Problems should be paid attention to in the design of integrated wiring grounding

1. When the integrated wiring system adopts shielding measures, all shielding layers should be kept continuous, and the relative position between conductors should be ensured. Shielding layer of wiring equipment (FD or BD) end should be grounded, the user (terminal equipment), depending on the specific situation directly, both ends of the grounding: should try to connect to the same grounding body. When there are two different grounding systems in the grounding system, their grounding potential difference should be less than 1VR.M.S (valid value).

2. When the cable from outside the building to enter the interior of the building is susceptible to lightning, power to touch the ground, the power of the inductive potential or ground potential of the impact of external factors such as the need to adopt a protective device.

3. When the line is in any of the following hazardous environments, it should be overvoltage-overcurrent protected:

(1) The dangerous effect caused by lightning strike.

(2) The working voltage exceeds 250V power line to touch the ground;

(3) The power supply fault caused by the increase of ground potential to above 250V;

(4) AC 50HZ induction voltage exceeding 250V.

4. It is advisable to choose gas discharge tube Protector for overvoltage protection of integrated wiring system. Because the ceramic casing of the gas discharge tube protector is sealed with two electrodes, there is a discharge gap and an inert gas is charged. When the potential difference between two electrodes exceeds the 250V AC voltage or the 700V lightning surge voltage, the gas discharge tube begins to appear with an arc, providing a conductive pathway between the conductor and the ground electrode.

5. The overcurrent protection of the integrated wiring system should choose a protector which can be self-reused. As such or such voltage may appear on the cable, if the connecting device provides it with a low resistance path to the ground, it is not sufficient to enable the Overvoltage Protector to act, and the current produced by it may damage the equipment or cause a fire. Example: 20V power line may not be sufficient to enable overvoltage protector discharge, but it is possible to produce large current into the equipment caused by damage, so the use of overvoltage protection must be used at the same time overcurrent protection. It is required to adopt a self complex overcurrent protector, which is mainly for the convenience of maintenance.

In a word, with the continuous development of intelligent building, people will put forward more stringent requirements for its grounding system. For the vast number of engineering and technical personnel, improving the stability and reliability of the integrated wiring grounding system will be a long-term and arduous task.

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