Electrical Connection - ITT Lowara Instrucciones Para La Instalación Y El Uso

en
6.1.1 Checking the oil level
Check the oil level in the mechanical seals chamber following the instructions provided in section 7.2.1.
6.1.2 Checking the cable gland for the power supply cable/s
Make sure the cable gland is fastened tightly, according to the instructions provided in section 7.2.2.
6.1.3 Checking the rotation of the impeller
Make sure that the impeller rotates freely; follow the instructions provided in section 7.2.3.
6.1.4 Connections
Refer to the diagrams in section 10.5.
6.2

Electrical connection

The electrical connections must be performed by a qualified installation technician in compliance with the
regulations in force.
Make sure that the supply voltages and frequencies are suited to the characteristics of the electric motor.
WARNING
Refer to the electric pumps' rating plates.
Provide suitable general protection against short circuits on the power line.
Before proceeding, make sure that all the connections (even those that are potential-free) are voltage-
free.
The power supply line must be provided with the following devices (unless otherwise specified by the
local regulations in force):
• A short-circuit protection device
• A high-sensitivity differential device (30mA) providing additional protection against electric shock in
• A mains isolator switch with a contact gap of at least 3 millimeters.
Ground the system according to the regulations in force. This is the first electrical connection to be
performed. Protect the electrical conductors from too high temperatures, vibrations and collisions.
For connection of the power supply cable, refer to the diagrams in section 10.6.
Some electric pumps may be equipped with a thermal sensor in the motor, and/or a sensor designed to detect the presence of
water in the oil chamber. Observe the number marked on the cable sheath or the colour of the sheaths.
6.2.1 Overload protection
The user must provide the overload protection (thermal relay or motor protector).
WARNING
Adjust the thermal relay or motor protector to the nominal current value of the electric pump or to the operating current in case
the motor is not used at full load. If the motor has a star-delta starting system, adjust the thermal relay to a value equal to 58%
of the nominal current or operating current.
Refer to section 5.1.3 for information regarding the electric panel.
6.2.2 Protection against dry running
Refer to sections 5.1.3 and 5.1.4.
6.2.3 Direction of rotation
Reverse rotation may cause damage to the motor and the mechanical seal.
WARNING
The correct direction of rotation is indicated by arrows on the pump body and/or motor casing.
After making the electrical connection ( section 6.2), check that the direction of rotation is correct using one of the following
methods:
- Place the electric pump in the horizontal position and remove the suction elbow, if present. Start the electric pump and let it
run for a few seconds, checking the direction of rotation through the suction port. It must rotate counter-clockwise (in the
direction indicated by the arrow on the pump body).
Do not insert hands, other body parts or tools into the suction port.
- Suspend the pump in vertical position. Start the electric pump and let it run for a few seconds, checking that the kick back on
start-up causes the pump to rotate slightly counter-clockwise when looked at from above the motor (opposite direction from
that of the arrow on the pump body)
Stand away from the pump, as the kick back could be quite violent.
If the rotation direction is incorrect, stop the pump, disconnect the power supply and exchange the position of two phase
conductors in electric panel's terminal board, if the pump is a three-phase model, or check all the connections if the pump is a
single-phase model.
6.3 Operation
Normal operation requires the use of floats to control the starting and stopping of the electric pump.
Check the current absorbed by the motor and, if necessary, adjust the setting of the thermal relay.
WARNING
Make sure that the level of the liquid is high enough to prevent inlet of air to the pump through the
suction port.
18
case the grounding system is inefficient.