【正文】 ruction should pay attention to the appropriate electrode angle, swing, pay attention to the melting of lap joints on both sides.,Earthing and equipotential connection:1 all electrical equipment metal shell, frame, line pipe, cable bridge must have good ground, make it a good grounding for outdoor grounding bar welding length not less than 6times the diameter of round steel, flat steel two surface welding。 is connected by double lapped continuous welding of , weld length not less than 6 times the diameter, good weld appearance。 lightning protection to D. Grounding resistance should be less than10 ohm。 b. Safety grounding, grounding resistance should be less than4 ohm。 welding brush asphalt paint or powder coating。 (3) cable channel equalizing zone。re a lowvoltage electrical equipment power supply voltage only a few tens of volts ), because the digital circuit belongs to positive and negative 5V,12V,24V level, are vulnerable to interference, and once the external abnormal voltage once the series will very possible equipment damage. I just go to work in the factory has a 1000 tons of SACMI press, because other equipment and digital ground causes the electronic facilities burned down last several times, Italy sent technicians ( just graduated from secondary school students ) and replacement equipment, conductor of the in situ dug a pit, buried a piece of ground the brass and the earthing filler, engage in a separate grounding. 3 Lightning proof grounding device for part of a concept (1) Lightning receiving device directly or indirectly accept the lightning rod ( flash ), such as lightning, lightning protection zone ( ), overhead ground wire and arrester. (2) lead: for the lightning current from the lightning arrester is conducted to the grounding conductor. (3) grounding: electrical equipment, tower grounding terminal and a grounding body or the zero line connected with the normally not currentcarrying metal conductor.(4) grounding body ( polar ): buried in the soil and directly touch the earth metal conductor, known as the grounding body. Divided into vertical grounding electrode and level of grounding body.(5): grounding device grounding and grounding. (6): grounding grid by vertical and horizontal grounding body position having discharge and pressure equalizing function work grounding device. (7): grounding resistance of grounding body or natural grounding resistance to the ground of the sum, a grounding device resistance, its value is equal to the grounding device of voltage to the ground and through the grounding body into ground current ratio. At the same time the grounding resistance of grounding device is a constant level indication. 4 The grounding device is easy to corrosion location mainly 4 (1) equipment grounding downlead and connecting screws。 potential 1 introduction In recent years, many domestic and foreign standards do not advocate information equipment using independent grounding device, remend the use of mon earthing system. For example, the 2021 edition of the GB5005794 design code for protection of structures in point out clearly: every building itself should adopt mon earthing system to be the buildings within the various grounding are unified to buildings based on, or outdoor grounding device. When the building was hit by lightning, power system voltage and electrical equipment grounding voltage rises at the same time, keep the equipment working voltage constant, so that the electronic equipment from lightning strikes can work normally. Common earthing system usually use the building foundation grounding electrode, the grounding resistance less than 1 ohm in general, if the equipment grounding resistance requirement is lower, should take the minimum value. The ground that has been incorporated into the lightning protection system of lightning energy drain into the earth, good grounding downlead to effectively reduce the voltage on the back, to avoid the occurrence of. In the past some requirements of electro nic equipment grounding alone, the purpose is to prevent stray current and transient current in power work disturbance of the normal work of equipment. Before 90 time, forces of the munication navigation equipment electronic tube device, using analog munication mode, analog munication on particularly sensitive to interference, interference, so will take power and munications grounding separate way. Now, the lightning protection engineering fields do not advocate a separate ground. In the IEC standards and ITU standards are not advocating a separate ground, American Standard IEEEStd11001992more sharply pointed out: not remended the use of any kind of socalled separate, independent, 2 puter, electronic or other such incorrect ground as equipment grounding conductor of a connection point. Grounding is the most fundamental aspect of the lightning protection system. The ground is not good, all the measures of lightning protection effect can play. Lightning protection grounding is ground munication station Code for construction and acceptance of the basic safety requirements, the grounding of PLC belongs to a lowvoltage electrical equipment of single point grounding mode Low voltage electrical equipment of single point grounding mode can be divided into: tandem type single point grounding, parallel type single point gr