ULTRATWIN (UL)
INSTRUCTION MANUAL
58
Example 4 Differential Control
In this example the UltraTWIN is being used to control a rake on a screen,
which is filtering out solids in the inlet flow to a wastewater treatment plant.
A
high alarm
has been assigned to Point 1 (
Transducer 1
), on the
upstream
side and a
low alarm
, to Point 2 (
Transducer 2)
on the
downstream
side. The Diff. Control, to operate the rake is on relay 1, high
alarm, on Transducer 1 (upstream), is on relay 2 and, low alarm, on
Transducer 2 (downstream) is on relay 3.
Important Notice
In this example, the transducers are mounted at the same height. If the
transducers are mounted at different heights, ensure that the empty levels
are correct such that there is no differential present when the level is zero
on both sides.
0%. Empty Level
Empty Distance (P105), 11.0 feet
100%. Span (P106), 10.0 feet
85%. Pt 1, high alarm on (P223), 8.5 feet
80%. Pt 1, high alarm off (P224), 8.0 feet
10%. Pt 2, low alarm on (P233), 1.0 feet
15%. Pt 2, low alarm off (P234), 1.5 feet
1%. Differential control on (P214), 0.1 feet
5%. Differential control off (P223), 0.5 feet
{
Point 1
(Up Stream)
Point 2
(Down Stream)
