Electrical Connection; Cable Entry/Screwed Connection; Three-Phase Connection; Single-Phase Connection - Grundfos CRT Serie Instrucciones De Instalación Y Funcionamiento

7. Electrical connection

The electrical connection should be carried out by an authorised
electrician in accordance with local regulations.
Warning
Before removing the terminal box cover and
before removing/dismantling the pump, make
sure that the power supply has been switched off
and that it cannot be accidentally switched on.
The pump must be connected to a main switch.
The user is to consider whether it is necessary to
Caution
install an emergency stop switch.
The operating voltage and frequency are marked on the motor
nameplate. Make sure that the motor is suitable for the power
supply on which it will be used and the motor terminal connection
is correct. You will find a wiring diagram in the terminal box.

7.1 Cable entry/screwed connection

All motors are supplied without screwed cable entries. The table
below shows the numbers and sizes of cable entry holes of the
terminal box (standard: EN 50262).
Motor Number and size
[kW] of cable entries
0.25 - 0.55 2 x M20 x 1.5
0.75 - 3.0 2 x M20
4.0 - 7.5 4 x M25
2 x M20
11 - 18.5
4 x M40

7.2 Three-phase connection

Mains supply [V]
Delta connection
220-240
50 Hz
380-415
220-277
60 Hz
380-480
1)
60 Hz motors, 0.37 - 1.1 kW: 220-277/380-440 V.
W2 U1
W1 U2
V2
V1
Fig. 12 Delta connection
U1
U2
W2
V2
W1
V1
Fig. 13 Star connection
If the motor is provided with PTC sensors or PTO contacts, the
connection must be in accordance with the wiring diagram in the
terminal box.
Three-phase motors must be connected to a motor-protective
circuit breaker.
12
Description
The holes have precast
threads and are closed with
knock-out cable entries
The holes are closed with
knock-out cable entries
The holes are closed with
knock-out cable entries
The holes are closed with
knock-out cable entries
Star connection
/ 380-415
/ 660-690
1)
/ 380-480
/ 660-690
W2 U2 V2
U1 V1 W1
L L L
1 2 3
U2 V2
W2
U1 V1 W1
L L L
1
2 3

7.3 Single-phase connection

Mains supply [V]
"Low voltage"
50 Hz 220-230
Fig. 14 Connection, "low voltage", 0.37 - 0.75 kW
Fig. 15 Connection, "high voltage", 0.37 - 0.75 kW
Fig. 16 Connection, "low voltage", 1.1 - 2.2 kW
Fig. 17 Connection, "high voltage", 1.1 - 2.2 kW
Single-phase Grundfos motors incorporate a thermal switch and
require no additional motor protection.
"High voltage"
/ 240