Sentera Controls RTVS8 Series, Mounting And Operating Instructions

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MIW-RTVS8-EN-000 - 16 / 02 / 2022 11 - 13
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RTVS8
115—230 VAC TRANSFORMER FAN SPEED
CONTROLLER WITH MODBUS RTU COMMUNICATION
3.2.1 Automatic forward mode. See operational diagram below:
Each level can take a value from 0 to 100 % with the following restrictions:
0 = OFF, i.e. the step is skipped. For example: Step 1 = 17 %, Step 2 = 34
%, Step 3 = 0 %, Step 4 = 68 %, Step 5 = 85 %, from 34 to 68 % the device
will be in Step 2 and above 68% - in Step 4. Each step threshold restricts
by the steps above and below with minimum of 11% difference, so when
the hysteresis is set at 10% the thresholds will not overlap. For example:
Step 1 = 17 %, Step 2 = 34 %, Step 3 = 51 %, Step 2 can take values from
28 % to 40 %. The Hysteresis delta is asymmetric, valid when the input
value is transitioning from high to low values. The device will subtract the
value of Δ from the step threshold and the step will change below the
resulting value. For example: Step 3 = 51 % threshold, Hysteresis delta =
2 %, Step 3 will be ON above 51% and OFF below 49 %. An example of
forward switching mode when Min Step = 0 and Max Step = 5 is given in
Fig. 4 below. The thresholds are at 17 % and hysteresis delta is set from
2 to 10 % via Holding Register 16 (see Fig. 4 ).
Fig. 4 Automatic mode ‘forward’: Low to high speed
68 85
110
0
140
170
190
230
17 34 51
Δ
25 50 75 100 1
0
Δ
140
170
190
230
Modbus RTU
control signal
[%]
Hysteresis
2—10 %
Uout (VAC)
3.2.2 Automatic reverse mode. See operational digram below:
The higher the Input value, the lower the output. See the operational
diagram below for an example with steps from 2 to 5
. An example of
Auto Reverse mode, the steps threshold configuration is as follows:
Step 1—0 %, Step 2—75 %, Step 3—50 %, Step 4—25 %, Step 5—1
% (can be as low as 0,1 %) is given in
Fig. 5 below. When the Input
value is above 1%, device switches to Step 5, above 25 % Step 4, above
50 % Step 3, above 75 % Step 2 up to 100 %. When the Input value
decreases, the hysteresis delta is subtracted from the threshold level
and the device changes the step (see
Fig. 5 ).
Fig. 5 Automatic mode ‘reverse’: High to low speed
68 85
110
0
140
170
190
230
17 34 51
Δ
25 50 75 100 1
0
Δ
140
170
190
230
Modbus RTU control
signal [%]
Uout (VAC)
Hysteresis
2—10 %