Instruction Manual

1. Product Overview

The Macurco 12-series are line voltage powered (100-240VAC), dual relay gas detectors, controllers, and transducers. This electronic detection system is designed to measure the concentration of various gases, specifically Nitrogen Dioxide (No2), and provide feedback and automatic control. It helps reduce gas concentrations in environments such as parking garages, maintenance facilities, or other commercial applications. The TX-12-ND model features an internal switching power supply compatible with 100-240VAC and 50-60Hz power sources. It offers selectable 4-20mA output, a buzzer, and digital display options for comprehensive gas monitoring and control.

Figure 1: Front view of the Macurco TX-12-ND Gas Detector. The device is white with a black display panel showing "TX-12 GAS DETECTOR" and a digital '0'. A power indicator and power symbol are visible on the top left. The side of the unit shows "ND" indicating Nitrogen Dioxide detection.

2. What's in the Box

Upon opening the package, verify that all components are present and undamaged. The standard package for the Macurco TX-12-ND includes:

• Macurco TX-12-ND Gas Detector Unit
• Instruction Manual (this document)

Note: Additional mounting hardware or accessories may be sold separately.

3. Key Features

• Selectable Relay Actuation Levels: Customize alarm thresholds for specific gas concentrations.
• Multiple Outputs: Includes a fan relay, alarm relay, and a 4-20mA current loop for integration with building management systems.
• Compliance: Meets Uniform Building Code for enclosed garages and OSHA standards for gas exposure, ensuring safety and regulatory adherence.
• Configurable Controls: Features a buzzer for audible alerts, a digital display for real-time readings, latching relay options, adjustable relay delay, and minimum runtime settings.
• Easy Mounting: Designed to mount conveniently on a standard 4" x 4" electrical box.

4. Setup and Installation

Proper installation is crucial for the accurate and safe operation of the TX-12-ND gas detector. It is recommended that installation be performed by a qualified electrician in accordance with local electrical codes and regulations.

4.1 Mounting Location

• Choose a location where the gas detector can accurately monitor the air quality, typically near potential sources of Nitrogen Dioxide or in areas where gas accumulation is likely.
• Avoid mounting near ventilation outlets, doors, windows, or in direct sunlight, which can affect sensor readings.
• The unit is designed to mount on a standard 4" x 4" electrical box.

4.2 Electrical Connection

The TX-12-ND operates on line voltage (100-240VAC, 50-60Hz). Ensure the power supply is disconnected before making any electrical connections.

• Connect the AC power supply to the designated terminals on the unit. Refer to the wiring diagram provided inside the unit's cover for precise connections.
• If utilizing the 4-20mA output, fan relay, or alarm relay, connect these to your building management system or control devices as required.
• Ensure all connections are secure and properly insulated.

4.3 Initial Power-Up

After installation and wiring are complete, restore power to the unit. The device will typically undergo a self-calibration or warm-up period, indicated by the digital display. Allow sufficient time for the unit to stabilize before assuming normal operation.

5. Operating Instructions

The Macurco TX-12-ND is designed for continuous monitoring. Once powered, it will begin detecting Nitrogen Dioxide levels in the environment.

5.1 Digital Display

The front digital display shows the current concentration of Nitrogen Dioxide. The unit of measurement (e.g., PPM - parts per million) will be indicated or implied by the device's configuration.

5.2 Alarm and Relay Operation

The device features configurable alarm thresholds. When the detected gas concentration exceeds a preset level, the following actions may occur:

• Audible Alarm (Buzzer): The internal buzzer will sound to alert occupants.
• Alarm Relay Activation: The alarm relay will activate, which can be wired to external alarm systems, lights, or other warning devices.
• Fan Relay Activation: The fan relay will activate, typically used to control ventilation systems to reduce gas concentrations.
• 4-20mA Output: The 4-20mA current loop provides a continuous analog signal representing the gas concentration, allowing for integration with building management systems for data logging and remote monitoring.

Relay delay and minimum runtime settings can be configured to prevent nuisance alarms and ensure effective ventilation cycles.

5.3 Configuration (Advanced)

Advanced configuration, including setting alarm points, relay behaviors (latching/non-latching), and output scaling, is typically accessed via internal jumpers or a configuration menu. Refer to the detailed technical manual (if separate) or internal diagrams for specific instructions on these adjustments. It is recommended that only qualified personnel perform these configurations.

6. Maintenance

Regular maintenance ensures the longevity and accuracy of your Macurco TX-12-ND gas detector.

6.1 Cleaning

• Periodically wipe the exterior of the unit with a soft, damp cloth.
• Do not use abrasive cleaners, solvents, or harsh chemicals, as these can damage the housing or internal components.
• Ensure the ventilation openings are clear of dust and debris.

6.2 Calibration

Gas detectors require periodic calibration to maintain accuracy. The frequency of calibration depends on environmental conditions and regulatory requirements. Consult the manufacturer's recommendations or a certified service technician for calibration procedures. Typically, Nitrogen Dioxide sensors require calibration annually or as specified by local codes.

6.3 Sensor Replacement

Gas sensors have a finite lifespan. If the unit indicates a sensor fault or fails calibration, the sensor may need replacement. This procedure should only be performed by trained personnel.

7. Troubleshooting

This section provides basic troubleshooting steps for common issues. For more complex problems, contact technical support.

8. Specifications

9. Safety Information

The Macurco TX-12-ND is designed to enhance safety by monitoring gas levels. Adhere to the following safety guidelines:

• This device meets Uniform Building Code for enclosed garages and OSHA standards for gas exposure. However, it is not a substitute for proper ventilation and safety protocols.
• Always ensure adequate ventilation in areas where gas detection is critical.
• Do not paint the unit, as this can obstruct sensor openings and impair performance.
• In case of an alarm, follow your facility's emergency procedures for gas leaks or high gas concentrations.
• Only qualified personnel should install, service, or calibrate the unit.

10. Warranty and Support

Macurco products are manufactured to high-quality standards. For information regarding product warranty, technical support, or service, please contact Macurco customer service or visit their official website. Keep your purchase receipt as proof of purchase for warranty claims.

Manufacturer: Macurco

Website: www.macurco.com (Note: This is a placeholder URL, please verify the actual manufacturer's website.)