Tecfluid TR420 - Manual (Page 3)

3
1 INTRODUCTION
The TR420 converters provide a voltage or current output proportional to the variation of
the resistance at the input.
It can be adapted to LE and LTE series of level meters, and to PT, PS and 6000 series of
flowmeters.
NOTE : Throughout the manual, indicating the word “level” means “height of the float”, and
therefore can be applied to both level meters and flow meters.
When the float position changes, the associate sensor changes its resistance, and its
value is converted to an output signal.
In all the output modes the converter is active, that is, it supplies the power, therefore the
receivers should be passive.
2 INSTALLATION
The TR420 is housed in an IP40 plastic case for mounting on a panel inside an electric
control panel. The DIP switch in the front of the converter is exclusively for testing and it
must be handled only by maintenance personnel. The plastic case has two holes for
mounting with screws to DIN 46 121 and DIN 43 660, and also it has a snap fastener for
fitting to DIN 46 277 and DIN EN 50 022 assembly rails.
Screw terminals are provided for external wiring. The terminals are protected against
accidental contact in accordance with VDE 0100 Part 750, VDE 0160 Part 100 and VBG 4.
2.1 Power supply connection
Connect the power supply voltage indicated on the label to the terminals 1 & 2.
IMPORTANT NOTE: In order to comply with the electrical safety requirements as per IEC
1010-1, the installation of the equipment must provide a mains switch to disconnect the
equipment. This switch must be marked as the disconnecting device for the equipment and
be within easy reach of the operator.
The power supply to the converter can be either 24, 110 or 220 VAC or 24 VDC. In the
event that the converter is powered at 24 V and the polarity is not indicated on the
connection label, the equipment can be connected to both 24 VAC or 24 VDC without
taking into account the polarity.
2.2 Sensor connection
The connection between the sensor and the converter TR420 needs only two wires as
indicated in the following figure.