Serviceline Industrial Sensors
Serviceline Explosion Protection

Reliable Surge Protection for Petrochemical Companies

Power Surge—The No. 1 Underestimated Cause of Damage

The Application

Electrical discharges take the form of lightning about 1.4 billion times a year worldwide. This can result in dangerously high differences in potential at up to two kilometers from the actual point of impact. It is therefore no surprise that overvoltage caused by lightning strikes is one of the most common causes of electronic damage.

Lightning strikes are particularly common in Thailand because of the conditions of the climate, therefore plants based in Thailand need especially reliable surge protection. Surge protection is particularly important for petrochemical plants, because incidents of overvoltage in this environment can have especially devastating consequences.

A single lightning strike can damage or destroy expensive machines and plants and ultimately lead to the failure of entire automation systems. Above all, there is always the danger that people will be harmed. Completely reliable surge protection is therefore critical to the safety of petrochemical plants.

The Goal

One of the largest integrated petrochemical companies in Thailand had already installed surge protection in all existing plants. However, since the company was still experiencing repeated failures due to overvoltage, it was decided to completely replace these devices and install reliable protection when a chemical plant was modernized. The enormous size of the plant posed a particular challenge. The surge protection elements in all 10,000 signal circuits in the plant had to be replaced.

The Solution

The customer set the strictest requirements for the new solution. The devices had to meet the IEC standard. In addition, the customer requested intrinsically safe modules with IECEx and SIL certification, which can be plugged in during ongoing operation without plant down time. It was expected that the modules would include a failure indicator with a remote alarm feature.

That is why they chose M-LB-5000, the new generation of surge protection modules. The devices are equipped with all of the required global certifications. The modular structure of the surge protection system allows modules to be replaced during operation, as stipulated by the customer. If the protection module is plugged in at a 180-degree angle, the signal circuit is opened. In addition, the intelligent diagnostics, with status indicator and alarm feature, ensure a high level of transparency and ease of use. As the customer requested, this solution includes on-site support in Thailand at all times.

Technical Features

  • Extremely compact housing design (6.2 mm width)
  • Intrinsically safe with IECEx and SIL certification
  • Wear monitoring with early warning stage
  • Integration of diagnostic data into the control level via Power Rail without additional wiring
  • Traffic-light display for immediate readability
  • Loop disconnect function

The Benefits

The M-LB-5000 surge protection module offers an intuitive, easy-to-read traffic light indicator, which can be integrated into the control level as a status message. This allows maintenance personnel to check the effectiveness of the surge protection equipment at any time, without additional test equipment and without entering the plant.

The surge protection system consists of a base module and a removable protection module, which can be easily replaced during ongoing operation. If the module is removed and then plugged in at an angle of 180 degrees, the signal circuit will be broken via the integrated isolating function. This “loop disconnect function” allows simplified commissioning and troubleshooting. The M-LB-5000 modules can replace terminal blocks in the cross connect level with no additional space requirement due to their small, 6.2 mm installation width. The modules have user-friendly mechanics and are particularly easy to install with no additional wiring requirements.

At a Glance

  • Lightning strikes can damage expensive machines and plants and ultimately lead to the failure of entire automation systems
  • Reliable surge protection is essential
  • The intelligent surge protection M-LB-5000 allows tool-free module replacement during operation
  • The diagnostics, which supply status messages to the control level, ensure safety and flexibility


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