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4. SEU (Main Sensor Unit)
The SEU (Main Sensor Unit) should be placed in a room where CO2 is likely to accumulate, a
room where CO2 is stored, like an area with CO2 beverages.
The large LCD displays the ambient CO2 concentration.
The SEU has “DIAG”, “AL1”, “AL2”,”AL3”, “CO2 CALI”, “RCFS” functions:
“DIAG” function executes communication tests between the SEU and RDU.
“AL1” is a fixed 5000ppm TWA.
“AL2” and “AL3” are two CO2 alarm levels. These alarm levels are adjustable.
- AL2 has CO2 level of: 5000, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%. (AL2 default is 1.5%)
- AL3 has CO2 levels of: 2.0%, 2.5%, 3.0%, 3.5%, 4.0%. (AL3 default is 3.0%)
“CALI” function allows the user to perform calibration, when necessary.
“RCFS” function allows the user to re-set the unit to the original factory settings.
When the RAD-0102-6 detects a CO2 TWA (average in 8 hours) value that exceeds 5,000ppm,
the AL1 (Red 1 LED) will blink and Relay 1 will be triggered.
When the CO2 TWA value drops below 5000ppm (with 5% hysteresis), AL1 (Red1 LED) will stop
blinking and Relay 1 will be inactive.
When the RAD-0102-6 detects a CO2 value that exceeds the AL2 CO2 level, AL2 (Red 2 LED)
will blink, the buzzer will sound and Relay 2 will be triggered.
When the CO2 value drops below the AL2 CO2 level, AL2 (Red 2 LED) will stop blinking, the
buzzer will stop and Relay 2 will be inactive.
If the CO2 concentration continues to rise and exceeds the AL3 CO2 level, AL2 (Red 2 LED) and
AL3 (Red 3 LED) will flash together. The tempo of the flashing and buzzer will increase. RAD-
0102-6 will latch after this event. When the CO2 value drops below the AL3 CO2 level and then
below the AL2 CO2 level, the flashing and buzzer will stop, but the Fault LED will remain flashing.
The RAD-0102-6 must be reset, by means of reset button of RAD-0102-6 (see item L in Section
2 SEU layout) or power cycle the unit.
The Power (Green LED) will light continuously when the power is normally supplied. If the device
is powered by a battery, the Power (Green LED) will flash and battery indicator will appear and
change with the battery voltage.
If the communication cable between the SEU & RDU is not connect well, the communication
cable is loose or disconnected from the (RJ45) connectors, the fault LED of SEU will blink as a
reminder for the user to reconnect the cable. If the communication cable is inserted into the
wrong port on RDU, after about one minute, the “Er7” will flash on the RDU LCD. Please plug
the cables into the correct ports on RDU and the unit will work normally.
