Langkah berjaga-jaga untuk pemasangan pengubah arus jujukan sifar

1. Masalah dalam pemasangan
(1) Zero-sequence current transformer'>The current transformer should be installed on the bottom plate of the switch cabinet, and should be fixed by a reliable bracket. However, some manufacturers or construction units install the zero-sequence current transformer'>current transformer on the bracket under the bottom plate of the switch cabinet, and even bind the zero-sequence current transformer'>pengubah arus pada kabel, yang melanggar Prinsip suis tertutup sepenuhnya tidak selamat dan tidak kalis debu, apatah lagi haiwan kecil, meninggalkan banyak bahaya tersembunyi.

(2) After the cable terminal passes through the external zero-sequence current transformer'>current transformer, the relative position of the cable's metal shielded grounding wire and the external zero-sequence current transformer'>current transformer is incorrect. According to the "Beijing Electrical Engineering Installation Regulations", the metal sheath at the terminal of the three-core power cable must be well grounded; the copper shield of each phase of the plastic cable and the steel armor should be tin-welded with the ground wire (oil-impregnated paper insulated cable lead-clad and armored) The ground wire should be welded), when the cable passes through the zero-sequence current transformer'>pengubah semasa, sarung logam kabel dan wayar tanah harus dilindungi dari tanah, dan titik tanah kabel (titik kimpalan antara wayar tanah kabel dan perisai logam kabel) berada di bawah pengubah, wayar tanah harus dibumikan terus ;

When the grounding point is above the transformer, the grounding wire should pass through the transformer for grounding. The grounding wire must be connected to the special grounding copper bar in the switch cabinet. The grounding wire must be copper stranded wire or tinned copper braided wire. The cross section of the grounding wire must be Meet the requirements of the regulations. During the inspection, it was found that some cable grounding wires should pass through the zero-sequence current transformer'>current transformer, and some cable grounding wires should not pass through the zero-sequence current transformer'>pengubahsuai arus elektrik. Bertindak betul.

(3) Due to the relatively large cable terminal, the magnetic circuit of the current transformer'>current transformer is not closed. At present, the commonly used 10kV power cables are three-core XLPE cables. >The current transformer cannot be put on, and the zero-sequence current transformer is disassembled during the construction'>The current transformer interface, the cable is put on, but the interface is forgotten to be restored; some are restored, but the interface is not restored strictly; some terminals The separation of the first three cores is thicker than the zero-sequence current transformer'>current transformer's inner diameter and just stuck in the middle of the zero-sequence current transformer'>current transformer so that the zero-sequence current transformer'>current transformer interface cannot be restored to close, resulting in Zero-sequence current transformer'>Litar magnet pengubah semasa tidak ditutup dan tidak boleh berfungsi dengan normal.

(4) The zero-sequence current transformer'>current transformer's secondary connection was opened during the cable construction, and it was not restored in time after the work was completed, causing the current transformer'>gegelung sekunder pengubah semasa untuk dibuka.

(5) Hujung pembumian dawai pembumian sarung logam kabel tidak dikimpal pada terminal, atau disambungkan ke bar kuprum pembumian dalam kabinet suis, tetapi dilekatkan secara santai pada bolt badan kabinet suis.

2. Kaedah pemasangan yang betul
(1) Perlu dipastikan bahawa pengubah arus jujukan sifar dipilih > diameter dalam pengubah arus lebih besar daripada diameter luar kepala terminal kabel;

(2) Try not to dismantle the zero-sequence current transformer'>pengubah arus semasa pembinaan. Sekiranya ia mesti dibongkar, ia mesti dipulihkan kepada keadaan asalnya selepas kerja selesai;

(3) The grounding wire must be copper stranded wire or tinned copper braided wire, the cross-section of the grounding wire should not be less than 25mm2, the grounding end should be welded with a terminal, and the grounding wire and the zero-sequence current transformer'>pengubah semasa hendaklah dikendalikan dengan betul Kedudukan relatif wayar pembumian mesti dipasang pada bar kuprum pembumian;

(4) Sistem perlindungan jujukan sifar hendaklah dilaraskan sebelum dihidupkan untuk memastikan perlindungan berfungsi dengan normal.