Wiring Diagrams; Cu 100 Control Box - Grundfos DP 10.50 Original Installation And Operating Instructions

8.1 Wiring diagrams

L N
PE
PE
1 2 3 4
T2
˚
160
1
Fig. 5 Wiring diagram for single-phase pumps
PE L1 L2 L3
PE
1 2 3 4
T2
170 ˚
3
Fig. 6 Wiring diagram for three-phase pumps

8.2 CU 100 control box

The CU 100 control box incorporates a motor-
protective circuit breaker and is available with level
switch and cable.
Single-phase pumps: A run capacitor must be
connected to the control box.
For capacitor size, see the table:
Pump type
DP and EF
Start and stop levels: The difference in level
between start and stop can be adjusted by changing
the free cable length.
Long free cable = large difference in level
Short free cable = small difference in level.
Both the two following points must be
Note
observed.
18
5 6
T1 T3
˚
C 150 C
5 6
T1 T3
C 150 ˚ C
Run capacitor
[μF] [V]
30 450
• To prevent air intake and vibrations, install the
stop level switch in such a way that the pump is
stopped before the liquid level is lowered below
the upper edge of the clamp on the pump.
• Install the start level switch in such a way that
the pump is started at the required level; however,
the pump must always be started before the liquid
level reaches the bottom inlet pipe to the tank.
Warning
The CU 100 control box must not be
used for Ex applications.
See section 8.3 Pump controllers.
Warning
The pump must not run dry.
An additional level switch must be
installed to ensure that the pump is
stopped in case the stop level switch is
not operating. See fig. 7.
The pump must be stopped when the
liquid level reaches the upper edge of
the clamp on the pump.
Float switches used in potentially
explosive environments must be
approved for this application.
They must be connected to the
Grundfos DC, DCD or LC, LCD 108
pump controller via an intrinsically safe
barrier to ensure a safe circuit.
Fig. 7 Start and stop levels
Alarm
Start
Stop
Additional
stop