Problems in the installation and operation of the transformer with lightning arrester - News - Global IC Trade Starts Here Free Products

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There are many problems in the installation and operation management of the transformers, and accidents such as burning transformers and bursting arresters occur frequently. For a long time, the arrester has been installed on the upper side of the high-voltage fuse. According to the operation comparison, this installation method is not reasonable. In this regard, the author's discussion is as follows, for peer reference.

1 arrester installation

1.1 There are problems and the lightning arrester is generally installed on the upper side of the high-voltage fuse. According to the regulations: “The height of the base of the variable platform should not be less than 2.5m from the ground.” This requires the entire strip when the arrester is damaged or causes grounding, short-circuit or calibration replacement. The 10kV line is blacked out and is not conducive to loading and unloading. In addition, the grounding lead of the arrester is too long from the ground and does not meet the relevant technical requirements. In view of the above problems, we have changed the installation position of the transformer surge arrester and installed it on the lower side of the high voltage fuse. This does not affect the protection effect and range of the arrester, but also facilitates the normal assembly and disassembly of the arrester, reducing the number of power outages on the entire line. At the same time, when the performance of the arrester is degraded by lightning, the continuous flow of the power frequency will increase, which will inevitably lead to the failure of the arrester itself. The fuse is melted, which will isolate the fault point, reduce the chance of single-phase grounding or short-circuit tripping of the line, and improve the power supply. Reliability rate.
1.2 Installation Precautions The installation point of the arrester should be greater than 0.7m from the fuse to ensure that the safety distance specified in the Electrical Safety Work Regulations is met during maintenance. The lead length of the arrester should be as short as possible and reliable. The wire should use 35~50mm ² black glue line to reduce lead reactance and reduce residual voltage. The arrester distance transformer should be greater than 2m, increase the inductance on the wire, and improve the relative lightning resistance level of the transformer. When the arrester is removed and installed, it cannot be tied with wire or wire, but should be re-installed with special fixtures to prevent creepage. In addition, the down conductor of the arrester must be connected and tied to the cross arm and pole to prevent grounding, short circuit or damage to the transformer when the arrester explodes.

2 Problems in the operation of the arrester

2.1 Due to damage, breakdown, rust and difficult installation, the source of funds and the burden of the cost are difficult. In addition, the responsibility of the village electrician is not strong. There are factors such as the psychology of Zhaoxing, which cannot be installed and replenished in time. Objectively, the installation rate of the arrester is low and installation. Insufficient quantity.
2.2 Due to the large amount of regular calibration work of the arrester, a considerable number of arresters have not been verified for many years, and the arrester that has lost its function is still running on the Internet.
2.3 Due to the unsatisfactory responsibility of construction, installation and maintenance personnel, most of the arresters in operation have looseness, inclination, and abnormalities such as incorrect installation position and lead drop.
2.4 Lightning arrester products have low quality and cannot effectively protect them.
2.5 The grounding leads the strands to break and entangle, and some even use the wire instead of the grounding down conductor, and most of them have the problem of large grounding resistance.

3 How to rectify

3.1 Increase publicity and education to let users understand the necessity and importance of installing lightning arresters.
3.2 Make the electrician master the installation process of the arrester, standardize the construction, and leave no sequelae.
3.3 Strengthen the operation and management work, conduct regular inspections, inspections and verifications. Unqualified lightning arresters cannot be operated online.
3.4 Actively promote the use of zinc oxide arresters.
3.5 Do a careful inspection of the lightning arrester grounding body and transformer grounding body of all distribution transformers in the jurisdiction. The grounding resistance must be thoroughly treated.