K-O2 Oxygen Sensor
5/20/2022
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
Page 7
www.kele.com
Dip switch
Setting
OXYGEN %
Warn Alarm
19.8
19.5
20.0
19.5
20.3
20.0
20.5
20.0
Table 8
: Concentration Threshold
Settings
.
Mode
Front Cover LED
Analog Output
Relays Actuated
Comment
Normal
Steady Green,
Yellow or Red
4 – 20 mA
Depends on
concentration
During normal operation
Standby Various
20 mA
NONE
During start-up interval or any time during
calibration
EOL
warning
Slow Blinking
Yellow
4 – 20 mA
Depends on
concentration
Sensor nearing the end of its rated service
life.
Relays and analog output function normally.
Sensor
Expired Slow Blinking Red
4 mA
Warning /
Ventilation
After calibration of expired sensor.
Sensor is no longer operational.
Table 9
: K-O2 Operating Modes
4.2 W
ARNING
/V
ENTILATION AND
A
LARM
C
ONDITIONS
Two, 10 Amp, 120/277 VAC rated, dry-contact, SPDT relays activate during
warning/ventilation and alarm conditions: refer to
Section 3.2
for wiring
information.
When the concentration of
oxygen falls below its configured
warning/ventilation threshold, the
WARNING/VENTILATION
relay output is
activated. When the concentration falls below the alarm threshold, the
controller’s
ALARM
relay is also activated. When the oxygen concentration
rises above the alarm threshold, the
ALARM
relay is deactivated; when it rises
above the ventilation threshold the
WARNING
/
VENTILATION
relay is also
deactivated.
4.3 S
ETTING
V
ENTILATION AND
A
LARM
T
HRESHOLDS
The four, factory-preset pairs of ventilation and alarm levels are shown in
Table 8. Each setting determines both the controller’s warning/ventilation
and alarm thresholds.
The active threshold values are selected by setting the two DIP switches on
the main board (see Figure 8) as shown in the first column of Table 8 for the
desired setting.
4.4 C
ONCENTRATION
R
EPORTING
In normal mode, oxygen concentration readings from the sensor are
reported by the controller’s powered 4 – 20mA current loop output. The
output connector location is shown in
Figure 6
. Output scaling is as shown
in Table 5.
O
2
Federal OSHA Personal Exposure Limit (PEL) .
19.5 %
Figure 8
DIP Switch Locations