Home > Knowledge > Content

What are the checking items for main circuit of HV switchgears?

Mar 06, 2017

Check items for main circuit of HV switchgears

HV switchgear

1. Check the safety insulation distance of HV switchgear such as 10kV conductor to ground and conductor is 125mm.

2. Manufacturing and installation of primary busbar of HV switchgear should meet the requirements.

(1) Chose of materials and specification of main busbars and branch busbars should be consistent with installation table and drawings.

(2) Check color codes and color of busbars and branch busbars are right, for example, A,B, C is yellow, green and red.

(3) The treatment of busbars lap surface should meet the requirements. For example, after punching, deburring for A; the chamfer angle of double side of B is 1×45º; from lap surface of C to 10mm, no need painting; painting boundary of three-phase lapping from the same circuit should at the same horizon or vertical line, relative error should be less than 5mm.

(4) Lap surface of busbars should be flat and use 0.05mm feeler to check.

(5) Check the buabr lap bolts meet the requirements and are tight.

(6) If there is supporting insulation when the length of busbar or branch busbar is more than 1m.

3. All switchgears should have special grounding terminals, have obvious grounding mark, which should meet the requirements of products.

4. Proceed voltage withstand test to main circuit according to voltage grade.

5. Primary element check

(1) After cooperation of CB and operation mechanism, supply power to check every technical performance of CB and mechanism if they meet the requirements or not and take record. The mode and specification of installed CB should be consistent with design.

circuit breakeroperation mechanism

mechanism overview

(2) PT, CT should be consistent with the specifications of the installation table.

(3) Surge arrestors should meet the requirements of installation.

(4) The specification of disconnecting switches should meet the requirements of installation. After installation, check opening distance, contacting condition of contact after closing.

(5) Check trolley switch, observe primary plug and to-ground distance, check contact insulation.

(6) The surface painting of primary elements should be clean and shining, no falling and primer showing. The cladding should not peel off, be rusted and got mildewed.