Wiring Diagrams; Start And Stop Levels - Grundfos SEG Instrucciones De Instalación Y Funcionamiento

9.1 Wiring diagrams

Wire no. Type
1 Common (C)
2 Run (R)
3 Start (S)
Wiring diagram for single-phase pumps
Fig. 4
Wiring diagram for three-phase pumps
Fig. 5
12
275 °F (135 °C) and
257 °F (125 °C)
below apply to
single-phase, 2 hp
(1.5 kW), pumps
302 °F/
320 °F/
275 °F 257 °F
(160 °C/ (150 °C/
125 °C)
135 °C
Connection
U1 / Z1
U2
Z2
338 °F 302 °F
(170 °C) (150 °C)

9.2 Start and stop levels

The difference in level between start and stop can be adjusted by
means of the installed level detecting equipment.
Note
Note
Both the two following points must be observed.
• 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 pit.
The pump must not run dry. Install an additional level
switch to ensure that the pump is stopped in case the
stop level switch is not operating. Stop the pump
when the liquid level reaches the upper edge of the
FM
clamp on the pump. Float switches used in explosive
environments must be approved for this application.
They must be connected to a controller via the
intrinsically safe LC-Ex4 barrier to ensure a safe
circuit.
Warning
Install an additional level switch to ensure that the
FM
pump is stopped in case the stop level switch is not
operating. See fig. 6.
Start and stop levels
Fig. 6
Alarm
Start
Stop