Provisions for installation of drop fuses

1. porcelain should be good, fuse tube should not be moisture absorption expansion, bending phenomenon. 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 without twisting.

2. The drop type fuse should be installed firmly with special metal tools, arranged neatly, and should not be rotated left or right. The horizontal distance between two stages should not be less than 0.5m. In order to facilitate operation and fuse fuse pipe self-fall, the Angle between the axis of the porcelain base and the vertical line on the ground is generally 20o ~ 30o.

3. The operation of dividing and closing should be flexible, reliable and close in contact. Before closing, the upper and lower contacts should be adjusted with a certain compression stroke.

4. The connection between the upper and lower leads and the drop switch should be firm and the contact should be good. Appropriate extra lines should be left at the connection point with the line.

Precautions for installation of drop type fuse

1. Check before installation:

(1). Should check whether the fuse specifications and models are appropriate, there is no manufacturer and factory certificate.

(2) Whether the fuse parts are complete and intact, and whether the porcelain parts are cracked or damaged.

(3) Whether the static contact is good, and whether the elasticity of the static contact is moderate.

2. Installation of fuse:

(1) In order to facilitate operation, the installation height of the fuse should generally be between 4.5 ~ 5m.

(2). The Angle between the fuse fuse tube and the horizontal plane should be kept at 60 degrees ~ 75 degrees.

(3). The phase distance of the drop fuse should meet the requirements of the regulations.

(4). The upper and lower leads of the drop fuse should be connected reliably and have good contact.

(5). When copper is connected to aluminum, use copper-aluminum transition clamp.

Installation regulations and requirements for drop fuses

3. the choice of fuse:

(1). High voltage fuse with manufacturer, production date and product certificate should be used.

(2). Under normal circumstances, transformers 125KVA and below can be selected by 2 ~ 3 times of the rated current on the high voltage side; Transformers of 125 ~ 400KVA can be selected by 1.5 ~ 2 times of the rated current on the high voltage side. Transformers above 400KVA can be selected according to 1.5 times of the rated current on the high voltage side; By calculation, when the fuse is less than 5A, considering the mechanical strength, it can be selected by 5A.

(3) It is strictly prohibited to use copper or aluminum wire instead of high voltage fuse.

4. Operation of fuse

(1). Operators should wear insulating boots and insulating gloves during operation, and use suitable and qualified insulating rods with voltage grade.

(2). Before operation, the switch on the low voltage side of the transformer should be disconnected.

(3).Pull the fuse to follow: when pulling the brake, first pull the middle phase, then pull the leeward phase, and finally pull the windward phase; The sequence of closing operation is opposite to the sequence of pulling.

(4). When pulling the switch, the action should be accurate, rapid and decisive.