The function and wiring of surge protection devices
Today, we will introduce the concept, function, installation and wiring of surge protectors to everyone.
Surge protector is an electronic device that provides safety protection for various electronic devices, instruments, and communication lines. It is also known as lightning arrester, which protects against indirect lightning, direct lightning impact, or other transient overvoltage surges.
Surge protectors are generally connected in parallel with the protected equipment. When there is a sudden surge current or voltage in the electrical circuit or communication line due to lightning interference, the surge protector can conduct and divert current in a very short time, which can have the effect of leakage and voltage limiting, preventing excessive current and voltage from causing damage to the equipment. Overall, its main function is to protect electronic devices from damage caused by surges.
The lightning surge protection of the distribution system has multiple levels of protection, generally including the first level protection (main distribution cabinet), the second level protection (distribution cabinet), the third level protection (equipment location), etc. (the following introduces surge protection at equipment location). In addition, different occasions have different electricity requirements, which have led to many power supply systems, including TT systems, TN-S systems, TN-C systems, etc. Surge protectors also have different models to cope with these different power supply systems.
Generally speaking, TT systems require the use of 1P+N or 3P+N surge protectors (with gas discharge tubes as the N-pole component), TN-C systems can choose 1P and 3P surge protectors, while TN-S systems can choose 1P+N, 3P+N, or 2P and 4P surge protectors. What we usually see is the usage of TN-S systems and single-phase systems.
So how are surge protectors wired and installed?
Firstly, we need to identify some letters on the power lightning arrester, such as "L", "N", and "PE". These are the letters that can be seen on this surge protector, representing the live wire, neutral wire, and ground wire, respectively.
In general distribution boxes, a backup protection device needs to be connected in series to the upper end of the surge protector, but the Delixi DZ47vY-III Class III surge protector has built-in backup protection. When wiring, connect the power lines from the main switch to the "L" and "N" wiring holes of the lightning arrester. Lead out the grounding wire from the "PE" wiring hole and connect it to the ground wire bar. The protected electrical equipment is connected in parallel with the surge protector,
Under normal circumstances, it is necessary to install a surge specific backup protection device in front of the surge protector. So what is a surge backup protection device and what is its function?
The surge backup protection device can selectively disconnect the passing power frequency current and lightning current. When lightning current passes through the surge protection device, the lightning current flows through the discharge circuit without passing through the trip coil. The backup protection device will not trip incorrectly, ensuring that the lightning protection of electrical equipment is always in an effective state.
When the surge protector fails and there is a power frequency overcurrent flowing through it, the current flows through the trip coil circuit. At this time, the trip coil acts, disconnecting the circuit and disconnecting the surge protector from the parallel line, so that the surge protector will not cause overheating and accidents such as fire and explosion, while ensuring continuous power supply.
