VEGA VEGASEL 543, 544, 545, 546, 547 - Manual (Page 14)

14 VEGASEL
Set-up
4.3 Switch point adjustment
Single point level switch (VEGASEL 544, 545, 546)
Coded key 2
Coded key 1
on 1 off 1 on 1 off 1
on 2 off 2 on 2 off 2
Level
The above figure is also valid for VEGASEL with only 1, 3 or 4 relays.
The feature of a single point level switch is the switching to on/off at a point of the input signal. This switch point is
adjusted via a coded key on the front panel. The hysteresis can be selected via DIL-switches on the board
between low hysteresis (approx. 1 %) and high hysteresis (approx. 3 %). With a VEGASEL as single point level
switch the following functions can be obtained: overfill protection, protection against dry running of pumps or
switch on/off of a heating or a stirrer at certain level.
With the coded keys, the %-values are adjusted which relate to the ∆ of the input signal.
Example: Input4 … 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
The effect of the hysteresis depends on the adjusted mode.
Example 1: Switch point 75 %, mode A, hysteresis 1 %
Switching condition: off 75 %, on 74 %
Example 2: Switch point 25 %, mode B, hysteresis 3 %
Switching condition: off 25 %, on 28 %
Time
5 7
5 2
d6 b6 z6
100%
75%
25%
0%
d10 b10 z10
d6 b6 z6 d6 b6 z6 d6 b6 z6 d6 b6 z6
d10 b10 z10 d10 b10 z10
Mode A
Relay 1
LED 1
Mode B
Relay 2
LED 2