Within a process plant, upwards of 1,000 mechanical switches may be used in order to govern hard alarms, fans, emergency shutdowns, and more. While these mechanical switches have served their purpose well since their implementation, they can often take up a great amount of space, may be nearing the end of their service lives, and present various downsides in their operation. Additionally, such mechanical switches can also be replaced with more efficient and productive alternatives that continue to be developed with high capabilities. In this blog, we will discuss the main alternatives to mechanical switches, offering considerations that should be made to decide whether it is time to make the switch.
When looking to replace a switch for process and safety operations, electromechanical switches can be a highly economical choice due to their costs. Despite this, electromechanical switches are blind, meaning that finding issues can be difficult due to the amount of moving parts present in the system. To test such components, switches also need to be removed and tested separately, causing the system to be unprotected during the inspection. With a digital switch, on the other hand, operational visibility is much greater, and personnel can refer to LCD screens that typically provide various diagnostics and health monitoring. Such switches can greatly increase the safety and reliability of the system as a whole, as digital switches can often identify almost all potential failures that arise before they become a bigger problem.
Beyond identifying and resolving issues, electromechanical switches also require precise adjustments to meet specific needs, and deadband adjustments may not be possible for such components. Additionally, temperature and ambient changes within the system during operation cause these adjustments to drift, resulting in inaccuracies that can have an affect on processes. As mechanical switches may be dated in a given plant, acquiring the proper documentation required to make such adjustments can also prove difficult. With digital switches, on the other hand, adjustments can be made extremely quickly, and LCD screens and electronics allow for programming of the switches to be set instantaneously. Electronic switches also allow for full adjustment of deadband and set point, thus permitting accurate control for a number of demanding applications that mechanical switches cannot assist in. With no moving parts, digital switches also present high reliability, and there is less need for redundant switches to be present in the case of a failure.
With their operational visibility and adjustability, digital switches prove to be a very safe alternative to mechanical switches, decreasing the chance of a failure for industrial processing plants. Safety instrumented systems, or SISs, are often utilized by facilities for the safety of processing, and they can be used to detect potential issues that can pose danger in order to activate alarms and valve systems. For the SISs to function properly, they require fault tolerant switches, which electromechanical switches are unable to provide. Because of this, digital switches, transmitters, logic solvers, and other components are utilized for safety.
One of the highest causes of failure for electromechanical switches is vibration, and such switches are typically placed in harsh environments where there are high levels of vibration, heat, pressure, and mechanical shock. With shock and vibration, electromechanical switches may have their plunger positions altered, possibly leading to false trips. As digital switches do not require any moving parts, they are much less prone to the conditions that may cause failure for electromechanical switches. Additionally, the fitting of plant wiring, increased response times, and high reliability make digital switches very beneficial for the modernization of industrial plants for safety, efficiency, and more.
When you are searching for electromechanical and digital switches for your operations, let the experts at NSN Fulfillment help you secure everything that you need with ease. We carry a number of premium switches on our website, including EAO International manufacturer parts and Schurter Inc manufacturer parts. Peruse our robust catalogues to find top requested part numbers such as 0014-0645, 0041.8841.3307, 01-030.005, 023-021-040, 05001-03N, and more, all complete with competitive pricing and rapid lead-times.
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