Grundfos TP - Electrical Connection; Frequency Converter Operation

TM028514
Motors with condensation cover
4.4 Electrical connection
Make the electrical connection in accordance with
local regulations.
DANGER
Electric shock
Death or serious personal injury
‐ Before removing the terminal box
cover and before removing or
dismantling the pump, make sure that
the power supply has been switched
off. Connect the pump to an external
main switch with a minimum contact
gap of 3 mm in all poles.
‐ The pump must be connected to an
external main switch close to the pump
and to a motor-protective circuit
breaker. Make sure you can lock the
main switch in OFF position (isolated).
Type and requirements are specified in
EN 60204-1, 5.3.2.
DANGER
Electric shock
Death or serious personal injury
‐ The motor must be protected against
overload by an external motor-
protective circuit breaker with IEC trip
class 10 or 20.
‐ We recommend that you use trip class
20.
‐ The current setting of the motor-
protective circuit breaker must be
adjusted to the nominal current stated
on the motor nameplate.
The operating voltage and frequency are stated on
the pump nameplate. Make sure that the motor is
suitable for the power supply on which it will be used.
Single-phase standard motors incorporate a thermal
switch and require no additional motor protection.
Three-phase motors must be connected to a motor
protection device.
Motors of 3 kW and up incorporate thermistors (PTC).
The thermistors are designed according to DIN
44082.
Make the electrical connection as shown in the
diagram inside the terminal box cover.
The motors of twin-head pumps are to be connected
separately.
4.4.1 Cable entry/screwed connection, MG motor
All motors are supplied without screwed cable entries.
The table below shows the numbers and sizes of
cable entry holes of the terminal box of Grundfos MG
motors according to the standard EN 50262.
Frame
size
Model
Number x
dimensions
Description
MG 71
and 80
B, C 2 x M20 x 1.5
The holes have
precast threads
and are closed
with knock-out
cable entries.
MG 90
and 100
B, C, D 4 x M20
The holes are
closed with
knock-out cable
entries.
MG 112
and 132
C, D, F,
H
4 x M25
MG 160
and 180
F, H
4 x M40
2 x M20
4.4.2 Frequency converter operation
Motor types Siemens, MG 71 and MG 80
for supply voltages up to and including 440
V (seeing the motor nameplate) must be
protected against voltage peaks higher
than 650 V between the supply terminals.
16
English (GB)