What are the basic requirements for outdoor installation of distribution transformer
Writer： Hengfeng you electric Time：2023-04-07 views：times
What are the basic requirements for outdoor installation of distribution transformers?
There are several types of transformer measurements, I don't know what your purpose of measurement is. There are usually measurements of unpowered and powered states. In the no-power state, first measure whether the conduction state of the main coil and auxiliary coil (input and output) is clear.
1. General requirements for pole-frame transformer installations
(1) The pole-type transformer should be installed close to the load center to reduce the line power loss and line voltage drop of the low-voltage power supply line. Under normal circumstances, the substation is located near the unit with large power consumption, and the voltage drop of the farthest electrical equipment should be within the allowable range. The installation location should be easy for maintenance, and avoid installing it in places where the installation poles such as corner poles and branch poles are messy.
(2) The distance between the transformer shape and the combustible building should be greater than 5m; the distance from the refractory building should not be less than 3m.
(3) The distance between the transformer platform and the ground should not be less than 2.5m; the distance between the lower edge of the low-voltage distribution box and the ground should not be less than 1m.
(4) The height of all exposed charged bodies on the transformer platform should be greater than 3.5m from the ground.
(5) When the high and low voltage lines are erected on the same pole, the low voltage line should be located below the high voltage line, and the distance between the high and low voltage cross-arms should not be less than 1.20m.
(6) Warning signs should be installed at a clear position 2.5-3.0m away from the ground.
(7) In areas where the air contains flammable and explosive gases or dust that has a destructive effect on insulation, it is not suitable to install pole-type transformers, and indoor substations should be used.
2. General requirements for floor-standing transformer installations
(1) When the capacity of the outdoor transformer is 320kVA and below, the method of replacing the platform on the column can be adopted; when the capacity exceeds 320kVA, the method of replacing the station on the ground can be adopted.
(2) Floor-type transformers should have a solid foundation. The ground height should not be less than 0.3m. Generally 0.3~0.5m. During the safety period, a fence or gate with a height of not less than 1.8m should be set around the transformer. The clear distance between the transformer shell and the fence or gate should not be less than 0.8m, and the clear distance from the gate should not be less than 2m.
(3) The down-conducting pole of the transformer should be inside the fence. After the disconnector or fuse is powered off, the height of the live part from the ground should not be less than 4m, and should not be less than 3.5m when there are obstacles. The door to the changing platform should be locked and a warning sign "STOP, DANGER OF HIGH VOLTAGE!" should be hung on the door. Access to the fence is only possible after the power has been cut off.
(4) The height of the cross arm of the drop-out fuse from the ground should not be less than 4.5m.
(5) The installation of the transformer on the column should be stable and firm. The waist rail is surrounded by a cold-lapped steel wire (usually called iron wire) with a diameter of 4mm for more than four turns. The steel wire for cold lap joint shall not have joints, and the surrounding shall be tightened. 2m. The distance between the waist and the live part is not less than 0.2 million.
(6) The inclination angle of the transformer high voltage drop fuse device is 25°~30°, and the interval between phases should not be less than 0.7m.
(7) The installation of the fuse on the low-voltage side of the transformer shall meet the following conditions: When there is a blocking switch on the low-voltage side, the fuse shall be installed between the blocking switch and the low-voltage insulator; when there is no blocking switch on the low-voltage side, the fuse shall be installed in the The outside of the low-voltage insulator, and bridge the insulated wires at both ends of the fuse block with insulated wires.
