K-O2 Wiring and Calibration Instructions
Dry contact output
Present on relay 277 V AC,10A
4-20 mA output
Present on analog
20 mA=>25%
<4 mA => sensor failed
Warning
Alarm
Power 24 V AC/DC
Electrical installation
Always install in accordance with local and national electrical
•
codes. If in doubt about the code requirements of your ap-
plication, consult a licensed electrician.
Both K-O2 enclosure styles have standard ½” conduit knock-
•
outs on all sides for power and signal wiring.
Do not use the
vent openings for wiring.
Power connection
The K-O2 Series of sensors can be powered from 20 to 30 Volts
•
AC or DC. The operating power is connected to the two-posi-
tion screw terminal connector marked “24 VAC/DC”
K-O2 with hinged cover
K-O2 with screw cover
K - O 2 C a l i b r a t i o n
A l a r m S e t t i n g s
150.8
5.94
163.5
6.44
Conduit Knockout (4 PLS)
Air Vent (2 PLS)
76.2
3.00
20.3
0.80
20.3
0.80
76.2
3.00
7.9
0.312 (4 PLS)
63.5
2.50
76.2
3.00
63.5
2.50
41.9
1.65
41.9
1.65
41.9
1.65
52
2.05
73.7
2.90
20.3
0.80
22.2
0.875 (4 PLS)
160
6.30
147.3
5.80
Air Vent (2 PLS)
Conduit Knockout (4 PLS)
52
2.05
73.7
2.90
25.4
1.00
22.2
0.875 (4 PLS)
92.7
3.65
25.4
1.00
76.2
3.00
76.2
3.00
41.9
1.65
35.6
1.40
7.1
0.281 (4 PLS)
76.2
3.00
35.6
1.40
67.310
2.65
25.400
1.00
WARNING /VENTILATION AND ALARM CONDITIONS
Two, 10 Amp, 120/277 VAC rated, dry-contact, SPDT relays activate during
warning/ventilation and alarm conditions: refer to (Section 3.2 of the Kele
K-O2 manual) for wiring information.
When the concentration of oxygen falls below its confi gured 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 deacti-
vated.
SETTING VENTILATION AND ALARM THRESHOLDS
The four, factory-preset pairs of ventilation and alarm levels are shown in
Table 6. 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 as shown in the fi rst column of Table 6.
SENSOR CALIBRATION
The sensor requires calibration at
the specifi ed calibration interval to
ensure its accuracy is maintained
over its life. Calibration is a two-step
process that provides the sensor
module with oxygen-free (or zero)
gas, and then a specifi c concentra-
tion (or span) gas. Two calibration
buttons (ZERO and SPAN) are pro-
vided on the main board as shown in
Figure 9.
FIGURE 9: Location of SPAN & ZERO Controls
Dip switch
Setting
OXYGEN %
Warn
Alarm
20.5
20.0
20.3
20.0
20.0
19.5
19.8
19.5
Table 6
POWER
ANAL
OG OUTPUT
O2
+ | -
