Kele K-O2 User manual

Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
Revision: 1/29/2021
Oxygen
Ventilation and Alarm
Controller
User’s Manual

OS-2 Oxygen Sensor
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133 Page: ii
TABLE OF CONTENTS
1 Specifications ......................................................................................................................................................... 1
2 Mechanical Installation .......................................................................................................................................... 2
2.1 Enclosure Dimensions .......................................................................................................................................... 2
3 Electrical Installation ............................................................................................................................................. 3
3.1 Analog Output Connections ......................................................................................................................... 3
3.2 Relay Connections ........................................................................................................................................ 3
3.3 Power Connection ........................................................................................................................................ 4
4 Operational Description ........................................................................................................................................ 5
4.1 Special Modes .............................................................................................................................................. 5
4.2 Warning /Ventilation and Alarm Conditions ................................................................................................ 6
4.3 Setting Ventilation and Alarm Thresholds ................................................................................................... 6
4.4 Concentration Reporting .............................................................................................................................. 7
5 Sensor Calibration .................................................................................................................................................. 7
5.1 Calibration Gases ......................................................................................................................................... 7
5.2 Zero Calibration Procedure .......................................................................................................................... 8
5.3 Span Calibration Procedure ......................................................................................................................... 9
6 Sensor Module Replacement............................................................................................................................... 10
6.1 Field Replacement of Sensor Modules ....................................................................................................... 10
7 Warranty .............................................................................................................................................................. 11
7.1 Duration ..................................................................................................................................................... 11
7.2 Limited warranty and remedies. ................................................................................................................ 11
8 Disclaimers ........................................................................................................................................................... 12
8.1 Inspection and Maintenance .................................................................................................................... 12
8.2 Life Safety ................................................................................................................................................. 12

OS-2 Oxygen Sensor
1/27/2021 Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133 Page 1 of 14
1 SPECIFICATIONS
Mechanical
Chassis Construction Industrial strength, 18 Ga. Gray powder-coated steel. Pad-
lockable, hinged or screw-on cover style available.
Weight 2.0 Lbs
Operating Temperature -20 to 50°C
Operating Humidity 15 – 90 %RH
Storage Temperature -20 to 20°C (to minimize sensor degradation)
Case Dimensions (H x W x D) 6.4” x 5.9” x 2.4” (163.5 x 150.8 x 60.7 mm)
Sensor Vents Natural ventilation through 18, 0.1” (2.54 mm) diameter vents
External Indicators Tri-color LED indicates operational status of sensor.
Knockouts 4 trade ½” knockouts (1 per side)
TABLE 1: MECHANICAL SPECIFICATIONS
Electrical
Operating Power Voltage 14 – 30 VAC (RMS) or DC
Isolated power supply; separate transformer not required.
Power Consumption < 5W
Control Relays
2 Separate SPDT line-voltage-capable relays for
warning/ventilation and alarm outputs.
10 Amps max at 120/277 VAC (RMS) or 30 VDC.
Concentration Reporting Output
Isolated, powered 4 – 20 mA current loop output.
4 mA output => 0 % concentration. 20 mA => 25%
Maximum loop resistance: 510Ω
Termination Pluggable screw-terminals for use with 12 AWG or thinner wire
TABLE 2: ELECTRICAL SPECIFICATIONS
Oxygen Sensor (O2)
Sensor Type Galvanic cell
Measurement Range 0 – 25%
Analog Output Range 4mA to 20mA (corresponds to 0 to 25%)
Accuracy ±0.2% (Typical)
Calibration Interval 6 Months
Sensor Life 2 Year (Typical)
1
Calibrated Field-Replaceable Sensor KMOD-O2
Calibration Kit UCK-3 kit
TABLE 3: OXYGEN SENSOR SPECIFICATIONS
1 Exposure to harsh ambient environmental conditions may shorten sensor life.

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Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
2 MECHANICAL I
NSTALLATION
The Model K-O2
is available in two versions of
enclosure. The removable, pad-
lockable, hinged
version is shown in Figure 2
. All electronics are attached to the front cover. There are
on all sides for electrical connections. In potential
should be used to minimize the possibility of water entry.
1.
This unit is designed to mount to a rigid, vibration
monitored about 5 feet above the floor.
2.
It should be located where there is free airflow
3.
The air vents on the sides of the enclosure should not be closer than 1 foot from the nearest
perpendicular wall and must not be ob
4.
May be mounted in any orientation but hinge on the left side is most common.
5.
Mounting holes are made for direct wall screws for the surface
provided) or switch box spacing.
2.1 ENCLOSURE D
IMENSIONS
Case Style
Mtg hole diameter
Hinged
5/16” (7.94 mm)
Screw-down
9/32” (7.14 mm)
Table 4: Mounting Hole Diameters &
Locations
FIGURE 1: HINGED FRONT PANEL E
NCLOSURE DIMENSIONS
O
S-2 Oxygen Sensor
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
NSTALLATION
is available in two versions of
an industrial-strength, 18 Gauge, gray, powder-
coated steel
lockable, hinged
-cover version is shown in Figure 1
and the screw
. All electronics are attached to the front cover. There are
trade
½” conduit knock
on all sides for electrical connections. In potential
ly damp locations the knock-
out on the bottom of the case
should be used to minimize the possibility of water entry.
DO NOT USE THE VENT HOLES FOR WIRE ENTRY.
This unit is designed to mount to a rigid, vibration
-
free surface near the middle of the area to
monitored about 5 feet above the floor.
It should be located where there is free airflow
- avoid corners or recesses.
The air vents on the sides of the enclosure should not be closer than 1 foot from the nearest
perpendicular wall and must not be ob
structed or painted-over.
May be mounted in any orientation but hinge on the left side is most common.
Mounting holes are made for direct wall screws for the surface
encountered. (Mounting screws not
provided) or switch box spacing.
IMENSIONS
Distance from center
Mtg hole diameter
Horizontal Vertical
5/16” (7.94 mm)
1.25” (31.75 mm)
1.50” (38.10 mm)
9/32” (7.14 mm)
1.50” (38.10 mm)
1.50” (38.10 mm)
Locations
NCLOSURE DIMENSIONS
Figure 2: Screw-Down
Front Panel Enclosure
Dimensions
Page 2 of 14
coated steel
and the screw
-down cover
½” conduit knock
-outs
out on the bottom of the case
DO NOT USE THE VENT HOLES FOR WIRE ENTRY.
free surface near the middle of the area to
be
The air vents on the sides of the enclosure should not be closer than 1 foot from the nearest
encountered. (Mounting screws not
1.50” (38.10 mm)
1.50” (38.10 mm)
Front Panel Enclosure

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1/27/2021
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
3 ELECTRICAL I
NSTALLATION
The controller is not equipped with a power switch; it is operational whenever sufficient power is applied to the
power input terminals.
All electrical connections to the controller are made through screw terminals that can be unplugged
landing of wires. The controll
er’s enclosure contains
installation; refer to Figure 1 and
Figure
3.1 ANALOG OUTPUT C
ONNECTIONS
The sensor’s readings are reported at the controller’s
20mA analog output connections.
Current flows out of the ‘+’
terminal and returns to the ‘-
‘ terminal
The oxygen sensor
output is provided at the terminal
Figure 3
. Analog output connection has polarity as labeled on the
controller silkscreen: care must be taken to ensure proper
connection. To wire the analog output connections:
1.
Power down the controller, this can be done by unplugging
the control
ler power terminal (see
2.
Unplug the analog output screw terminal
3. Attach the signal wires,
paying close attention to the
polarity.
4.
Plug the analog output screw terminal back into the
controller.
3.2 RELAY C
ONNECTIONS
The controller has two, 10 Amp, 120
/277
relay output connections (shown In
Figure
loads up to 10 Amps.
The relay connections have three
connectors that allow devices to be wired to the controller in
normally-open (NO) or normally-
closed (
outputs are activated when ambient air
below
the controller threshold settings (refer to
information).
In the NO Configuration
, the voltage attached to the
be present at the COM terminal
only when
activated.
In the NC Configuration
, the voltage attached to the
the relay output is deactivated:
the voltage attached to the NC terminal is removed when the relay output is
activated.
O
S-2 Oxygen Sensor
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
NSTALLATION
The controller is not equipped with a power switch; it is operational whenever sufficient power is applied to the
All electrical connections to the controller are made through screw terminals that can be unplugged
er’s enclosure contains
conduit knockouts on all sides for flexibility during
Figure
2 for details and dimensions of the enclosures.
ONNECTIONS
The sensor’s readings are reported at the controller’s
powered 4-
Current flows out of the ‘+’
‘ terminal
.
output is provided at the terminal
highlighted in
. Analog output connection has polarity as labeled on the
controller silkscreen: care must be taken to ensure proper
connection. To wire the analog output connections:
Power down the controller, this can be done by unplugging
ler power terminal (see
Figure 6).
Unplug the analog output screw terminal
labeled O1.
paying close attention to the
Plug the analog output screw terminal back into the
ONNECTIONS
/277
VAC rated, SPDT dry-contact
Figure
4) that can directly control
The relay connections have three
-terminal screw
connectors that allow devices to be wired to the controller in
either
closed (
NC) configuration. These
outputs are activated when ambient air
oxygen concentrations fall
the controller threshold settings (refer to
Section 4.2 for more
, the voltage attached to the
NO terminal will
only when
the relay output is
, the voltage attached to the
NC terminal will be present at the COM
terminal
the voltage attached to the NC terminal is removed when the relay output is
FIGURE 3: Analog Output
Figure 4:
Relay Outputs
Page 3 of 14
The controller is not equipped with a power switch; it is operational whenever sufficient power is applied to the
All electrical connections to the controller are made through screw terminals that can be unplugged
for easy
conduit knockouts on all sides for flexibility during
terminal
only while
the voltage attached to the NC terminal is removed when the relay output is
Relay Outputs

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Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
Example wiring diagram
s for relay connection
Figure 5. To wire the Warning/
ventilation
outputs:
1.
Determine if the device being attached to the relay
output should be wired in NO or NC configuration.
2.
Unplug the relay output screw terminal.
3. Connect a supply
voltage for the device being attached
to the controller’s relay output to either the
location of the screw terminal (
4.
Wire the power input of the device being attached to
the controller’s relay output to the
screw terminal.
5.
Plug the relay output screw terminal back into the
correct location on controller board.
3.3 POWER C
ONNECTION
The K-
O2 has a fully isolated, unpolarized
AC or DC operating power can
be connected in either polarity.
transformer (up to its load limit) even when they are not connect
hot/common polarity.
Power connection to the controller is made at the two
screw connector located at the bottom
(highlighted in Figure 6
). Power to the controller can be either
AC or DC voltage; DC voltage can be connected in either polarity
(see Section 1.0
for more details). To wire power:
1.
Open the controller’s enclosure and unplug the screw
terminal labeled POWER o
n the controller board.
2.
Attach power wires to the screw terminal ensuring the
connection is snug.
3.
Plug the screw terminal back into the
receptacle
on the controller board: this will cause the
controller to power up and begin operation.
It is recommended that all wired connections are made prior to
providing power to the controller.
O
S-2 Oxygen Sensor
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
Figure 6:
Location of Power Terminal
s for relay connection
are provided in
ventilation
and Alarm relay
Determine if the device being attached to the relay
output should be wired in NO or NC configuration.
Unplug the relay output screw terminal.
voltage for the device being attached
to the controller’s relay output to either the
NO or NC
location of the screw terminal (
see Figure 4).
Wire the power input of the device being attached to
the controller’s relay output to the
COM location of
Plug the relay output screw terminal back into the
correct location on controller board.
ONNECTION
O2 has a fully isolated, unpolarized
power input; either
be connected in either polarity.
Multiple K-
O2 units can operate on the same
transformer (up to its load limit) even when they are not connect
ed with the same positive/negative or
Power connection to the controller is made at the two
-terminal
screw connector located at the bottom
-right side of the board
). Power to the controller can be either
AC or DC voltage; DC voltage can be connected in either polarity
for more details). To wire power:
Open the controller’s enclosure and unplug the screw
n the controller board.
Attach power wires to the screw terminal ensuring the
Plug the screw terminal back into the
POWER
on the controller board: this will cause the
controller to power up and begin operation.
It is recommended that all wired connections are made prior to
FIGURE 5:
Example Wiring Diagram for Normally Open
Operation
Page 4 of 14
Location of Power Terminal
O2 units can operate on the same
ed with the same positive/negative or
Example Wiring Diagram for Normally Open

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Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
4 OPERATIONAL D
ESCRIPTION
The K-O2
is a ventilation and alarm con
and operates a Warning/Ventilation
contact closure that can be used to
levels of oxygen are detected. If the
oxygen
contacts is operated to trigger an alarm.
The gas sensor is
a calibrated module that
while leaving the main control mounted and wired
The front cover has an LED status
indicator
Warning/Ventilation (yellow), and A
larm
operational. While the LED is blinking red, t
The concentration of oxygen
in the ambient air is
percent by volume. The
analog output range
4.1 SPECIAL MODES
The K-
O2 operates in several modes as shown in
Normal operation is as described above. During standby
mode the sensor is stabilizing and a
nalog output is held at
20 mA.
During span calibration the senso
r’s sensitivity is
compared to its sensitivity at initial factory calibration.
its sensitivity has fallen below manufacturer’s specification
the K-O2 goes into Sensor Expired
mode with the analog
output held at 4 mA and only
the Warning/
FIGURE
7
:
FRONT COVER STATUS L
ED
O
S-2 Oxygen Sensor
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
Status LED Color
Operational Status
Description
C
oncentration
the warning/ventilation
threshold.
outputs are active.
Concentration is below
the warning/ventilation
threshold and above the
alarm threshold.
Warning/ventilation relay
is active.
Concentration is below
the alarm threshold.
warning/ventilation and
alarm relays are active
End of Life warning.
Sensor has reached the
end of its rated service life
and should be replaced.
Relays and analog
outputs continue to
function normally.
Sensor Failure.
Warning/ventilation relay
is active and analog
output is 4 mA.
(refer to
Section
Table 5: Front panel sta
tus LED Indications
during normal operation..
ESCRIPTION
is a ventilation and alarm con
troller that senses the oxygen concentration in
the ambient space around it
contact closure that can be used to
operate ventilation
fans when
oxygen
concentration approaches un
safe levels, a second set of alarm
contacts is operated to trigger an alarm.
a calibrated module that
can be replaced with minimal effort when it reaches
while leaving the main control mounted and wired
(refer to Section 7.1).
indicator
that illuminates in different colors to indicate
normal
larm
(red) conditions.
Blinking red indicates that the sensor is NOT
operational. While the LED is blinking red, t
he analog output is delivering 4
mA to indicate the error.
in the ambient air is
reported at the controller’s analog current-
loop
analog output range
s from 5 to 20mA (refer to Table 2 and Table 3).
O2 operates in several modes as shown in
Table 7.
Normal operation is as described above. During standby
nalog output is held at
r’s sensitivity is
compared to its sensitivity at initial factory calibration.
If
its sensitivity has fallen below manufacturer’s specification
mode with the analog
the Warning/
Ventilation relay activated.
ED
Page 5 of 14
Operational Status
Description
oncentration
is above
the warning/ventilation
No relay
outputs are active.
Concentration is below
the warning/ventilation
threshold and above the
alarm threshold.
Warning/ventilation relay
Concentration is below
the alarm threshold.
Both
warning/ventilation and
alarm relays are active
.
End of Life warning.
Sensor has reached the
end of its rated service life
and should be replaced.
Relays and analog
outputs continue to
function normally.
Sensor Failure.
Warning/ventilation relay
is active and analog
output is 4 mA.
Section
7)
tus LED Indications
during normal operation..
the ambient space around it
fans when
reduced
safe levels, a second set of alarm
end-of-life (EOL),
normal
(green),
Blinking red indicates that the sensor is NOT
mA to indicate the error.
loop
output as

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1/27/2021
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
Mode Front Cover LED
Analog Output
Normal Steady Green,
Yellow or Red 4 –
20
Standby Various
20 mA
EOL
warning
Slow Blinking
Yellow 4 –
20
Sensor
Expired
Slow Blinking
Red
4 mA
TABLE 7: K-O2 OPERATING MODES
4.2 WARNING /V
ENTILATION AND
Two, 10 Amp, 120/277 VAC rated, dry
-
warning/ventilation
and alarm conditions: refer to
information.
When the concentration of
oxygen falls below its configured
warning/ventilation threshold, the
WARNING/VENTILATION
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
rises above the ventilation threshold
the
also deactivated.
4.3 SETTING V
ENTILATION
The four, factory-preset
pairs of ventilation and alarm levels
Table 6
. Each setting determines both the controller’s
and alarm thresholds.
The active threshold values are
selected
the main board (highlighted in Figure
8
Table 6 for the desired setting.
Federal OSHA Pers
onal Exposure Limit (PEL)
O
S-2 Oxygen Sensor
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
Figure 8:
DIP Switch Locations
Dip
switch
Setting
Table 6
: Concentration
Settings.
Analog Output
Relays Actuated Comment
20
mA Depends on
concentration
During normal operation
20 mA
NONE During start-
up interval or any
time during calibration
20
mA Depends on
concentration
Sensor
nearing the end of
service life.
Relays and analog output function
normally.
4 mA
Warning/Ventila
tion
After
calibration of expired
Sensor is no longer operational.
ENTILATION AND
ALARM CONDITIONS
-
contact, SPDT relays activate during
and alarm conditions: refer to
Section 3.2 for wiring
oxygen falls below its configured
WARNING/VENTILATION
relay output is
activated. When the concentration falls below the alarm threshold, the
is also activated. When the oxygen concentration
ALARM
relay is deactivated; when it
the
WARNING/VENTILATION relay is
ENTILATION
AND ALARM THRESHOLDS
pairs of ventilation and alarm levels
are shown in
. Each setting determines both the controller’s
warning/ventilation
selected
by setting the two DIP switches on
8
) as shown in the first column of
O2
onal Exposure Limit (PEL)
. ≥ 19.5 %
Page 6 of 14
DIP Switch Locations
.
switch
OXYGEN %
Warn Alarm
20.5 20.0
20.3 20.0
20.0 19.5
19.8 19.5
: Concentration
Threshold
Settings.
During normal operation
up interval or any
time during calibration
nearing the end of
its rated
Relays and analog output function
calibration of expired
sensor.
Sensor is no longer operational.

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Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
4.4 CONCENTRATION R
EPORTING
In normal mode, o
xygen concentration r
20mA current loop output.
The output connector location is shown in
Table 3.
5 SENSOR C
ALIBRATION
The sensor requires
calibration at the specified calibration interval listed in
Table 3 to ensure its accuracy
is maintained over
two-step process that provides
the sensor module with
zero) gas
, and then a specific concentration (or spa
buttons (ZERO and SPAN
) are provided on the main
Figure 9.
Blinking Yellow
During gas sampling period that starts immediately
when calibration is initiated.
Blinking Green
Temporary calibration applied.
confirm or reject
Blinking Red
Failed calibration attempt.
acknowledge with either a re
Green/Yellow During
ambient equilibration
calibration.
New calibration is applied.
Red/Yellow
During ambient equilibration period after failed
calibration.
Old calibration is unchanged
TABLE 8:
Meaning of status LED blink patterns
5.1 CALIBRATION GASES
Pure nitrogen zero gas and a precise
mixture of oxygen and
oxygen sensor.
An orificed calibration adapter is
recommended to ensure tha
calibration gas
without applying higher than ambient pressure to it
A complete calibration kit that includes all the
your distributor.
Type
Mixture (by volume)
Zero gas Pure nitrogen
Span gas
20.9% oxygen
balance nitrogen
TABLE 9: Required Calibration Gases
O
S-2 Oxygen Sensor
Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133
FIGURE 9
: Location of SPAN & ZERO Controls
EPORTING
xygen concentration r
eadings from the sensor are reported by
the controller
The output connector location is shown in
Figure 3.
Output scaling is as shown in
ALIBRATION
calibration at the specified calibration interval listed in
is maintained over
its life. Calibration is a
the sensor module with
oxygen-free (or
, and then a specific concentration (or spa
n) gas. Two calibration
) are provided on the main
board as shown in
During gas sampling period that starts immediately
when calibration is initiated.
Temporary calibration applied.
Waiting for user to
the temporary calibration.
Failed calibration attempt.
Waiting for user to
acknowledge with either a re
-try or and exit.
ambient equilibration
period after successful
New calibration is applied.
During ambient equilibration period after failed
Old calibration is unchanged
.
Meaning of status LED blink patterns
during calibration.
mixture of oxygen and
nitrogen (see Table 9
) are required to calibrate the
recommended to ensure tha
t the
sensor is completely immersed in the
without applying higher than ambient pressure to it
.
A complete calibration kit that includes all the
required accessories in a convenient carrying case is available from
Mixture (by volume)
Recommended Accuracy
Comments
if supplied from l
beware of cooling the
20.9% oxygen
± 0.1 % oxygen
Calibration gas inaccuracy adds
directly to sensor’s specified
accuracy error.
Page 7 of 14
: Location of SPAN & ZERO Controls
the controller
’s powered 4 –
Output scaling is as shown in
) are required to calibrate the
sensor is completely immersed in the
required accessories in a convenient carrying case is available from
Comments
if supplied from l
iquid source
beware of cooling the
sensor.
Calibration gas inaccuracy adds
directly to sensor’s specified

OS-2 Oxygen Sensor
1/27/2021 Kele, Inc. • 3300 Brother Blvd. • Memphis, TN 38133 Page 8 of 14
5.2 ZERO CALIBRATION PROCEDURE
The Zero calibration procedure below MUST be done before the Span calibration.
The progress and status of the calibration process is indicated by the color and flash-state of the front cover status
LED (see Table 8).
Apply the nitrogen (zero) calibration gas to the sensor using a calibration adapter, following the instructions for the
calibration kit being used. Ensure that gas is flowing to the sensor, then press and hold the ’ZERO’ button (see
Figure 9) for 3 seconds until the front cover LED starts blinking YELLOW, indicating that gas sampling is in progress.
1. Ensure that the calibration adapter remains correctly seated and calibration gas continues to flow for the
2 minute sampling period.
2. At the end of the sampling period, the sensor’s status LED blinks GREEN if the calibration was successful
or RED if not.
3A. If successful (blinking GREEN):
The gas sampling completed successfully. Turn off the calibration gas flow, remove the calibration adapter
then press and hold the ‘ZERO’ calibration button until the LED blinks GREEN/YELLOW indicating that the
calibration gas has been removed, the calibration has been applied and the unit is in standby for two
minutes while the sensor re-equilibrates to the ambient atmosphere before normal operation resumes.
The calibration is complete when the status LED returns to steady GREEN.
OR
3B. If NOT successful (blinking RED):
The most likely cause of zero calibration sampling failure is insufficient gas flow or leaks around the
calibration adapter failing to completely immerse the sensor in nitrogen. Verify that calibration gas is still
flowing at the required rate (typically about 0.2 liters per minute) and the calibration adapter is properly
positioned.
The calibration sampling can be re-started while the LED is blinking RED by again pressing and holding
the ‘ZERO’ button until the LED blinks YELLOW, then return to step 1 above.
To exit the zero calibration routine preserving the original calibration: turn off the calibration gas flow
and remove the calibration adapter, then press and quickly release the ‘ZERO’ button. The status LED will
blink RED/YELLOW indicating that the calibration gas has been removed, the original calibration has been
restored and the unit is in standby for two minutes while the sensor re-equilibrates to the ambient
atmosphere before normal operation resumes. The original calibration is completely restored when the
status LED returns to steady GREEN.