Sitron SLU, Руководство по установке, Страница: 8 / 24

8
display unit connector
Terminal block
metal clip
+
A B
IS
ON
GND
120
display unit connector
Terminal block
metal clip
120Ω switch
Electrical Connections
The level meter is connected to the power supply or PLC or other control (evaluating) devices with a suitable cable with
the outer diameter of 6 to 8mm using screw terminals located under the display module. The recommended cross
section of cores for the current version 2 x 0.5 / 0.75 mm² and for the version with Modbus communication 2 x 2 x
0.25mm² (twisted pair, shielded). Plus pole (+U) is connected to the terminal (+), minus pole (0 V) to the terminal (-) and
the shielding (only for shielded cables ) to the terminal ( ). Communication wires A and B of the line RS-485 ( for version
M - Modbus) are connected to the terminal A and B.
Inside view of screw terminals of the level meter with current
output SLU(02/06/10/20)-C
Wiring diagram of the level meter
with Modbus SLU(02/06/10/20)-M
Wiring diagram of the level meter with
current output SLU(02/06/10/20)-C
Electrical connection must be done in de-energized state!
The supply voltage source should preferably be realized as a stabilized power supply unit with safe voltage from 18 to 36 V
DC (18 to 30 V DC for X version), which can be a part of the evaluation or display device.
With case of strong electromagnetic interferences (EMI), parallel cable ducting with power lines, or when cable length
exceeds 30 m we recommended the use of shielded cables.
Inside view of screw terminals of the level meter with Modbus
SLU(02/06/10/20)-M
Procedure to connect the cable to the level meter:
1 - Unscrew the housing cover/ lid.
2 - Using your finger tips or finger nails, gently remove display by
clutching the upper edge of the display module.
3 - If you cannot grasp the module, you can use a small screwdriver.
Insert it as far as the seam allows so that it can be nudged upward as
you work your way around the display from several sides. This will
allow you to slightly lift the module.
4 - Release the cable outlet and thread the stripped supply cable in.
5 - Connect the cable to the screw terminals according to the diagram
in Fig.17 or 18. Firmly tighten the terminals and the cable outlet.
6 - If the level meter with Modbus is involved as a terminal for RS-485,
we recommend (to avoid reflections on the line) that the 120 ohms
switch is activated. This is done by moving the small lever of the switch
marked 120 ohms to the ON position. For level meters connected to
the line RS-485 as an intermediate device (i.e. Slave), the termination
resistors are not connected (switch remains off).
7- Insert the display module back into the head so that the connectors
is properly connected. Be carefull that the position is correct or the
terminal pins may be damaged.
8- Close the housing cover and then apply a PTFE or silicone tape seal
to the threaded connection of the level meter body.
Now the level meter can be installed into the tank and wired back to the
control unit or power supply. See safety not below.
Installation Manual
Fig. 17 :
Fig. 18 :