Rhagofalon ar gyfer gosod newidydd cerrynt dilyniant sero

1. Problemau wrth osod
(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'>y newidydd presennol ar y cebl, sy'n torri'r egwyddor o offer switsio cwbl gaeedig nid yw'n ddiogel nac yn atal llwch, heb sôn am anifeiliaid bach, gan adael llawer o beryglon cudd.

(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'>trawsnewidydd presennol, dylai'r wain metel cebl a'r wifren ddaear gael eu hinswleiddio o'r ddaear, ac mae pwynt daear y cebl (y pwynt weldio rhwng y wifren ddaear cebl a'r darian metel cebl) yn is na'r trawsnewidydd, dylai'r wifren ddaear gael ei seilio'n uniongyrchol ;

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'>trawsnewidydd presennol. Gweithred yn iawn.

(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'>Nid yw cylched magnetig y trawsnewidydd presennol ar gau ac ni all weithio'n 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'>coil eilaidd y trawsnewidydd presennol i agor.

(5) Nid yw pen sylfaen gwifren sylfaen gwain metel y cebl wedi'i weldio i'r derfynell, nac wedi'i gysylltu â'r bar copr sylfaen yn y cabinet switsh, ond mae'n cael ei lapio'n achlysurol ar bolltau corff y cabinet switsh.

2. dull gosod cywir
(1) Dylid sicrhau bod y newidydd cerrynt sero dilyniant yn cael ei ddewis > mae diamedr mewnol y trawsnewidydd presennol yn fwy na diamedr allanol pen terfynell y cebl;

(2) Try not to dismantle the zero-sequence current transformer'>trawsnewidydd presennol yn ystod y gwaith adeiladu. Os rhaid ei ddatgymalu, rhaid ei adferu i'w gyflwr gwreiddiol ar ol i'r gwaith gael ei gwblhau;

(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'>dylid trin y newidydd presennol yn iawn Rhaid gosod safle cymharol y wifren sylfaen ar y bar copr sylfaen;

(4) Dylid addasu'r system amddiffyn sero dilyniant cyn pŵer ymlaen i sicrhau bod yr amddiffyniad yn gweithio'n normal.