Prekosyon pou enstalasyon transfòmatè aktyèl sekans zewo

1. Pwoblèm nan enstalasyon
(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'>aktyèl transfòmatè sou kab la, ki vyole prensip la nan switchgear konplètman fèmen se ni san danje ni pousyè-prèv, se pou kont li ti bèt, kite anpil danje kache.

(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'>transfòmatè aktyèl la, djenn metal kab la ak fil tè a ta dwe izole soti nan tè a, ak pwen an tè kab (pwen an soude ant fil la tè kab ak plak pwotèj metal la kab) se anba a transfòmatè, fil tè a ta dwe dirèkteman tè. ;

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'>transfòmatè aktyèl la. Aji dwat.

(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'>Sikwi mayetik transfòmatè aktyèl la pa fèmen epi li pa ka travay nòmalman.

(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'>bobin segondè transfòmatè aktyèl la louvri.

(5) Fen a tè nan fil metal djenn kab la tè a pa soude nan tèminal la, ni konekte ak ba an kwiv la tè nan kabinè a switch, men li dekontrakte lapped sou boulon yo nan kò a kabinè switch.

2. Metòd enstalasyon kòrèk
(1) Li ta dwe asire ke transfòmatè aktyèl la zewo-sekans chwazi > dyamèt enteryè transfòmatè aktyèl la pi gwo pase dyamèt ekstèn tèt tèminal kab la;

(2) Try not to dismantle the zero-sequence current transformer'>transfòmatè aktyèl pandan konstriksyon. Si li dwe demonte, li dwe retabli nan eta orijinal li apre travay la fini;

(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'>transfòmatè aktyèl yo ta dwe byen okipe Pozisyon relatif la nan fil la tè dwe enstale sou ba a kòb kwiv mete tè;

(4) Sistèm pwoteksyon zewo-sekans lan ta dwe ajiste anvan pouvwa-sou asire ke pwoteksyon an travay nòmalman.