoring on the concrete foundation.
The data are valid for:
 Single-impeller and double volute pump units
 EN-GJL-250 pump units with cast iron body
 Suction side (DNS) and delivery side (DND).
4.3

Electrical connection

DANGER: Electrical hazard
 The connection to the electric power supply
must be completed by an electrician
possessing the technical-professional
requirements outlined in the current
regulations
 Before starting work, check that the unit is
unplugged and that the pump unit, the
control panel and the auxiliary control
circuit cannot restart, even unintentionally.
4.3.1 Grounding (earthing)
DANGER: Electrical hazard
 Always connect the external protection
conductor to the ground terminal before
attempting to make any other electrical
connections
 Connect all the electrical accessories of the
pump unit and motor to the ground
 Check that the protection conductor
(ground) is longer than the phase
conductors; in case of accidental
disconnection of the power supply
conductor, the protection conductor
(ground) must be the last one to detach
20
itself from the terminal
 Install suitable systems for protection
against indirect contact, in order to prevent
lethal electric shocks.
4.3.2 Guidelines for electrical
connection
1. Check that the electrical leads are protected
against:
 High temperature
 Vibrations
 Collisions.
2. Check that the power supply line is provided with:
 A short circuit protection device of appropriate
size
 A mains isolator switch with a contact gap of at
least 3 mm.
4.3.3 Guidelines for the control panel
NOTICE:
The control panel must match the ratings of
the pump unit on the data plate. Improper
combinations could compromise the
protection of the motor.
1. The control panel must protect the motor
overloading and short circuits; install suitable
protection (thermal relay or overload cut-out
switch, see table).
Pump unit Protection
 Automatic reset thermal-
Single phase
standard ≤ 2.2
amperometric protection, in-built
kW
(motor protector)
 Short circuit, must be supplied by
the installer.
11
 Thermal, must be supplied by the
Three-phase
installer
 Short circuit, must be supplied by
the installer.
2. Equip the control panel with a system for
protection against dry running to which a
pressure switch (or float switch or sensors or
other suitable devices) must be connected.
3. Install these devices on the suction side:
 A pressure switch, in the case of connection to
the mains water supply
 A float switch or probes, in the case of liquid
drawn from a tank or basin.
4. When thermal relays are used, the type sensitive
to phase failure is recommended.
9
Or, frequency converter plus motor
10
Fuses aM (motor starting), or magneto-thermal
switch with curve C and Icn ≥ 4.5 kA or other
equivalent device
11
Overload thermal relay with trip class 10 A + fuses
aM (motor starting) or motor protection magneto-
thermal switch with starting class 10 A
9
against
10