
EsiWelma Srl URD20SL_en.doc - rev. 0 CO
2
gas detectors – URD20SL
24/09/2010 Gas detection systems for industrial environments 4/8
Electrical Installation
Terminal board and
electrical connections
Cabling:
Configuration:
4…20mA Output
reference selection:
4...20mA signal
operating mode
configuration:
Setting threshold limit
values:
CAUTION: Make the area safe and make sure that the device power supply is
off before cabling and configuration operations.
Install the sensor in compliance with laws in force.
The cable gland provided on the housing is used for cable entry.
Ground the sensor using the internal grounding system.
Ground connection
Terminal Board TB1
+
12…24Vdc
-
-
4…20mA
+
JP2 jumper circuit
S1 DIP switch
Depending on the connecting distance, use at least 3-core cable, min diameter
0.75mm2up to 100mm2, 1mm2up to 200mm2, 1.5mm2up to 500mm2.
Use shielded cable where there is a risk of electromagnetic interference.
If a relay card is used, use multi-core cable suitable for the number of connections.
Default settings of the sensor are shown in the “Technical Specifications” chapter.
In order to change the default settings, switch off the power supply, input the new
settings at the JP2 jumper circuit or at the S1 DIP switch as shown in the diagram,
then power-up again; in particular:
The default setting for the 4-20mA signal is the negative power signal. Output
reference selection should be made by JP2 triple of jumpers; to change this setting,
operator has to move JP2 jumpers as shown in the figure:
Caution: if the default settings are changed,
the connections on the TB1 terminal board
will be inverted.
Ref. at - (default) Ref. at
To set the operating mode of the 4...20mA signal, it is necessary to use the 5th
selector of the DIP switch at S1; in particular:
Proportional Threshold mode
To set the threshold limit values of the optional relay card, or of the threshold operating
mode of the 4...20mA signal, it is necessary to use the first four selectors of the DIP
switch at S1; in particular, the thresholds, given in full scale percentage, will be:
Sensor
card
Relay card
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
CN4 connection for handheld
terminal
Connection slot
for relay card
CUSTOM
*
3
5
10% 5
10
15% 5
10
20% 10
15
25% 10
15
30%
10, 20, 40% 10, 25, 35% 15, 25, 40% 15, 30, 45% 25, 35, 50% 20, 40, 60%
(DEFAULT)
20
40
80% -----------------Future im
lementations------------------
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
(*) When the first four selectors
of the DIP switch are in OFF
position, the threshold limit
values can only be set by the
TUS40 handheld terminal.
If this is selected without using
the handheld terminal, the
detector will automatically se
the default threshold limi
values. To set the detecto
with the handheld terminal, see
the dedicated instruction
manual.