Emerson Rosemount 3490 Series Reference Manual page 100

Getting started
January 2021
Figure 4-22: Pump 1 and Pump 2 are Off (Level Okay)
E
A. Level in m
B. 8.0 m (P421)
C. 5.0 m (P411)
D. 2.0 m (P412)
E. Pump 1
F. Pump 2
When the level rises above 5 m (On point, P411), the relay RL1 is energized to start Pump 1
(Figure
Figure 4-23: Pump 1 is On (Rising Level Above 5 m)
E
A. Level in m
B. 8.0 m (P421)
C. 5.0 m (P411)
D. 2.0 m (P412)
E. Pump 1
F. Pump 2
If the level continues to rise and is above 8 m (On point, P421), relay RL2 is energized to
start Pump 2 and assist Pump 1. Relay RL1 stays energized to keep Pump 1 pumping
(Figure
100
A
B
C
D
F
4-23).
A
B
C
D
F
4-24).
Reference Manual
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