Gearbox Protection; Overload Relays; Starting Method; Direction Of Rotation - Grundfos AMG Series Installation And Operating Instructions Manual

• Resistance between the terminals 31 and 32:
- at room temperature R = 150 to 750 Ω.
- at cutting-out temperature (130 °C) R ≥ 4000
Ω.
When the connection at terminals 31 and
32 is tested, the test voltage must not ex-
ceed 2.5 V (AC/DC). Use an ohmmeter for
the test.
Explosion-proof mixers must be protected
against overtemperature by PTC sensors.
The sensors must be connected to a certi-
fied signal converter.

6.3 Gearbox protection

The gearbox is monitored for leakage by an
incorporated leakage sensor.
The leakage sensor must be connected to a Grundfos
ALR-20/A-Ex relay
The ALR-20/A-Ex relay must be ordered separately.
Part number: 99794613 or 96489569.
If the gearbox is not monitored for leakage, inspect it
every 6 months. If the oil contains water, replace the
shaft seal.
Explosion-proof mixers and flowmakers
must be connected to the Grundfos
ALR-20/A-Ex relay. Classification: II (2)G
[Ex ib Gb] IIC.
Part number: 99794613 or 96489569.
For details on ALR-20/A-Ex, see the ALR 20/A Ex
relay Installation and operating instructions.
http://net.grundfos.com/qr/i/
99421246

6.4 Overload relays

Carry out the electrical connection to com-
ply with local regulations.
The mixer or flowmaker must be connected to a
motor-protective circuit breaker.
Connect the mixer or flowmaker to a con-
trol box with a motor protection relay with
an IEC trip class 10 or 15.
Connect the mixer or flowmaker installed
in hazardous locations to a control box
with a motor protection relay with an IEC
trip class 10.
The motor is effectively earthed by the earth
conductor of the power cables and the pipes. The
motor top cover for Ex mixers or flowmakers is
equipped with connections for external earthing or an
equipotential bonding conductor.

6.5 Starting method

6.5.1 Mixers
Continuous operation
Use direct starting for motors up to 2.2 kW.
Use star-delta starting, soft starter or frequency
converter for 3.0 kW and larger motors.
Intermittent operation
Use star-delta starting, soft starter or frequency
converter.
6.5.2 Flowmakers
Use star-delta starting, soft starter or frequency
converter.

6.6 Direction of rotation

Check the direction of rotation. When viewed from the
motor the propeller of the mixer or the flowmaker
rotates clockwise.
An arrow on the motor housing indicates the correct
direction of rotation.
If the propeller rotates in the wrong direction,
interchange two phases of the main supply (L1, L2,
L3).
25