The role of ground potential counterattack protector

When the power distribution system is struck by lightning and when switching on or off inductive loads or large loads, it often produces high operating overvoltages, also called surge voltages. Surges on the lines can cause damage to the circuits and components of electronic equipment. Failure, burn out equipment components.

Our power supply line and equipment grounding line are the two ports where the equipment is most likely to introduce lightning surge pulses. It is a common practice that we care about installing surge protectors on equipment access lines. When our grounding is not good, because the ground resistance is too large, the residual voltage of the discharged lightning is too high, and the high ground potential counterattack enters the equipment through the grounding wire, causing damage to the signal network equipment.

IF: IE=10kA (10/350μs), RB=20Ω

Uf=IE×RB=10*20=200kV;

The 200kV residual voltage enters the weak current and signal protection ground of the communication network through the shared grounding system, causing communication interruption and other faults.

Therefore, we take advantage of the high impedance characteristics of the ground flashback protection device against lightning surge pulses to force the lightning surge pulse to be discharged into the grounding device through the bleeder unit. At the same time, the ground flashback protection device prevents the high ground potential counterattack from entering the signal network equipment, effectively preventing energy Through the low voltage working ground and signal protection ground, the low voltage and weak current signal lines can be entered, so that the grounding resistance value of the protected system to the ground can be relaxed, and the protection requirements can be met by simple grounding (such as the building foundation steel bar as a grounding device) .

By installing the ground flashback spd protection device, the ground potential counter-strike shunt can be reduced to less than 5% of the original counter-strike current, effectively solving the harm caused by the lightning surge pulse when the grounding state is poor. At the same time, it can be used with surge protectors of lightning protection products to effectively reduce the lightning residual voltage and residuals of the protected equipment, thereby protecting the equipment.

IF: IE=10kA (10/350μs) RB=40Ω IR%=3%

IR=10*3%=300A

Uf=IE×RB=10*40*3%=12kV;

The installation of lightning counterattack protection device can reduce the amplitude of counterattack voltage and current to 3-5% of the original value, which greatly protects the line equipment.

Remarks: Simply grounding is required, and grounding is also required. Completely ungrounded neither meets the requirements of various electrical codes, nor can it meet the conditions of use of this product. Will not play a protective effect.