1. The integrated wiring system using shielding measures, all of the shield should maintain continuity, and due care must be taken to ensure that the relative position between the same wire. Shield of wiring devices (FD or BD) connected to the user (terminal) depending on the specific circumstances, directly at the ends of the earth: try to connect to the same grounding system. When the grounding system exists in the two, different grounding system, the ground potential difference should be not greater than 1 vr. Margaret spellings (RMS).
2. When the cable from the outside to enter the building internal vulnerable to lightning strike, power, power induction electric potential or the impact of external factors such as ground potential rise, must adopt the protector.
3. When the line is in any of the following a dangerous environment, dealing with the over-voltage over-current protection:
The risk of (1) caused by lightning.
(2) working voltage exceeds 250 v power supply line to touch the ground;
(3) the ground potential rise to more than 250 v power failure caused by;
(4) ac 50 hz induced voltage exceeds 250 v. Beijing integrated wiring
4. The integrated wiring system of over voltage protection appropriate chooses the gas discharge tube protector. Because of the gas discharge tube protector ceramic shell sealing has two electrodes, which has a discharge gap, and filled with inert gas. When the potential difference between the two electrodes are more than 250 v or 250 v ac voltage lightning surge voltage, the gas discharge tube arc, began to appear between conductor and earth electrode provides a conductive path.
Over-current protection of the integrated wiring system, appropriate chooses to self restoring protector. Due to voltage cables may appear this or that, if the connection device with low resistance pathways to the ground, is enough to reduce overvoltage protector action, and the resulting current may damage the equipment or cause fire. Example: 20 v power line may not be enough to make the over-voltage protector discharge, but may produce large current into the equipment internal damage, so in the overvoltage protection over-current protection must be used at the same time. Over-current protector can require the use of the compound, mainly for the convenience of maintenance.
In a word, with the continuous development of intelligent building, people will certainly puts forward stricter requirements to the grounding system. For the general engineering and technical personnel, improve the stability and reliability of integrated wiring grounding system will be a long-term and arduous task. I see the road, we need to search up and down.