From the Sensor to the Controller: Reliable Signal Transmission in Confined Spaces
November 1, 2017
The needs of system operators have changed drastically – there is a trend for higher packing density in the control cabinet and consequently ever narrower components. With “Termitrab complete”, Phoenix Contact is now launching the world’s narrowest surge protection for MCR technology (measurement, control, and regulation) – the narrowest devices are just 3.5 mm wide (Figure 1 High safety for persons and the environment – ensured by a comprehensive surge protection with minimal space requirements).
It is a characteristic of the water and wastewater treatment industry to have numerous networked processes – between field level, management level, and subsections that are usually far apart. The requirements on planners, installers, and operators of the systems are increasing steadily. Failsafe concepts are becoming more important due to the increasing implementation of electromechanical and electronic components, systems and solutions, as well as the networking between them.
Megatrends in the market
Overvoltage concepts play an important role. Two major factors are at play here: high system availability and the resulting security of supply for the population.
As in other infrastructure fields, the trend towards implementing ever smaller and more compact components is also quite noticeable in the field of water and wastewater treatment. To optimize the costs of overall control cabinet manufacturing, the surge protective devices should take up as little space as possible. The goal is to centralize numerous service functions – such as system monitoring – in the control room. To operate the system safely from an EMC perspective, surge protective devices are implemented in large systems.
Protection in a confined space
Numerous channels often have to be housed within a small area in order to transmit analog or digital signals. Since space is becoming increasingly valuable, Phoenix Contact’s new Termitrab complete product range has width’s of only 3.5mm to 6mm. The power dissipation has been minimized significantly as well, due to the decoupling resistors in the protective circuits. This feature also aims to satisfy the demand for installing more devices in increasingly smaller spaces.
The lightning protection standards recommend regular inspection of protective devices. This is only possible through visual examination. The Termitrab complete product range features a status indicator that displays an overload of the surge protection directly on the device. Since no additional power is needed for this indicator, the protective device also displays the fault continuously during an overload. If this information is to be sent to the control room or other alarming method, the optionally available “remote signaling modules” ensure the necessary data transmission. (Figure 2 Integrated status indicator: Thanks to the surge protection components of Termitrab complete, the user is kept up-to-date regarding the state of their system at all times)
Permanent installation with push-in technology
Classical screw connection technology is still commonly used. If there are extremely many signal lines to be installed however, considerable time can be saved with the quick push-in connection technology (Figure 3 Convenient connection: Conductors can be connected quickly with push-in technology and removed without any special tools). Comparisons with screw connection technology have shown, for example, that the wires can be connected up to 50 percent quicker. Disconnection is also easily possible by pressing the “pusher”. Depending on his preference, the installer can choose between screw and push-in connection technology with the Termitrab complete product range.
Use also in explosion-protected areas
A lightning and surge protection concept is essential because of the higher risk in potentially explosive structural systems, often with far-reaching consequences for persons and the environment. The “intrinsic safety Ex-i” type of protection is useful as a secondary protection measure in this environment. This type of protection limits voltages and currents so that a potentially explosive mixture of ignition energy and temperature is not reached.
For all systems that require high availability, a failure lasting for even a short time is unacceptable. That is why the requirements for surge protection are also more stringent for such systems. The surge protection of the Termitrab complete TTC-Ex product range was designed for such systems. The Ex-i certification of the TTC-Ex components permits the use in field distributors for Ex-zones 1 or 2. Additional approvals attest to the suitability in accordance with Fisco (fieldbus intrinsically safe concept).
Summary
In water and wastewater treatment, there is an increased failure risk in large systems due to surge voltages, often with far-reaching consequences for persons and the environment. A comprehensive and well-planned lightning and surge protection concept is therefore crucial. Using surge protection with telecommunicating status indication ensures quick detection in the control room. Due to the compact design – with only 3.5 mm width for the narrowest components – the space needed for MCR surge protection can be reduced significantly. Use in explosion-protected areas is also trouble-free with the available approvals. Thanks to the comprehensive product range, there is a suitable solution for every application in water and wastewater technology.
Written by:
Jason Phillips, Product Marketing,
Surge Protection Trabtech,
Phoenix Contact Ltd, Milton
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