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2.3.5.6. Electrical Connections
The electrical motors have to be built in accordance with EN 60034-1.
Enclosures of electrical motors and control systems on the pump unit shall as a minimum give protection
in accordance with EN 60529 IP22. But in determining the degree of protection of enclosures of electrical
motors and control systems on the pump unit the operating and environmental conditions must be taken into
consideration.
Electrical connection should be done by a qualified electrician. Current national regulation and motor manufacturer's
instructions must be observed.
Take all safety precautions listed in "Safety Instructions". Disconnect all power supplies prior to doing any work.
The supply cable must be laid in such a way that it never touches the pipework, pump and motor casing.
Check voltage, phase and frequency on motor nameplate with the mains.
The electric motor must be protected against overloading by means of circuit breakers and/or fuses. Circuit breakers
and fuses must be selected in accordance with full load amperage of the motor appearing on the motor rating plate.
It is recommended to use PTC (Passive Thermal Control) on motor, but this is optional depending on customer
requirement. In case of using PTC, these should be connected via corresponding terminals in the terminal box and
the PTC should be connected to the thermal trip mechanism.
Prior to connecting the electrical wiring rotate the pump shaft by hand to make sure rotor rotates easily.
Connect the electrical wiring in accordance with local electrical codes and make sure to ground the motor.
The connection diagram can be found in the terminal box of the motor or in the instruction manual.
The mains connection on the tagboard depends on the nominal power of the motor, the power supply and the type
of connection. The necessary connection of the bridges in the terminal box is shown in the following (Table 1. and
Fig. 12a, 12b, 12c).
Type of switch
Direct
Y / ∆ - start
.
Fig. 12a
∆ - connection
Motor Power
��
≤ 4 ����
��
Power supply
3 ≈ 400 V
Y – connection (10b)
Impossible
Table 2
Fig. 12b. Y – connection
17
Motor Power
��
> 4 ����
��
Power supply
3 ≈ 400 V
∆ - connection (10a)
Remove connecting
Bridges (10c)
Fig. 12c. Y / ∆ connection
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