1. The porcelain parts should be good, and the fuse tube should not have moisture absorption, expansion, or bending. The center line of the upper and lower contacts of the fuse tube and the axis of the fuse tube should be in the same plane and must not be twisted.
2. The drop-out fuse should be installed firmly with special fittings, arranged neatly, and cannot be rotated left and right, and the horizontal distance between phases should not be less than 0.5m. In order to facilitate the operation and self-fall of the fuse tube, the angle between the axis of the porcelain seat and the vertical line of the ground is generally 20o to 30o.
3. The opening and closing operations should be flexible, reliable and close in contact. There should be a certain compression stroke to adjust the upper and lower contacts before closing.
4. The connection between the upper and lower leads and the drop switch should be firm and the contact should be good. Appropriate remaining line should be left at the connection point with the line.
Installation requirements for drop-out fuse
1) Porcelain parts should be good, and the molten pipe should not have moisture absorption, expansion or bending. The centerline of the upper and lower contacts of the fuse tube and the axis of the fuse should be in the same plane and must not be twisted.
2) The drop-out fuse should be installed firmly and neatly with special fittings, and should not be rotated left and right, and the horizontal distance between phases should not be less than 0.5m. In order to facilitate the operation and the fuse to blow and fall, the angle between the axis of the porcelain seat and the vertical line of the ground is generally 20°-30°.
Precautions for installation of drop-out fuse
1. Check before installation:
①. Check whether the specifications and models of the fuse are appropriate, whether there is a manufacturer and factory certificate.
②. Whether all parts of the fuse are complete and intact, whether there are cracks or damages in the porcelain parts.
③. Whether the dynamic and static contacts are in good contact, and whether the static contacts have moderate elasticity.
2. Installation of the fuse:
①. In order to facilitate the operation, the installation height of the fuse should generally be between 4.5 and 5m.
②. The angle between the fuse pipe and the horizontal plane should be maintained at an angle of 60 degrees to 75 degrees.
③. The distance between the phases of the drop-out fuse must meet the requirements of the regulations.
④. The upper and lower leads of the drop-out fuse should be connected reliably and in good contact.
⑤. When copper and aluminum are connected, use a copper-aluminum transition clamp.
3. The choice of fuse:
①. Use high-voltage fuse with manufacturer, production date and product qualification certificate.
②. Generally, transformers of 125KVA and below can be selected according to 2~3 times of the rated current of the high voltage side; transformers of 125~400KVA can be selected according to 1.5~2 times of the rated current of the high voltage side; transformers above 400KVA , Can be selected according to 1.5 times the rated current of its high voltage side; through calculation, when the fuse is less than 5A, considering the mechanical strength, it can be selected according to 5A.
③ It is strictly forbidden to use copper and aluminum wires instead of high-voltage fuses.
4. The operation of the fuse:
①. Operators should wear insulating boots, insulating gloves, and use insulating rods with appropriate and qualified voltage levels.
②. Before operation, all switches on the low voltage side of the transformer should be disconnected.
③. The closing of the fuse should follow: when opening the switch, first open the middle phase, then the leeward phase, and finally the windward phase; the closing operation sequence is opposite to the opening sequence.
④. The action should be accurate, fast and decisive when pulling and closing.
Post time: Jan-19-2022