Electrical equipment grounding device operation and maintenance

During the operation of the grounding device, the grounding wire and grounding body are damaged or broken due to external force damage or corrosion, and the grounding resistance also changes with soil change. Therefore, the grounding device must be inspected and tested regularly.

1. Regularly check the grounding device of the 1 change (distribution) station and check it once a year;

2 According to the specific conditions of the workshop or building, the operation of the grounding line is generally checked once or twice a year;

3 Grounding devices of various lightning protection devices are checked every year before the thunderstorm season.

4 For the grounding device with corrosive soil, the grounding body under the ground shall be inspected once every 3 to 5 years according to the operation conditions;

5 The grounding wire of hand-held, mobile electrical equipment should be inspected before each use;

6 The grounding resistance of the grounding device is usually measured once every 1 to 3 years.

2. Check item 1 Check that the contact points of the grounding device are in good contact with no damage, breakage or corrosion.

2 For the soil zone containing chemical components such as heavy acid, alkali and salt (generally chemical production enterprises, pharmaceutical production enterprises and some food industry enterprises), the corrosion degree of the grounding body above 500 mm above the ground should be investigated.

3 Measure the grounding resistance of the grounding device when the soil resistivity is maximum (usually before the rainy season), and analyze and compare the measurement results.

4 After the electrical equipment is overhauled, check the connection of the grounding cable. Is it firm and reliable?

5 Check whether the connection between the electrical equipment and the grounding wire, the connection between the grounding wire and the grounding wire, and the connection between the grounding wire and the grounding wire are in good condition.

The design of intelligent building grounding system 1, lightning protection grounding system grounding body generally use intelligent building pile foundation, the top of the pile base reinforcement steel together by the bearing platform; lightning protection grounding system down the general use of pillar steel reinforcement; The device uses a combination of a lightning conductor and a lightning rod. Intelligent buildings are 30 meters or more in length. Every three layers are connected by a ring beam reinforcement and column bars to form a pressure equalizing ring; grounding resistance requirements are less than 1 ohm.

2. The work grounding system line is the N line in the power system.

3. Protective grounding system, set up the equal equipotential copper bar in the appropriate place of the substation, and draw the strong PE trunk from the equipotential copper bar. Each layer is set with an auxiliary equipotential copper bar in the appropriate place. Ground wire to the device housing and metal pipe.

4, DC grounding system. The reference potential of the DC grounding system is derived from the total equipotential copper bar, which uses 35 copper insulated wire. The protection of the steel pipe is directly led to the equipment and used for DC grounding.

5, power grounding. The insulated copper core wire with the same cross-section as the phase conductor is taken from the floor Distribution box together with the phase conductor. In the TN-S system, it is the neutral wire N.

6, shield grounding and anti-static grounding, from the total equipotential copper row leads PE weak mains, each layer in the appropriate location of weak auxiliary equipotential copper row, electronic equipment shell, metal pipe shielding and anti-static grounding are caused Weakly assisted equipotential copper bar.