2 questions about surge protectors

1. Instrument valves and transmitters require surge protectors in the following main situations: – Instruments and transmitters installed outdoors or in areas prone to lightning strikes are exposed to the natural environment, making them susceptible to surge currents generated by lightning strikes; therefore, surge protectors are necessary for them. - It should be installed in areas with frequent lightning activity, such as those with long thunderstorm seasons and high incidences of lightning. Since lightning is common in these areas, it causes significant surge currents that can damage instruments and transmitters; therefore, surge protectors are necessary. - Instruments and transmitters that require accurate and reliable data collection need to ensure that the signals collected are not disrupted by surge currents; therefore, surge protectors are also necessary. 2. Many brands of transmitters available on the market today already come equipped with surge protectors. Some common brands include ABB, Emerson, Siemens, Honeywell, Yokogawa, etc. These brands usually specify in their product specifications or manuals whether they have a built-in surge protector, allowing users to choose the appropriate brand and model based on their needs. .

Refer to section 7.4 Surge Protectors in SHT 3164-2021. For the settings of built-in surge protectors, consult the instrument manufacturer directly; note that the requirements specified in clause 7.3 above must be met.

The need to equip control valves and transmitters with surge protectors is mainly related to factors such as the frequency of lightning activity, the condition of the power system, and the importance of the equipment. Generally, in situations where there is frequent lightning activity, the insulation level of the power system is low, or the equipment is of high importance, surge protectors are needed to safeguard control valves and transmitters from damage caused by lightning and other surges. Specific requirements can be found by referring to relevant standards and specifications, such as GB 50057-2010 \"Code for Design of Lightning Protection of Buildings\" and GB 50343-2012 \"Technical Code for Lightning Protection of Electronic Information Systems in Buildings\", etc. In these standards and specifications, it is possible to determine whether surge protectors are necessary based on factors such as the lightning protection zone in which the equipment is located, the importance of the equipment, and the frequency of lightning activities. Transmitters are required to have built-in surge protectors, and some brands indeed offer this feature. For example, transmitters from brands such as Honeywell, Johnson Control, and Emerson are equipped with surge protectors that can effectively prevent damage to the equipment caused by lightning and other electrical surges. Other brands such as Siemens, Yokogawa, Fuji, etc., also offer corresponding products. The specific brand of transmitter to choose requires comprehensive consideration based on actual needs and application scenarios.