Field instruments that require or do not require the installation of surge protectors (SPD)
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This post was last edited by zhoudingshengs on 2023-11-21 at 13:39. Field instruments that require or do not require surge protectors (SPDs): According to SH/T 3164-2021 \"Code for Lightning Protection Design of Petrochemical Instrument Systems\", surge protectors should be installed for instruments on the control room side when the horizontal straight-distance between the signal cables and the ground is greater than 100m or the vertical distance is greater than 10m； Electrophoretic protectors should be installed on the instruments on the control room side of the above-ground tank farm instruments. Meeting the criteria: When the horizontal straight-line distance at which the signal cable is laid above the ground is greater than 100 m, or the vertical distance is greater than 10 m, conditions are met for installing surge protectors. Surge protectors should be installed on the instruments in the control room, or on the following field instruments in the above-ground tank area: 1. Electrical and electronic measuring instruments that convert signals into electrical signals, such as transmitters. 2. Gas detectors, analyzers. 3. Electric and electrical signal actuators such as electrical converters, electrical valve positioners, solenoid valves, and electric actuators. 4. Thermal resistor. 5. Electronic switch. 6. Relay coil. 7. Network and communication devices fixed in place. 8. Other instruments that are sensitive to lightning surges or cannot withstand them. Meters that do not require a surge protector: 1. Thermocouples. 2. Mechanical contact switches, buttons. 3. Instruments that are not electric or unrelated to electrical signals. 4. Other instruments capable of withstanding lightning surges. In addition to installing surge protectors, the surge protection for field instruments should also be achieved through shielding and grounding to prevent them from becoming lightning receptors. When the installation location of on-site instruments may cause them to function as lightning receptors and they cannot be moved, the instruments should be installed in instrument protection boxes made of fully enclosed steel plates.
The \"Code for Lightning Protection Design of Petrochemical Instrumentation Systems\" SH/T 3164-2021 provides specific guidelines on whether surge protectors (SPD) are required to be installed on field instruments. According to the specifications, surge protectors need to be installed in situations where: the horizontal distance along which the signal cable runs above the ground exceeds 100 meters, or the vertical distance exceeds 10 meters; in such cases, surge protectors must be installed on the instruments located in the control room. - Surge protectors should also be installed on the instruments in the above-ground tank farm area on the control room side. Types of field instruments that require the installation of surge protectors include: 1. Electric and electronic measuring instruments such as transmitters, which convert non-electrical signals into electrical signals. 2. Gas detectors, analyzers. 3. Electric and electrical signal actuators such as electrical converters, electrical valve positioners, solenoid valves, and electric actuators. 4. Thermal resistor. 5. Electronic switch. 6. Relay coil. 7. Fixed network and communication equipment. 8. Other instruments that are sensitive to lightning surges or cannot withstand their effects. Instrument types that do not require a surge protector include: 1. Thermocouples. 2. Mechanical contact switches, buttons. 3. Non-electric or signal-independent instruments. 4. Other instruments capable of withstanding the effects of lightning surges. In addition to installing surge protectors on the equipment, lightning protection measures should also include proper shielding and grounding to prevent the field instruments from becoming lightning strike points. If the installation location of the field instrument may expose it to direct lightning strikes and the location cannot be changed, the instrument should be installed in a protective box made of fully enclosed steel plates. This allows for better protection of the instruments, preventing them from being damaged by lightning. .
OP, please don’t use artificial intelligence to answer your own questions……
Tips for selecting parameters of instrument surge protectors: 1. Choose appropriate parameters; values that are either too high or too low are not suitable. 2. The parameters of surge protectors are data measured under laboratory conditions in accordance with the specifications of testing standards, and they indicate and verify that the protectors possess characteristics similar to those under actual lightning strikes. 3. Surge protectors should be tested for their parameters and performance in batches, and they must come with a certificate of conformity. 4. The manufacturer of surge protectors shall have equipment for testing simulated surges using standard test waveforms, and the testing shall be carried out by the manufacturer in accordance with GB/T 18802.21 or the manufacturer’s own standards. 5. Units or institutions that do not have simulation surge testing and inspection equipment with lightning standard test waveforms shall not conduct inspections. 6. The surge protectors for instruments should be maintenance-free and capable of withstanding multiple lightning surge impacts without being damaged. 7. Surge protectors with monitoring functions can be used, along with a corresponding centralized intelligent lightning protection monitoring system. 8. Select the proper surge protector for the protection of signal and data systems (such as fieldbuses, 4–20 mA signals, telephony, and network communications), ensuring that it does not affect or alter the characteristics and reliability of the application systems. 9. Intrinsic safety certification of surge protectors used in intrinsically safe systems for explosive hazard environments.