∙It is the responsibility of the installer to install conduit seals where necessary, and to design conduit runs to ensure that condensation does not accumulate and collect inside the enclosure.

2.1.2 Cable choice and guidelines

Radio Frequency Interference (RFI) can be caused by nearby electrical devices (transformers, high voltage equipment) as well as handheld communications devices/radios, which when activated, may impede the proper functioning of the transmitter and sensor. Selecting the right instrumentation cable and making proper grounding connections within the junction box will reduce or eliminate interference. Visible symptoms of Radio Frequency Interference (RFI) include inconsistent, incorrect and erratic LEL and PPM readings.

Important Wiring Guidelines

Fire and gas detection instruments are an important part of a safety alarm and shutdown system. The system is composed of:

∙detection instruments

∙customer connected equipment

∙wiring

Net Safety designs and manufactures its detection equipment under rigid quality control management systems and makes every effort to design for the harshest of industrial environments. The other components of the system – the customer-connected equipment and wiring – are also important contributors to the overall quality and performance of the safety system.

It is important to implement wiring that ensures the reliability and integrity of the safety system. Field wiring practices and the choice of cable type specified vary from project to project. Poor practices and choices are often found to be the source of unwanted system disruptions. Radio Frequency Interference (RFI) and Electro-Magnetic Interference (EMI) are usually very powerful disruptive forces in industrial facilities and these forces act upon the system through the wiring.

Follow the wiring specifications and guidelines in this manual carefully. The cable used should be a very high quality instrument grade, certified for the application conditions, consisting of a rugged protective outer jacket, an overall electrical shield of fine braided copper or metallic foil, and internal pairs or triads of foil shielded copper wire of suitable gauge for the power conducted over the specified length.

The shields must be electrically continuous from the instrument junction box through other junction boxes and finally to the connected equipment. The shield must be connected to a suitable ground sink as specified in the instrument manual in order to protect the system from electrical disturbances.

Recommended cable and guidelines

The type of cable and shielding practices are especially important when sensor is separated from transmitter via junction box. Net Safety recommends using CSA armored instrumentation cable (ACIC 2PR 16AWG, 300V, ISOS, PVC) when rigid (steel) conduit is not used. See Figure 5. This cable should be used between the PLC/PANEL/DCS and the Millennium II Transmitter, as well as between the Millennium II Transmitter and junction box.

Additional notes:

In general, communication cables and power cables should not run in parallel for any significant length, and should not be carried in the same cable tray. Through inductance, high currents in power cables can induce significant ‘noise’ in communication cables running parallel alongside power cables.

See cable preparation procedure on next page.

11

MAN-0076 Rev 05 Millennium II December 07, 2012

Net Safety Monitoring Inc

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Emerson M21, M22 user manual Cable choice and guidelines, Important Wiring Guidelines
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M22, M21 specifications

The Emerson M21 and M22 are advanced industrial controllers designed to enhance process automation and operational efficiency in various industries. Emerson, a leader in automation technology, introduced these models to meet the growing demands for precision, reliability, and connectivity in today’s fast-paced industrial environments.

One of the standout features of the M21 and M22 controllers is their robust processing power. They are equipped with high-speed processors that enable rapid data processing and real-time decision-making. This capability allows users to respond promptly to changing process conditions, ensuring optimal performance and minimizing downtime.

The M21 and M22 offer versatile connectivity options, supporting various communication protocols such as Ethernet, Modbus, and TCP/IP. This extensive connectivity facilitates seamless integration into existing systems, allowing for easy collaboration between devices across different platforms. Users can monitor and control processes from virtually anywhere, providing flexibility and convenience.

Scalability is another essential characteristic of the M21 and M22. These controllers can easily adapt to growing operational demands, enabling businesses to expand their automation solutions without the need for complete overhauls. Whether you're running a small system or a large, complex operation, these controllers can scale to meet your needs.

Furthermore, Emerson has incorporated advanced diagnostic and predictive maintenance features into the M21 and M22 models. These technologies leverage data analytics to predict potential failures before they occur, allowing users to take proactive measures. This not only minimizes unexpected downtime but also extends the lifespan of equipment, contributing to overall cost savings.

In terms of user interface, the M21 and M22 come with intuitive software that provides easy navigation and configuration. The interface is designed to be user-friendly, reducing the learning curve for new operators and allowing for efficient setup and management of processes.

Finally, both controllers are built with a focus on reliability and durability, making them suitable for various industrial environments, including harsh or demanding settings. Their robust design ensures consistent performance, even in challenging conditions.

In summary, the Emerson M21 and M22 controllers represent cutting-edge solutions in industrial automation, offering high processing power, flexible connectivity, scalability, advanced maintenance features, user-friendly interfaces, and robust design. Companies looking to enhance their automation capabilities will find these controllers to be valuable assets in achieving operational excellence.
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