Electrical Connection; Wiring Diagrams; Motor Protection - Grundfos AMG Series Installation And Operating Instructions Manual

6. Electrical connection

Electrical connections must be carried out by a
qualified electrician in accordance with local
regulations.
WARNING
Electric shock
Death or serious personal injury
‐
Before making electrical connection,
make sure that the fuses have been re-
moved or the main switch has been
switched off. Make sure that the power
supply cannot be switched on uninten-
tionally.
The explosion protection classification of
the mixer or flowmaker is
Ex eb h ib IIC T3 Gb.
The classification of the installation must
be approved by the local authorities.
The supply voltage and frequency are marked on the
nameplate. Make sure that the mixer or flowmaker is
suitable for the power supply available at the
installation site.
The mixer or flowmaker is supplied with a 10 m cable
(standard length, suitable for up to 7 m deep tanks).
Standard cable lengths (15 and 25 metres) are
available on request.
The motor is marked either with a Y (star) or a
Δ (delta). Make this connection in an external control
panel using conductors 1 to 6 of the power supply
cable.
Figure Schematic drawing of delta and star
connection shows a schematic drawing of these star
and delta connections. If the mixer or flowmaker is
connected in delta during operation, the mixer or
flowmaker can be started in star-delta starting.
Three-phase motors
1
W2 U2 V2
W1
U1 V1
L1
L2 L3
Schematic drawing of delta and star connection
Pos. Description
1 Delta
2 Star
24
2
V2
U2
W2
W1
V1
U1
L1
L2
L3

6.1 Wiring diagrams

U1 V1 W1 W2 U2 V2
Three PTC sensors
Terminals Description
Ends of the three stator windings
1, 2, 3, 4, 5, 6
(U1, V1, W1, W2, U2, V2)
PTC sensors according to DIN
31, 32
44081 (ϑ1, ϑ2, ϑ3)
21, 22 Leakage sensor in gearbox (B)

6.2 Motor protection

The following motor protections are available.
Explosion-proof mixers and flowmakers
Explosion-proof mixers and flowmakers incorporate
three PTC sensors (temperature sensors) according
to DIN 44081. See fig. Three PTC sensors.
PTC sensors
In case of overheating, the motor stops.
Automatic restarting is not permitted.
This requires a thermistor trigger unit with a
reconnection suppressor in the control circuit of the
motor contactor.
ϑ1, ϑ2, ϑ3: PTC sensors:
• Two conductors (terminals 31 and 32).
• Maximum voltage at the terminals: U
(AC/DC).
PTC LS PE
= 2.5 V
max.