零相変流器設置上の注意

1. インストールの問題
(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'>完全に密閉された開閉装置の原理は、小動物はもちろんのこと、安全でも防塵でもなく、多くの隠れた危険を残しています。

(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'>変流器、ケーブルの金属シースとアース線は地面から絶縁する必要があり、ケーブルのアース点（ケーブルのアース線とケーブルの金属シールドの間の溶接点）は変圧器の下にあり、アース線は直接接地する必要があります;

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'>変流器。 正しく行動してください。

(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'>変流器の磁気回路が閉じていないため、正常に動作しません。

(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'>変流器の二次コイルを開いてください。

(5) ケーブルの金属シース接地線の接地端は、端子に溶接されておらず、スイッチ キャビネット内の接地用銅棒にも接続されておらず、スイッチ キャビネット本体のボルトにさりげなくラップされています。

2. 正しい設置方法
(1) ゼロシーケンス変流器が選択されていることを確認する必要があります > 変流器の内径がケーブル端子ヘッドの外径よりも大きい;

(2) Try not to dismantle the zero-sequence current transformer'>建設中の変流器。 解体が必要な場合は、作業完了後に元の状態に戻す必要があります。

(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'>変流器は適切に取り扱う必要があります。接地線の相対的な位置は、接地銅バーに取り付ける必要があります。

(4) 電源投入前にゼロシーケンス保護システムを調整して、保護が正常に機能することを確認する必要があります。