3M GD-6 User Manual

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If you have any doubts about the applicability of the equipment to your job situation, consult an Industrial Hygienist or call 3M

Macurco Technical Service at 1-800-243-4630. In Canada, call 1-800-267-4414.
General Information

The 3M™ Macurco™ GD-6 Combustible Gas Detector helps combustible gas detection and automatic exhaust fan control for 

automotive maintenance facilities, enclosed parking garages, warehouses with forklifts, etc. The GD-6 can be used with 12VDC 

or 24VDC N.O. (fire/security) panels.
Location

A 3M™ Macurco™ GD-6 Combustible Gas Detector is usually located in areas where there is potential for gas leaks; where 

there are gas appliances, areas through which gas pipes pass, where batteries are being stored or charged, etc. 

Do noT mount 

the 3M™ Macurco™ GD-6 Combustible Gas Detector in a corner. 

Do noT mount the 3M™ Macurco™ GD-6 Combustible Gas 

Detector where the normal ambient temperature is below below 0°F or exceeds 125°F (-18°C or above 52°C). If the target gas

is lighter than air; natural gas (Methane) or Hydrogen (H

2

), mount the 3M™ Macurco™ GD-6 Combustible Gas Detector high 

on a wall about one foot down from the ceiling. If the target gas is heavier than air; propane (LP), mount the 3M™ Macurco™ 

GD-6 Combustible Gas Detector on a wall or column one foot above the floor. Use the same spacing as for smoke detectors-30 

foot centers, 900 square feet per detector.
note: alcohols, ammonia, cleaning solvents, paint thinner; gasoline vapors and aerosol propellants (aerosol cans such as hair 

spray usually contain a combustible gas) may cause alarms.

•  ETL Listed to UL 61010-1
•  The 3M™ Macurco™ GD-6 Combustible Gas Detector can be bump-tested with the FTK with 10% LEL Methane,  

10% LEL Propane or 10% LEL Hydrogen gas, regulator and calibration hood.

•  The 3M™ Macurco™ GD-6 Combustible Gas Detector can be field calibrated using 10% LEL Methane, 10% LEL

Propane or 10% LEL Hydrogen gas, regulator and calibration hood.

•  The 3M™ Macurco™ GD-6 Combustible Gas Detector is a low level meter capable of displaying from 0-50% LEL EX
•  Selectable fan and alarm relay activation
•  5A SPDT fan relay controls starters of exhaust fans
•  0.5A N.O. or N.C. alarm relay connects to warning devices or control panels
•  4-20mA current loop
•  The 3M™ Macurco™ GD-6 Combustible Gas Detector mounts on a standard 4x4 electrical box and becomes cover  

for the box

•  Supervised system: any internal detector problem will cause the fan & alarm relay to activate
•  Optional calibration kit is available. One screw allows access for calibration

•  Power: 3W (max) from 12 to 24VAC (Volts Alternating Current) or 12 to 48VDC (Volts Direct Current)
•  Current @ 24VDC: 75mA in alarm (two relays), 50mA (fan relay only) and 23mA stand by
•  Shipping Weight: 1 pound (0.45 kg)
•  Size: 4 1/2 x 4 x 2 1/8 in. (11.4 x 10.2 x 5.4 cm)
•  Color: dark gray
•  Connections: plugs/terminals
•  Mounting box: (not included) 4x4 electric
•  Fan relay: 5A, 240VAC, pilot duty, SPDT
•  Fan relay actuation: selectable at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 (default), 11, 12, 13, 14, 15, 16, 17, 18, 19, 20% LEL
•  Fan Delay Settings of 0, 1, 3 (default), 5 and 10 minutes
•  Fan Minimum Run Time settings are OFF (default), 3, 5, 10 or 15 minutes
•  Alarm relay: 0.5A 200V, 10VA
•  Alarm relay actuation: selectable N.O. default or N.C.
•  Alarm relay settings: OFF, 5, 10, 15, 20 (default), 25% LEL
•  Current loop, 4-20mA for 0-50% LEL
•  Operating environ: 0°F to 125°F (-18°C to 52°C). 10 to 90% RH

The following instructions are intended to serve as a guideline for the use of the 3M™ Macurco™ GD-6 Combustible 

Gas Detector, Controller and Transducer. It is not to be considered all-inclusive, nor is it intended to replace the policy and 

procedures for each facility. 

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This detector monitors for the presence and concentration level of certain specified airborne gases. Misuse may produce 

an inaccurate reading, which 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, User Instructions or call 3M in U.S.A.,  

1-800-243-4630. In Canada, call Technical Service at 1-800-267-4414.