Maintenance

Selecting Fan Minimum Run Time – “Frr”

To select the Fan Minimum Runtime setting, in normal mode, press the Next button twice to get to “Con” or the Configuration menu. Then press the Enter button to enter the Con menu. The ninth selection is the “Frr” or Fan Minimum Run Time. Press Next eight times to get to “Frr” then press Enter. If the runtime is “OFF” (disabled) press Next to change it to 3, 5, 10 or 15 minutes (flashing) then press Enter to confirm the change (solid) and press Enter again to return to “run” in the Con menu. Press Next until “End” is displayed then press Enter to return to normal operation.

Selecting 4-20mA Output Option – “420”

To select the 4-20mA Output Option, in normal mode, press the Next button twice to get to “Con” or the Configuration menu. Then press the Enter button to enter the Con menu. The tenth selection is the “420” or 4-20mA Output Option. Press Next nine times to get to “420” then press Enter. If the 4-20mA is “On” press Next to turn it to “OFF” (flashing) then press Enter to confirm the change (solid) and press Enter again to return to “420” in the Con menu. Press Next until “End” is displayed then press Enter to return to normal operation.

Onboard Diagnostics

The 3M™ Macurco™ GD-6 Combustible Gas Detector monitors all critical functions of the unit through software diagnostics that continuously test and verify unit operations. If a problem is found, the unit will switch to a fail-safe/error mode or trouble condition. In this error mode, the Fan and Alarm relays will be activated; the 4-20mA current loop will go to 24mA and the LED light will Flash Green. This is a safety precaution. To clear this mode, simply turn off power to the unit for a few seconds, or press the TEST switch (inside the unit). This will cause the unit to restart the 1 minute self-test cycle.

The 4-20mA signal can be used for troubleshooting:

•0mA is most likely a connection problem

•4-20mA is normal gas reading range (0-50% LEL)

•24mA indicates a Trouble condition

Error Codes

•t01 Sensor is missing

•t02 Temperature compensation failed

•t04 Bad EEPROM checksum

•t08 Sensor is shorted

•t10 Bad EEPROM

•t20 Bad factory calibration

•t40 Factory calibration was not done

•t80 SDADC reading failed

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 3M Macurco for service, as noted in 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 a direct spray from aerosols such as paints, silicone vapors, etc., or to a high density of corrosive gases (such as hydrogen sulfide, sulfur dioxide) for an extended period of time.

The 3M™ Macurco™ GD-6 Combustible Gas Detector does not require regular maintenance other than cleaning. The unit uses a long life pellistor sensor that has a 5+ year life expectancy. All maintenance and repair of products manufactured by 3M are to be performed at the appropriate 3M manufacturing facility. 3M does not sanction any third-party repair facilities.

WWARNING

Do not disassemble unit or attempt to repair or modify any component of this instrument. This instrument contains no user serviceable parts, and substitution of components may impair intrinsic safety, which may adversely affect product performance and result in sickness or death.

CAUTION

•Avoid the use of harsh cleaning materials, abrasives and other organic solvents. Such materials may permanently scratch the surfaces and damage the display window, labels, or instrument housing.

Cleaning

Cleaning of the external surfaces is best carried out using a damp cloth with a mild detergent or soap. Vacuum under the cover with soft brush to remove dust or contamination.

Testing

WWARNING

Using a certified gas with a concentration other than the one listed for this instrument and sensor when conducting a calibration or calibration verification test (bump test) will produce inaccurate readings. This means that higher levels of the gas being monitored may be present and could result in overexposure and cause sickness or death. For proper use, see supervisor or User Instructions, or call 3M in U.S.A., 1-800-243-4630. In Canada, call Technical Service at 1-800-267-4414.

General

There are multiple ways to test the 3M™ Macurco™ GD-6 Combustible Gas Detector after installation: Operation Test, Manual Operation Test, Combustible Gas Test and Quick Gas Test. The 3M™ Macurco™ GD-6 Combustible Gas Detector also has the ability to test itself automatically and does so every 2 1/2 minute cycle. If the unit detects an improper voltage or inoperable component it will default into Error mode. In Error mode, the unit will Flash Green and both the fan & alarm relay will be actuated. Check that the 3M™ Macurco™ GD-6 Combustible Gas Detector OPERATING LED type light is illuminated, continuously. If not, do not proceed with the tests. If the unit is in error mode contact your local representative or 3M Macurco Technical Service representative for information on resolving the problem.