Tabla de contenido
Idiomas disponibles
Idiomas disponibles
SY -N
GAS CONCENTRATION TRANSMITTERS FOR NON-CLASSIFIED ATEX
ZONES.
12..24Vdc Power supply
4..20mA Output and Modbus®
Predisposition for relay board installation + LED (optional)
──────────────────────────────────
OVERVIEW
──────────────────────────────────
The gas concentration transmitters of SY-N
Series are made by the following components:
Gas sensor.
Electronic circuit for conversion.
Terminals for power supply and electrical
connection of output signals.
Case (plastic or alluminium) and its sensor-
holder with protection filter.
On the following diagrams, the shown case is
the plastic one but the same diagrams are also
valid for the die-cast alluminium case. The
device can carry sensors for different gases,
both combustible and toxic.
The mounted terminals provide by standard
both an analog current output (4..20mA) and a
digital Modbus® output.
──────────────────────────────────
TRANSMITTER IDENTIFICATION
──────────────────────────────────
The transmitter code indicates what gas it
detects and with what full-scale. The features of
the device are, anyhow, explicitly described on
the product label. Sensors for other gases are
made on specific request to the manufacturer.
──────────────────────────────────
OPERATION
──────────────────────────────────
The transmitter code indicates which gas it
detects and with which full-scale. The features
of the device are, anyhow, explicitly described
on the label stuck on the product. Sensors for
other gases are made on specific request to the
manufacturer.
──────────────────────────────────
OUTPUT SIGNAL (4..20mA Output)
──────────────────────────────────
General example of Concentration-Current
output relation for a Combustible gas
transmitter with 4..20mA output and full-
scale defined as FS.
Fig. 1.
Gas Concentration
Table of correspondence between generic
concentration in fractions of full scale (F.S.)
and output current (mA)
Concentration
Fault current loop
Sensor end-life
Sensor fault
0
1/4 Full-scale
1/2 Full-scale
3/4 Full-scale
Full-scale
Over Range ( >500ppm)
Tab. 1.
SY-N000000SE 034969 310720
USE AND MAINTENANCE MANUAL
Specific example of Concentration-Current
output relation for a Combustible gas
transmitter with 4..20mA output and full-
scale 50% L.E.L.
Fig. 2.
Gas Concentration (%L.E.L.)
Table of relation between gas concentration (%
L.E.L.) and output current (mA)
%
n-Butane
%L.E.L.
(CAS
106.97.8)
Detected
LPG
gas
Fault current Loop
0 %
0.00 %
10 %
0.14 %
20.0 %
0.28 %
50.0 %
0.70 %
Over Range ( >50% L.E.L.)
Tab. 2.
Specific example of Concentration-Current
output relation for a Combustible gas
transmitter with 4..20mA output and full-
scale 100% L.E.L.
Fig. 3.
Gas Concentration (%L.E.L.)
Table of relation between gas concentration (%
L.E.L.) and output current (mA)
%
n-Butane
% L.E.L.
(CAS
106.97.8)
Output (mA)
Detected
LPG
0.0
gas
1.0
2.0
4.0
8.0
0 %
0 %
10 %
0.14 %
12.0
20.0 %
0.28 %
16.0
100.0 %
1.40 %
20.0
Over Range ( >100% L.E.L.)
22.0
Tab. 3.
v
v
v
/
%
/
%
/
v
v
v
Methane
n-Octane
Output
(CAS
(CAS
(mA)
74.82.8)
111.65.9)
METHANE Fuel Vapors
0.0
Sensor end-life
1.0
2.0
Sensor fault
0.00 %
0.00 %
4.0
0.44 %
0.08 %
7.2
0,88 %
0.16 %
10.4
2.20 %
0.40 %
20.0
22.0
v
v
v
/
%
/
%
/
v
v
v
Methane
n-Octane
Output
(CAS
(CAS
(mA)
74.82.8)
111.65.9)
METHANE Fuel Vapors
Fault current loop
0.0
Sensor end-life
1.0
Sensor fault
2.0
0.00 %
0.00 %
4.0
0.44 %
0.08 %
7.2
0,88 %
0.16 %
10.4
4.40 %
0.80 %
20.0
22.0
Pag. 11/32
Via del Commercio, 9/11- 36065 Mussolente (VI)
Tel.: +39.0424.567842 - Fax.: +39.0424.567849
http://www.seitron.it - e-mail: [email protected]
Specific example of Concentration-Current
output relation for toxic gases transmitter
with 4..20mA and full-scale 500 ppm.
Fig. 4.
Gas Concentration
Table of relation between gas concentration
(ppm) and output current (mA)
ppm
Fault in current Loop
Sensor end-life
Sensor fault
0
125
250
500
Over Range ( >500ppm)
Tab. 4.
Fault status:
If the electric board or the sensor inside the
transmitter fails, the system detects the error
and sends the output current loop at 2.0 mA.
This feature makes available an error that can
be distinguished from the one due to the
interruption of the current loop, which appears
naturally to the unit as 0.0 mA.
In other words, this function allows a 'differential
diagnosis', making it easier to resolve the
problem.
Over-range status:
If the gas concentration exceeds the range limit,
the current output value is fixed at 22 mA, this
way allowing to detect an over-range condition
through the unit to which the sensor is
connected.
──────────────────────────────────
OUTPUT SIGNAL (Modbus® output)
──────────────────────────────────
The terminals output signal Modbus® is
compatible with the physical standard RS485.
──────────────────────────────────
MECHANICAL INSTALLATION
──────────────────────────────────
Install the transmitter steadily on a wall using
accessories (screws and dowels) suitable for
the installation surface.
The part containing the gas sensor must be
with the face downwards, this way protecting it
from a possible water infiltration.
About the precautions to be taken to obtain a
good functional behavior of the device, it is
important to say that, about the disposition of
the sensors inside the room that must be
controlled, a particular attention must be payed
to:
Output (mA)
0.0
1.0
2.0
4.0
8
12
20
22.0
ENGLISH
Tabla de contenido
