Tecfluid TR420 - Manual (Page 4)

2.3 Output connection
In case of current output (4-20 mA), it is recommended that the impedance of the receiver
does not exceed 350 Ω.
3 TEST AND ADJUSTMENTS
3.1 Testing
Remove the transparent cover, and access to the eight contact DIP switch. Move the
switches 1 & 2 to the "OFF" position and switches 3 & 4 to the "ON" position (TEST
configuration). The LED lamp lights up, indicating TEST mode. Use the four switches 5, 6, 7
& 8 to select the different output levels. With all four switches in the "OFF" position we have
an output equivalent to 0% of level and with all four switches in the "ON" position we have an
output for a 100% of level.
No. in ON Level Output
NONE 0 % 4 mA
5 25 % 8 mA
5 & 6 50 % 12 mA
5, 6 & 7 75 % 16 mA
5, 6, 7 & 8 100 % 20 mA
In order to visualise the output current, use the level indicator provided in the plant or
alternatively use a multimeter on the scale of mA.
When the test procedure is over, move the switches 1, 2, 3 & 4 to the normal service
position and the LED lamp will turn off.
3.2 Adjustment
The converters include two potentiometers for adjusting the output range with the individual
probes installed. The potentiometer P01 (marked ZERO on the face plate) is used to adjust
the 0 point, and the potentiometer P02 (marked SPAN) is used to adjust the full scale output
(100% of the level). Adjustment must be made with the switches in "SERVICE" position.
In order to reach the adjustment potentiometers, one must use a fairly long fine screwdriver
since the screw heads of the potentiometers are situated at about 25 mm below the face
plate.
In order to adjust the output the float must be placed at the minimum level position. Then
adjust P01 for a 4 mA output (or minimum output in the event of using other output modes).
Place the float at the maximum level position and adjust P02 to obtain 20 mA or the
maximum output.
4. SELECTION OF OUTPUT MODES
The level converter is designed to have 6 possible output modes that can be adapted to
different signal receivers. All output modes are active outputs, which means that the
converter supplies the current or voltage to the receiver.
The six output modes are the following:
1. 4 - 20 mA output
2. 0 - 20 mA output
3. 1 - 5 V output
4. 0 - 5 V output
5. 2 - 10 V output
6. 0 - 10 V output
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