High and low voltage switchgear is a kind of electrical equipment, the external line into the cabinet main control switch, and then into the sub-control switch, each subway according to its need to set up. Such as instrumentation, automatic control, motor magnetic switch, a variety of AC contactors, etc., some also set up a high-voltage room and low-voltage room switchgear, with a high-voltage bus, such as power plants, etc., and some also have a low-week load-shedding for the protection of the main equipment.

Classification

1、Low-voltage withdrawable switchgear

2、AC low voltage distribution cabinet

3、Metal-armored move-open type switchgear cabinet

4、Low-voltage fixed separated switchgear cabinet

5、High-voltage capacitor cabinet

6、High-voltage switchgear

High and low voltage switchgear safety technology operating procedures

1、Working on the fully and partially energized panels, the maintenance equipment should be separated from the operating equipment by obvious signs.

2、The secondary winding of current transformer and voltage transformer should have permanent and reliable protection grounding.

3, in the operation of the current transformer secondary circuit work, should take the following safety measures:

3.1 It is strictly prohibited to disconnect the current circuit.

3.2 In order to reliably short-circuit the secondary coil of the current transformer, it is necessary to use short-circuit tabs and short circuits, and it is prohibited to use wire wrapping.

3.3 It is prohibited to carry out any work on the circuits and wires between the current transformer and the short-circuit terminals.

4. When working on the secondary circuit of the voltage transformer in operation, the following safety measures shall be taken:

4.1 Strictly prevent short-circuiting or grounding.

4.2 Insulated tools and insulated gloves shall be used, and the relevant relay protection device shall be deactivated before work is carried out if necessary.

4.3 When connecting temporary loads, special switches and fuses must be fitted.

4.4 When the secondary circuit is energized for testing, in order to prevent reverse voltage transformation from the secondary side to the primary side, the primary fuse should be removed in addition to disconnecting the secondary circuit.

4.5 Before the secondary circuit is energized or tested for voltage withstand, the duty officer and relevant personnel shall be notified and sent to guard the site, check the circuit and confirm that no one is working before pressurization.

4.6 The staff checking the power failure protection and secondary circuit shall not be allowed to carry out any reversing operation without the permission of the duty officer.