VEGA VEGASEL 543, 544, 545, 546, 547 - Manual (Page 15)

VEGASEL 15
Set-up
Two-point level switch (VEGASEL 543, 545, 547)
Coded key
max.
Coded key
min.
Mode A
Relay 1
LED 1
off off
on on
The above figure is also valid for VEGASEL 547 with 2 relays.
The feature of a two-point level switch is the hysteresis between the switching to on/off at two different points of
the input signal. The switch points and therefore the hysteresis are adjusted via the coded keys in the front panel
between 1 % and 99 %. With VEGASEL as two-point level switch the automatic filling and emptying of a vessel
can be controlled, or overfill protection and protection against dry running of pumps can be obtained.
With the coded keys, the %-values are adjusted which relate to the ∆ of the input signal.
Example: Input 4 … 20 mA, Switch point at 75 % and at 25 %
∆ = 20 mA – 4 mA = 16 mA
75 % of 16 mA = 12 mA
25 % of 16 mA = 4 mA
Switch point 75 % corresponds to 4 mA + 12 mA = 16 mA
Switch point 25 % corresponds to 4 mA + 4 mA = 8 mA
If both coded keys are set to the same value, a single point level switch is obtained with a hysteresis of
approx. 0,5 %.
Level
Time
5 7
5 2
100%
75%
25%
0%
d12 b12 z12 d12 b12 z12 d12 b12 z12 d12 b12 z12