User Manual

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precaution. To clear this mode, simply turn off power to the unit for a few seconds, or push the ENTER/TEST switch (inside the unit).
This will cause the unit to restart the 1 minute self-test cycle.
The 4-20 mA signal can be used for troubleshooting:
 0 mA is most likely a connection problem
 4-20 mA is normal gas reading range (0-50% LEL)
 24 mA indicates a Trouble condition
Error Codes
 t01 Sensor missing
 t04 EEPROM bad checksum
 t08 Sensor is shorted
 t10 Bad EEPROM
 t20 Bad calibration
 t40 Factory calibration failure
 t80 Read ADC failure
 t100 Under range
 t200 Sensor expired
NOTE: For trouble codes over 080 the display will alternate between t_1 and t00 for t100 and between t_2 and t00 for t200.
If the error mode repeats frequently, check for continuous power and proper voltage. If power is not the problem and a unit has
repeating error conditions, it may need to be returned to Macurco for service, per these User Instructions.
If the error mode indicates “Sensor expired” see the Sensor Life Reset section of these User Instructions.
Sensor Poisons
The gas sensor in the detector is designed with extreme sensitivity to the environment. As a result, the sensing function may be
deteriorated if it is exposed to silicones, such as the common oil and lubricants with silicon compounds used as additives in machinery,
halogen compounds, which are used in fire extinguishers and Freon used in refrigerants, organo-metallic compounds, sulfur
compounds, chlorine compounds, acetylene, olefins or high concentrations of combustible gas.
MAINTENANCE
The GD-12 is low maintenance. The unit uses a long life pellistor sensor that has a 5+ year life expectancy. The detector’s performance
should be tested regularly by using gas as detailed in the Testing and Field Calibration sections. All other maintenance and repair of
products manufactured by Macurco are to be performed at the appropriate Macurco manufacturing facility. Macurco does not sanction
any third-party repair facilities.
End-of-life Signal