INSTALLATION

UM344-2

B.RTD/Ohm Sensor-to-Transmitter Extension Cable

The Transmitter will compensate for the effect of lead wire resistance for 3 and 4-wire RTD's and for an Ohm (potentiometer) sensor when a 3-wire input connection is used. Input connections may be made with copper wire.

1) Cable Recommendation for RTD: Multi-conductor high temperature cable, overall braid shield with three copper TFE insulated conductors and TFE wrapped jacket. Wire size

should be 24 to 16 (AWG).

2)Cable Recommendation for Ohm: Multi-conductor standard temperature instrumentation grade cable, overall braid shield, PVC insulated three copper conductors with PVC jacket. Wire size should be 24 to 16 (AWG).

C.Millivolt Sensor-to-Transmitter Extension Cable

Cable Recommendation: Multi-conductor standard temperature instrumentation grade cable, overall braid shield, PVC insulated twisted pair copper conductors with PVC jacket. Wire size should be 24 to 16 (AWG).

4.3.10 2-Wire RTD Accuracy Limitation

The use of a 2-wire RTD requires a careful analysis of the effects of extension lead wire resistance that can cause an error in temperature measurement.

A 2-wire RTD may be used when the resistance of the run of lead wire may be considered as an additive "constant temperature error" and the changes in lead resistance due to ambient temperature changes may be ignored.

The RTD sensor element is approximately one inch in length. The platinum wire at each end of the RTD is terminated in insulated copper lead wire. The lead wire extends beyond the sensor probe's protective metal sheath to a distance specified by the user. The lead wires are terminated in the Transmitter's terminal compartment when the probe assembly is mounted to the Transmitter. On a remote mounted Transmitter, the lead wires are terminated in the probe's connection head and extended by a second set of wires to the Transmitter.

The extension lead wire resistance is the sum of the resistances of both copper wires connecting the RTD element to the Transmitter.

Extension lead wire resistances will add to the resistance of the RTD causing a permanent somewhat higher temperature reading than actually exists at the RTD location. For example, if a 1 degree offset error is acceptable, then the maximum #24 AWG extension lead wire length permissible would be calculated for a 100 Ohm RTD (DIN Curve) as follows:

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September 1995

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Siemens UM344-2 user manual 10 2-Wire RTD Accuracy Limitation
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UM344-2 specifications

The Siemens UM344-2 is a cutting-edge industrial controller designed to meet the demands of modern automation and control systems. This powerful device is specifically developed for use in various applications, including manufacturing, process control, and machinery integration. The UM344-2 stands out for its versatility and robust performance in harsh industrial environments.

One of the main features of the Siemens UM344-2 is its high processing speed, which allows for real-time data processing and decision-making. The controller utilizes advanced microprocessor technology, ensuring quick response times and efficient operation. Its architecture supports multitasking, enabling it to manage multiple processes simultaneously without compromising performance.

The UM344-2 features a modular design, which provides flexibility in configuration and scalability. Users can easily add or remove modules to tailor the system to specific application requirements. This adaptability is beneficial for businesses that need to scale their operations or adjust to changing production demands. The controller is compatible with a variety of I/O modules, allowing for seamless integration with other equipment and systems.

In terms of connectivity, the Siemens UM344-2 supports various communication protocols, including Profibus, Profinet, and Ethernet. This versatility ensures smooth data exchange between the controller and other devices in the automation ecosystem, facilitating comprehensive monitoring and control. The inclusion of these communication standards enhances interoperability and allows for the integration of legacy systems with newer technology.

The Siemens UM344-2 is equipped with advanced diagnostic tools, which enable users to monitor system performance and detect potential issues in real-time. This feature reduces downtime and maintenance costs by allowing for proactive management of the system. The controller also supports remote access capabilities, enabling technicians to troubleshoot and configure systems from off-site locations.

Safety is a critical consideration in industrial environments, and the UM344-2 is designed with this in mind. It incorporates safety-certified features, ensuring compliance with international safety standards. Users can implement safety functions directly within the controller, streamlining system design and reducing the need for external safety components.

Overall, the Siemens UM344-2 exemplifies the fusion of technology and practical application, making it an essential component for businesses looking to enhance their automation processes. With its high performance, flexibility, and focus on safety, the UM344-2 is a reliable choice for industries aiming for efficiency and innovation in their operations.
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