Kele OS-2 Gas and Specialty Sensors Instructions
- June 5, 2024
- Kele
Table of Contents
OS-2 Wiring and Calibration Instructions
Operation
The OS-2 has no power switch and is operational whenever it has su! cient operating power. Operational status is indicated by a pair of LEDs on the front cover as shown in the table below:
Installation
The OS-2 is suitable for indoor use only. Mount the unit as close to the source of potential refrigerant leaks as possible. Some recommended considerations are as follows:
- Mount the unit with the sensor pointing down.
- Mount the unit in a location with low vibration. Strong vibration may cause a change in the condition of the internal membrane.
- The sensor should be mounted 3’ to 5’ (0.9 to 1.5m) from the door in equipment rooms or 1’ (0.3m) above the door in refrigeration pits.
- The OS-2 should cover about 1000-1500 square feet with adequate air movement.
- Mount at least 5’ (1.5m) from the exhaust fan.
- Verify operation yearly.
Note: Make all connections in accordance with national and local codes.
Not recommended for MRI rooms.
OS-2 Operation Procedure
ALARM Relay Connections
The OS-2 has an SPDT, dry contact relay output that is accessed at the three- position screw terminal.
- The top terminal is the relays NO contact,
- The middle terminal is COM (common).
- The bottom is the relays NC contact.
Potential Effects of Oxygen-Deficient Atmospheres
O2 content (%)| | Effects and Symptoms (at atmospheric pressure)
20.9%| | Normal air
19.50%| Minimum permissible oxygen level
15 – 19%| Decreased ability to work strenuously. May induce early
symptoms in a person with coronary, pulmonary, or circulatory problems
12 – 14%| Respiration increases during exertion
10 – 12%| Poor judgment, lips turn blue
8 – 10%| Mental failure, fainting, unconsciousness
6 – 8%| 4-5 minutes -recovery with treatment 6 minutes – 50% fatal 8
minutes – 100% fatal
4 – 6%| Coma onset in 40 seconds
Power Connection:
Use the Wiring Diagram (Figure 5) for reference with the following descriptions. The OS-2 can be powered from 20 to 30 volts AC or DC. The operating power is connected to the four-position terminal connector at the positions marked PWR+ and PWR- on the circuit board. The polarity of the power inputs is only relevant when DC voltage is used to power the unit; if DC voltage is hooked up in reverse polarity the unit will not power up, but no damage to the controller will occur. Because the OS-2 uses a non-isolated power supply, a separate power transformer for each unit is the safest con” guration when the analog outputs are used.
Analog Output Connection:
The OS-2 has an analog output option: the analog output is accessed at the 4-position terminal block. Connect to positions labeled OUT 1+ and OUT 1-. The analog output can be con” gured as voltage or current (refer to Table 3 in the Con” during the Controller section for more information). If the 4-20mA current output is selected, the current will ow out of the terminal marked ‘+’ and return through the terminal marked ‘-’. This is not a loop-powered device: do not attempt to power the OS-2 through the 4 – 20mA (analog output) connection as this will void the warranty and likely damage the unit.
OS-2 Oxygen Sensor
Parameter| Value|
Comments
Measurement Range| 0 – 25.0%|
Resolution| 0.1%|
Operating Condition
| Atmospheric Pressure: 811hPa – 1216hPa| No condensation
Temperature: 5°C – 40°C|
Relative Humidity: 10 – 90% RH|
Accuracy| ±1.5%| Of full scale
Life Expectancy| AirSense OS-25: 5 years| Life expectancy is shortened with
exposure to high temperatures, low pressures, extremely dry environments, and
high concentrations of O2.
AirSense OS-50: 10 years|
Storage Temperature| -20°C – +60°C| Storage at low temperature (in a
refrigerator) and low oxygen concentration will prolong the life expectancy of
the O2 sensor. The sensor will freeze at temperatures below -20°C and will not
function until thawed. Exposure to temperatures above 60°C will damage the
sensor.
Relay Outputs| 1 SPDT dry contact| Rated for 240 VAC, 1A
Alarm Threshold| 1% – 24%| Default: 19.5%
Analog Output| See Table 3| Jumper Selectable
Voltage Output| Minimum Load Impedance (Rmin)| Rmin = 100kΩ
Current Output| Maximum Loop Imped- ance (Rmax)| Rmax = 500Ω
Power| 20 – 30 V (AC/DC)|
Power Consumption| 0.3A rms|
Current Loop Connection
The 4 – 20 mA current loop output appears at the screw terminal connector
labeled ‘OUT+’ and ‘OUT -’, located below the power connector and the relay
connector.
The OS-2 is NOT a loop-powered device. Attempting to power the device through
the current loop connector will void the warranty and likely damage the unit.
The loop current! ows out of the upper terminal marked ‘+’ and returns to the
lower terminal marked ‘-‘.
Because the OS-2 uses a non-isolated power supply, a separate power
transformer for each unit is the safest con” guration when the current loop
output is used. The current-loop outputs from multiple units powered from the
same transformer must be connected to fully isolated inputs to avoid
potentially destructive current loops.
SETPOINT
OS-2 Series O2 Monitor
REV 1/12/11