Instruction manual

Page 72
Example 3 Reservoir Control (pump up)
A reservoir is typically used to temporarily hold liquid, and when the level
reaches a specific low point, the reservoir is pumped up.
empty distance (P105), 11.0 feet
100%, span (P106), 10.0 feet
10% , low alarm on (P213), 1.0 feet
15% , low alarm off (P214), 1.5 feet
80%, pump 1+2 off (P224, 234), 8.0 feet
0% , empty level
50%, pump 2 on (P 233), 5.0 feet
70%, pump 1 on (P 223), 7.0 feet
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 7.0 feet, and pump up to
8.0 feet. 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
7.0 feet, pump 2 will come on at 5.0 feet and pump up to 8.0 feet. 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 1.0 feet, then the alarm
relay (relay 1) will come on, and go off when the level rises to 1.5 feet. 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 = 10.0
feet (100%)