What is the difference between strong current lightning protection and weak current lightning protection?
In the lightning protection design of system integration projects, we often encounter the concepts of strong and weak lightning protection. Sometimes, strong and weak lightning protection devices are also subcontracted to different factories for installation.
So, what is the difference between strong current lightning protection and weak current lightning protection?
Based on the experience of lightning protection design, the following content is elaborated on for lightning protection in China:
1. What does strong lightning protection refer to?
① Strong current lightning protection refers to the lightning protection design for strong current systems. Generally speaking, voltages above DC 36V and AC 24V are called strong current. Installing lightning protection devices and designing lightning protection measures for these strong power supply lines is called strong current lightning protection.
For example, the most common strong current lightning protection design is the three-level lightning protection design of the AC distribution system. The three-phase 380V and single-phase 220V of the AC system belong to the strong current range.
The selection of lightning protection devices for high-voltage systems can be based on system voltage and distribution system, such as selecting a 4P three-phase power supply lightning protection device for AC 380V TN-S systems and a 1P or 2P DC surge protection device for DC 220V.
2. What is weak current lightning protection?
Weak current lightning protection refers to the lightning protection design of various signal communication transmission lines for 24VDC and below, such as lightning protection for network cable transmission, RS485 line, telephone line, video monitoring, fire alarm system, etc., all of which belong to the category of weak current lightning protection.
Weak current communication equipment, due to its high integration and numerous precision components, is prone to damage when surges invade the system. Therefore, current outdoor weak current systems are designed for lightning protection.
For example, in outdoor monitoring systems, corresponding lightning arresters will be installed on the video and power lines of the cameras.
Various outdoor monitoring instruments will also be equipped with corresponding on-site instrument weak current signal surge protectors.
3. What is the difference between strong current lightning protection and weak current lightning protection
① Different application voltages
From the above introduction, we can know that the main difference between strong current lightning protection and weak current lightning protection is the applied voltage. Strong current lightning protection design is mainly aimed at AC distribution systems, while weak current lightning protection is mainly aimed at signal communication systems.
② The selected lightning arrester is different
Strong current lightning protection devices and weak current lightning protection devices are completely different. The commonly used lightning protection device for strong current lightning protection is the power supply lightning protection module, while the commonly used lightning protection device for weak current lightning protection is the signal lightning protection device. According to the different transmission rates and interfaces of the signal line, different weak current signal lightning protection devices are matched.
③ Different qualifications of construction personnel
The construction personnel of the strong current lightning protection system must have an electrician certificate, and be cautious of the risk of electric shock during installation. For weak current lightning protection, as it mainly involves signal line construction, only signal line lightning protection construction does not require an electrician certificate.
In actual lightning protection design, strong and weak current lightning protection are often integrated designs, because in intelligent systems, strong and weak currents themselves are in a state of mutual benefit, and their corresponding lightning protection design is also the same.
