Electrical Connection - Grundfos CRK Series Instructions Manual

3.2.1 Inlet conditions
The bottom of the pump strainer must be at least 25
mm above the bottom of the tank.
The pumps are designed to provide full performance
down to a level of A mm above the bottom of the
strainer.
At a liquid level between A and B mm above the
bottom of the strainer, the built-in priming screw will
protect the pump against dry running.
MTR 32, 45 and 64 pumps have no priming screw.
Pump type
CRK 2, 4 and MTR 1s, 1, 3, 5
MTR 10, 15, 20
MTR 32, 45, 64
Fig. 5 CRK 2, 4 and MTR 1s, 1, 3, 5, 8
Fig. 6 MTR 10, 15, 20
A [mm] B [mm]
41 28
50 25
70 -

3.3 Electrical connection

A
B
25 mm
The electrical connection must be carried out by an
authorized electrician in accordance with local
regulations.
The electrical connection must be carried out as
shown in the wiring diagram inside the terminal box
cover.
The operating voltage and frequency are marked on
the pump nameplate. Please make sure that the
A
motor is suitable for the power supply on which it will
be used.
B
Single-phase Grundfos motors incorporate a thermal
switch and require no additional motor protection.
25 mm
Fig. 7 MTR 32, 45, 64
WARNING
Electric shock
Death or serious personal injury
- Before starting any work on the product,
make sure that the power supply has
been switched off and that it cannot be
accidentally switched on.
- Connect the pump to an external main
switch close to the pump and to a
motor-protective circuit breaker or a
CUE frequency converter. Make sure
that you can lock the main switch in
OFF position (isolated). Type and
requirements as specified in EN 60204-
1, 5.3.2.
A
25 mm
5