ULTRA 3 INSTRUCTION MANUAL
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Example 3 Reservoir Control (pump down)
A sump is typically used to temporarily hold water or effluent, and when the
level reaches a specific point, the sump is pumped down, with the fluid
being transferred to another process.
In this example, there are two pumps, which will be set to alternate duty
assist, so they come on alternately. Pump 1 is to be set to relay 2, pump 2 to
relay 3, and the low-level alarm to relay 1. This will operate as follows:
During normal operation, pump 1 will come on at 1.96m and pump up to
2.24m. The setpoints are then shifted to pump 2, which will come on first
next time. During peak periods, when pump 1 cannot cope, pump 1 will
come on at 1.96m and pump 2 will come on at 1.4m and pump up to 2.24m.
The setpoints are then shifted to pump 2, which will come on first next
time. If both pumps cannot cope, and the level falls to 0.28m, then the
alarm relay (relay 3) will come on and go off when the level rises to 0.42m.
This will indicate insufficient capacity of the pumps.
The display will show the level in the sump and the mA output will be
representative of level where 4mA = empty level (0%) and 20mA = 2.8m
(100%).
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