4.When using the GD-2A with normally closed initiating circuits, use the Com. and N.C. alarm relay connections.
5.See wiring diagram and information below for connections of the GD-2A.
UL 2075 Requirements - 12.4.1 Power supply leads provided for field connection shall not be less than 6 inches (152 mm) long, provided with strain relief, and shall be no smaller than 18 AWG (0.82 mm2). The insulation, when thermoplastic, shall not be less than 1/32 inch (0.8 mm) thick.
Exception No. 1: A lead is not prohibited from being less than 6 inches long when it is evident that the use of a longer lead results in damage to the insulation.
Exception No. 2: Solid copper leads as small as 26 AWG (0.13 mm2) are not prohibited from use when:
A.The current does not exceed 1 ampere for lengths up to 2 feet
(61 cm) and the current does not exceed 0.4 ampere for lengths from 2 feet (61 cm) up to 10 feet (3.05 m);
B.There are two or more conductors and they are covered by a common jacket, or the equivalent; and
C.The assembled conductors comply with the requirements of the Strain Relief Tests, Section 18.
12.4.2Leads provided for field connection to power limited signaling circuits, such as those employed for connection to remote signaling devices, shall not be smaller than 16 AWG (1.3 mm2), for a single conductor; 19 AWG
(0.65 mm2) for two or more conductors; and 26 AWG (0.13 mm2) for four or more conductors of a multi-conductor cable. The conductor shall be solid, bunch tinned stranded, or stranded copper. Stranded copper wire consisting of not more than seven strands shall be employed only for 18 AWG
(0.82 mm2) and larger conductors.
TYPICAL CONNECTION OF TWO GD-2A TO AN ALARM CONTROL PANEL
Alarm Control Panel | | | | | | |
N.O. initiating | | GD-2A | | GD-2A | E.O.L.R. |
| alarm | | | alarm |
circuit | | SPDT | | | SPDT | |
Battery back-up 12 or | | relay | | | relay | |
24VDC Power supply. | | Trouble | | | Trouble | |
Fuse or current limit at | POWER 12/24V | | POWER 12/24V | |
relay N.C. | | relay N.C. | |
1.0VA for each GD-2A | | | | |
| | | | | | |
6.The GD-2A uses a full wave bridge rectifier at its power input, so that it is independent of the polarity of the input power. It can operate on DC or AC voltages between 12 and 24 volts.
7.A switching regulator is used to efficiently match the wide input voltage range to the fixed, internal power system. As a result the power consumption is fairly constant at about 0.75 watts in normal operation, and 1.0 watt in alarm.
8.The alarm control panel zone inputs must be terminated with end of line resistors (E.O.L.R.), which are provided with the panel. The GD-2A does not have an internal audible sounder and must be connected to a UL Listed Fire Alarm/ Burglary Control Panel with a UL Listed audible device that provides at least 85 dB sound output.
POWER UP
WWARNING
When the unit is powered up it performs a self-test during which the green LED light blinks for a period of one and one half to two minutes. Afterwards, the green LED light will turn on continuously to indicate the unit is in normal operation (ARMED). If the self-test fails or the green LED light does not turn on continuously do not use. Failure to do so may adversely affect product performance and result in sickness or death.
When power is first applied to the detector, it will go through a warm-up period of one and one half to two minutes, during which alarms are inhibited. The green LED light will turn on and off during the delay period. The green light will turn on continuously (ARMED) afterwards to indicate the unit is in normal operation.
OPERATION
1.Once the GD-2A is operational (ARMED) the green light will be on continuously. If gas is detected the red LED (ALARM) turns on and the SPDT alarm relay activates to indicate the alarm condition.
2.In the configuration, as shipped from the factory, the GD-2A is self-restoring. When the air clears of gas, the red light turns off and the relay switches to its normal state. A jumper wire on the circuit board can be clipped to allow the unit to latch in upon alarm. Once latched in, power will need to be interrupted to un-latch the alarm condition.
•The GD-2A can be modified, either before or after installation, to have a latching output. Pull off the cover and locate the jumper wire labeled “CLIP FOR LATCH IN” on the printed circuit board in the upper right hand side. Clip or cut this jumper wire and separate the wire ends. Now the unit will stay in alarm (once gas has exceeded the pre-set threshold) until the power is interrupted. When replacing the cover, make sure the lights line up with their access holes.
3.The GD-2A has a supervisory circuit of critical functions. A trouble condition, due to failure of a non-reliable component, results in both lights switching on and off and the normally closed trouble relay opening. A power failure also causes the trouble relay to open.
ALARMS
WWARNING
Immediately exit any environment if there is an alarm condition on the detector.
Failure to do so may result in sickness or death.
The final alarm is determined by the configuration of the control panel, with the GD-2A only switching its relay to actuate the panel. Do not connect the GD-2A to Fire Alarm Circuits, or Burglar Alarm or other signals. The illumination of the red (ALARM) light on the GD-2A indicates the alarm condition. When an alarm occurs immediately evacuate the premises and seek assistance.
In addition to the methane (natural gas) and propane (LP) gas that it is designed to detect, the GD-2A can also be affected by a broad range of combustible gases. Some of these that may cause an alarm are: alcohols, ammonia, cleaning solvents, paint thinner, gasoline vapors, and aerosol propellants. Aerosol cans such as hair spray usually contain a combustible gas. Always make sure that there is adequate ventilation when you use these products. Proper location, not in kitchens or bathrooms, will minimize alarms due to normal use of household products.
WWARNING
This detector will only indicate the presence of combustible gas at the sensor. Combustible gas may be present in other areas. Accommodation spaces should be well ventilated when household cleaning supplies or similar contaminants are used.
TROUBLE INDICATOR
The trouble signal is determined mostly by the configuration of the alarm panel, with the GD-2A trouble relay only providing an open circuit for actuation. A failure of the gas-sensing element will result in both lights turning on and off and the trouble relay opening. Failure of power supplies in the GD-2A or a lack of power to the detector will result in the trouble relay opening. The most common expected trouble would be a break in the wiring between the panel and the GD-2A. When a trouble signal occurs call the alarm panel installer for assistance.
WWARNING
Do not cover or obstruct visual alarm LED. Doing so may adversely affect product performance and result in sickness or death.
MAINTENANCE
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.
The GD-2A does not require regular maintenance. The unit uses a self-purging semi-conductor sensor that has a long life expectancy (7-10 year life). All service and repair of the GD-2A are to be performed by 3M. 3M does not sanction any third-party repair facilities.
TESTING
Once the unit is fully operational (the green light is on steady), test the unit by directing gas from an unlighted butane cigarette lighter into the detector near the left hand side through one of the vent holes. It will be necessary to hold the lighter valve open for several seconds. The red light (ALARM) will turn on, the alarm relay switches, and any devices connected should activate. The detector should be tested regularly by using gas from an unlit cigarette lighter, as detailed above.
CLEANING
The GD-2A should be cleaned using the soft brush attachment of your vacuum cleaner. The GD-2A should be tested after cleaning to ensure the unit is operating normally.
SENSOR POISONS
The gas sensor tip in the detector is designed with extreme sensitivity to the environment. As a result, the gas sensor may deteriorate 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.
3M FIXED GAS DETECTION PRODUCTS LIMITED WARRANTY
3M warrants the GD-2A gas detector will be free from defective materials and workmanship for a period of two (2) years from date of manufacture (indicated on the inside cover of the GD-2A), provided it is maintained and used in accordance with 3M instructions and/or recommendations. If any component becomes defective during the warranty period, it will be replaced or repaired free of charge, if the
unit is returned in accordance with the instructions below. This warranty does not apply to units that have been altered or had repair attempted, or that have been subjected to abuse, accidental or otherwise. The above warranty is in lieu of all other express warranties, obligations or liabilities. THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE ARE LIMITED TO A PERIOD OF TWO (2) YEARS FROM THE PURCHASE DATE. 3M shall not be liable for any incidental or consequential damages for breach of this or any other warranty, express or implied, arising out of or related to the use of said gas detector. Manufacturer or its agent’s liability shall be limited to replacement or repair as set forth above. Buyer’s sole and exclusive remedies are return of the goods and repayment of the price, or repair and replacement of non-conforming goods or parts.
FOR MORE INFORMATION
In United States, contact:
Website: www.3M.com/OccSafety
Technical Assistance: 1-800-243-4630
For other 3M products:
1-800-3M-HELPS or 1-651-737-6501
