IST-2136.IC01.01
Istruzione / User’s Manual / Manuel d’utilisation
Pag.5/10
TECNOCONTROL S.r.l. Via Miglioli 47 SEGRATE ( MI ) ITALY
Tel. +39 02 26922890 - Fax +39 02 2133734
"zero" value. The difference signal between the two detectors provides the value of the gas concentration. The ad-
vantage of this technique is that it is selective for gases such as carbon dioxide, which is difficult to measure with
other methods, and also has the advantage of compensating, in time, the changes of detector sensitivity. The only
interference, may be given from presence of water vapour, which absorbs infrared.
Preheating
: when powered, the sensor needs a time of preliminary heating of about 60 seconds. During this peri-
od the yellow LED “
FAULT
” flashes. After this period, the yellow LED light off, the green LED “
ON
” illuminates to in-
dicate normal functioning. After this period the unit is able to detect gas even if it attains the optimum stability con-
ditions after about 10÷30 minutes continual functioning (
only after this time, can be made the calibration check
).
Normal operation
: the green LED “
ON
” should be light on.
ALARMS:
three alarm levels, can be set by Dip-Switch (
see tables 2
). There are two different alarm methods, the
normal one, will activate the corresponding relays after a fixed delay, the advanced one, operate with TLV-TWA,
STEL and C value, will activate the relays without delay.
The 1st red Led
(
ALARM 1
) illuminates when the gas concentration attains 1st alarm level. Under normal alarm
method, after about 12 seconds the “
ALARM 1
" relay will activate, while under advanced one, with TLV-TWA level
selected, the relay will activate without delay.
The 2nd red Led
(
ALARM 2
) illuminates when the gas concentration attains 2nd alarm level and after about 30
seconds, the “
ALARM 2
" relay will activate or without delay when TLV-STEL level is selected.
The 3rd red Led
(
ALARM 3
) illuminates when the gas concentration attains 3rd alarm level and after about 60
seconds, the “
ALARM 3
" relay will activate or without delay when TLV-C level is selected.
TLV (
T
hreshold
L
imit
V
alues
)
are defined as an exposure limit to which it is believed nearly all workers can be exposed
day after day for a working lifetime without ill effect.
TLV-TWA (
T
hreshold
L
imit
V
alue–
T
ime-
W
eighted
A
verage
)
is the time-weighted average concentration for a conventional
8-hour workday and a 40-hour workweek, to which it is believed that nearly all workers may be repeatedly exposed,
day after day, without adverse effect.
TLV-STEL
(
T
hreshold
L
imit
V
alue–
S
hort-
T
erm
E
xposure Limit
)
is the concentration to which it is believed that workers can
be exposed continuously for a short period of time without suffering from irritation, chronic or irreversible tissue
damage, or narcosis. STEL is defined as a 15-minute TWA exposure, which should not be exceeded at any time
during a workday.
TLV-C (
T
hreshold
L
imit
V
alue-
C
eiling
)
is the concentration that should not be exceeded during any part of the working exposure.
The values are recommending exposure levels that are protective to workers, OSHA (
O
ccupational
S
afety and
H
ealth
A
dministration
, of the U.S. Department of Labour) and COSHH
(
C
ontrol Of
S
ubstances
H
azardous to
H
ealth in Europe
).
FAULTS
:
the Yellow LED (
FAULT
) illuminates, the "
S
" output falls down to 0mA (
The different faults are listed below
) and
the “
FAULT
”
normally activated relay (NC contact), will deactivate. The "
FAULT
" relay, if necessary, can be used both
to signal remotely an occurred damage and to signal the absence of power to the instrument.
Yellow LED illuminates each 3 seconds (
with green LED activate
):
this happens when the “
Sensor
” has overcome
its period of life (about 5 years) and its correct operation is not longer guaranteed. The detector keeps on operating
normally but it is necessary, as soon as possible,
replace and / or send it back to the supplier to replace the “
Sensor
”
with a new one.
Yellow LED activate, green LED off (
FAULT relay activates and 0 mA output signal
):
this signal different kind of faults.
1)
The Dip Switch set up is wrong, please verify (
see Table 2
).
2)
The “
Sensor
” is not working, (fault sensor or no
communication or uncorrected). Performed the checks turn off then on the device. If the condition persists, please
replace the unit and/or send it back to the supplier for repair.
Yellow and green LED activates (
FAULT relay activates and 0mA output signal
):
this happens when the “
Sensor
” is not
working. First try to turn off then on the device. If the condition persists, please replace the unit and/or send it back
to the supplier for repair.
INSTALLATION
The detectors must be installed, positioned and carried out maintenance, following all the applicable national regu-
lations for electrical installations and safety standards of the plant.
Mounting
: The
Fig. 1
shows the instrument size. The unit must be positioned vertically. The unit must be positioned
vertically with the sensor downwards.
SE136 IC2
positioning
:
s
hould be fixed at 20-30 cm from the floor (CO
2
gas is heavier than air).
Electrical Connection (
see Fig.2
)
: the maximum distance to install each detector from the from the power supply is
show in
table 1
. If more than one detector is to be powered in parallel, it is necessary to consider the voltage drop
across the supply cable. Normally use a two wire cable (
not shielded
) for power the wire for output relays.
NOTE
: If is also used the mA output signal, please use 3 wire shielded cable + conductors for relay output. The
max load resistor is 50 ohm with 12Vdc power supply, while is 400 ohm with 24Vdc power supply (
see fig.4
).
Power Supply terminals, on the main board, are plug-in type, it is necessary to extract them to make the connec-
tion, pay attention when you insert them again, being polarized. The relays terminals, on outputs board, are fixed.
The sealed relays are
tension free
SPST (
S
ingle
P
ole
S
ingle
T
hrow)
contacts and should be set NO (Normally Open) or
NC (Normally Closed) by positioning the 4st Dip-Switch (
see Table 3
). With the
Dip-Switches from 1 to 3 the concen-
tration for alarm activations is determined. Alarms can be set with TLV-TWA and STEL functioning (
see Table 2
).
NOTE: Dip-Switch should be set with instrument powered off. Dip-Switch settled in reserved positions ac-
tivates FAULT Led indication (see “Operational Description > Faults”).
