Whitepaper Improvements in Marshalling for the Processing Industry
Roger Highton, MTL Product Line Manager at Eaton, reviews the challenges faced by modern processing plants and how a pioneering approach to marshalling can deliver big benefits.
As the processing industry becomes more automated, the increased use of fieldbuses and smart devices makes a distributed control system (DCS) essential in large and complex operations. Marshalling is the critical process bringing order to control signals and can be defined by the grouping of inputs and outputs (I/O). It enables diverse operating systems to interact, and it encompasses a wide range of requirements: including intrinsic safety (IS) isolation, signal conditioning, relay interfaces, surge protection and cable terminations, often including loop disconnects.
However, marshalling is also a neglected area of system design that has historically lacked an overall vision for future development. This is a challenge that Eaton, as a leader in reliability, efficiency and safety of electrical products, has been keen to address.
It can be a challenge for processing plants to know what their exact marshalling requirements may be in a few years’ time because a facility grows, projects evolve and customer priorities change. Therefore, marshalling system flexibility is paramount to prevent delays from changes (and associated cost increases) in project specification.
Traditionally there may be up to five separate cabinets for different marshalling functions, with complex wiring between the marshalling components: up to eight interconnections per channel. This creates a complex wiring structure, and is a major source of faults and downtime.
Another major source of complexity is multiple components from multiple suppliers. A traditional marshalling solution with IS typically involves 20 different component types. During later design stages the component type often needs to be amended, which results in changes to the Bill of Materials that are long and complex. Additionally, late changes make it difficult for end users to maintain the marshalling system and control lifetime costs.
Space requirements are also a key challenge—particularly in oil & gas processing—and marshalling systems can become increasingly unwieldy as further cabinets are added in response to post-installation changes.
Clearly, it is time for a new solution that facilitates a standard design for all marshalling requirements, that is compact and space-saving, while at the same time is simple to install and maintain. Furthermore, any new marshalling solution should be flexible, easy to reconfigure and have minimal impact on project and whole life cost.
A New Approach
Eaton has applied its combination of industry knowledge and technical expertise to develop a new marshalling solution that offers the simplification and standardisation that customers are seeking, with no compromise on functionality. Smart Universal Marshalling (SUM) is a modular approach that enables the five key marshalling requirements to be achieved using a single cabinet design. Eaton calls its solution MTL Sum5. Let’s take a closer look at some of the benefits:
● All the marshalling functions are in one unit, so there is no longer any requirement for complex, hard-wired interconnections - eliminating the risk, downtime and associated costs that arise from wiring faults.
● The configurable design accommodates late changes, reducing risk during project execution. It also ensures that the system is adaptable over time, without major rewiring or the need for cumbersome ‘bolt-on’ equipment.
● Smart Universal Marshalling typically reduces the number of marshalling components by 65 % compared to a standard solution. For example, on a project with 4,500 I/O small changes in the number of each I/O type results in the Bill of Materials for the traditional solution required 4,651 changes. The Bill of Materials for the same project using MTL Sum5 would require only 115 changes.
● The modular ‘plug and play’ approach makes maintenance simpler. Fewer component types mean fewer spare parts need to be held in stock. With MTL Sum5, configuration information is held in the terminal, so a module can be changed out without the need for reprogramming.
● The modular design approach eliminates some components altogether and makes others more compact, so there is typically a 30-50 % saving in the number of marshalling cabinets required. This in turn means there is potential to reduce the overall size of control rooms - freeing more room for production.
Smart Universal Marshalling addresses customer concerns regarding the costs and complexities associated with traditional marshalling systems. It significantly reduces the number of components required and totally eliminates the need for complex wiring. This in turn delivers advantages that include a reduced Bill of Materials, simplified installation and maintenance, and the ability to adapt rapidly to change. In short, it makes marshalling fit for purpose in an automated, connected world.
For more information, download Eaton’s free whitepaper Smart universal marshalling: its evolution and benefits here