10kV 12kV Outdoor medium voltage windproof type cut-out fuse composite drop-out fuse cutout

10kV 12kV Outdoor medium voltage windproof type cut-out fuse composite drop-out fuse cutout

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• Drop-out fuses are suitable for power systems with a frequency of 50HZ and a rated voltage of 35KV and below, and are installed on the high-voltage side of distribution transformers or on the main lines of distribution. The main function is where the protection performance is not high, it can be used in conjunction with the isolating switch to replace the automatic air switch; it can also be used in conjunction with the load switch to replace the expensive circuit breaker. It also has short circuit protection, overload and isolation circuits.

  The high-voltage drop-out fuse consists of three parts: insulating support, dynamic and static contacts, and fuse tube. The static contacts are installed at both ends of the insulating support, and the fuse tube is composed of an inner arc suppression tube and an outer phenolic paper tube or epoxy glass fiber cloth tube.

  Working principle

  The load drop fuse has added elastic auxiliary contacts and arc extinguishing cover to break the load current. When the drop fuse is in normal operation, the fuse tube is tensioned by the fuse to form a closed position. When a fault occurs in the system, the fault current causes the fuse to be blown quickly and an arc is formed. The arc suppression tube is heated by the arc and decomposes a large amount of gas, which makes a high pressure in the tube, and blows strongly along the pipeline, and the arc is quickly elongated and extinguished. After the fuse is blown, the lower static contact loses tension and turns down, so that the tightening mechanism releases the fuse tube, and the fuse tube falls to form an obvious breaking position. When the load needs to be pulled, use the insulating rod to open the moving contact, at this time the active and static contacts are still in contact, continue to use the insulating rod to pull the contact, the auxiliary contact is also separated, an arc is generated between the outlets, and the arc is extinguished The slit of the cover is elongated, and at the same time, the arc extinguishing cover generates gas, and when the current crosses zero, the arc is extinguished.

  Installation requirements

  1. The fuse should be installed vertically to prevent the arc from falling on the adjacent live parts.
  2. The fuse and the fixed contact should be in contact with each other in a straight line and without inclination.
  3. For drop-type fuses, the axis of the melting tube should be 15~30° from the vertical line, and its rotating part should be flexible, and it should not touch other objects when falling.
  4. The specifications of the fuse should meet the design requirements, there should be no bending, flattening or damage, and the fuse and the contact should be pressed tightly and firmly.
  5. The rated current of the fuse and the fuse (wire or sheet) must be marked on the fuse. The capacity of the fuse should meet the requirements of the protected electrical appliance. The fuse that has not been verified or marked with no rated current is not allowed to be used.

  Normal use environment.

  a) Ambient air temperature: upper limit +40°C, lower limit -30°C;
  b) The altitude does not exceed 1000m;
  c) The maximum wind speed does not exceed 35m/s;
  d) There is no frequent violent vibration.
  2. The product is not suitable for the following places:
  a) Places where there is a danger of burning or explosion;
  b) Places with severe vibration or shock;
  c) Areas with electrical conductivity, chemical gas effect, serious pollution (not exceeding pollution level: Grade III), and salt fog.

  Drop Fuse Applications

  

   

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