RW10-12 Outdoor High Voltage Dropout Fuse High Voltage Isolation Switch Series

RW10-12 type drop out fuse detailed introduction:
Drop out fuse is the most commonly used short-circuit protection switch for branch lines and distribution transformers in 10kV distribution lines. It has the characteristics of economy, easy operation, and strong adaptability to outdoor environments. It is widely used in the primary side of 10kV distribution lines and distribution transformers for protection and equipment switching operations.
It is installed on the branch line of the 10kV distribution line, which can reduce the range of power outages. Due to its obvious disconnection point of a high-voltage drop out fuse, it has the function of an isolation switch, creating a safe working environment for the maintenance section lines and equipment, and increasing the sense of security of maintenance personnel. Installed on distribution transformers, it can serve as the main protection for distribution transformers, so it has become popular in 10kV distribution lines and distribution transformers.
Installation of drop out fuses:
During installation, the melt should be tightened to apply a tensile force of approximately 24.5N, otherwise it may cause the contact to heat up.
The installation of the fuse on the crossbar frame should be firm and reliable, without any shaking or shaking phenomenon.
The melting tube should have a downward inclination angle of 25 °± 2 ° to facilitate the rapid drop of the melting tube by its own weight when the melt melts.
The fuse should be installed on a cross arm frame with a vertical distance of not less than 4m from the ground. If installed above the distribution transformer, it should maintain a horizontal distance of at least 0.5m from the outermost contour boundary of the distribution transformer to prevent other accidents caused by the melting tube falling.
The length of the fuse tube should be adjusted appropriately, and it is required that the duckbill tongue can hold more than two-thirds of the length of the contact after closing to avoid accidental dropping during operation. The fuse tube should not be pushed to the death of the duckbill to prevent the fuse tube from falling in time after melting.
The melt used must be a standard product from a legitimate manufacturer and have a certain mechanical strength. Generally, the melt is required to withstand a minimum tensile force of 147N or more.
7 10kV drop out fuses are installed outdoors, requiring a phase to phase distance greater than 70cm.
Operation of drop out fuse:
Under normal circumstances, it is not allowed to operate drop out fuses with load, only allowing them to operate empty equipment circuits. However, branch lines of 10kV distribution lines in rural power grids and distribution transformers with a rated capacity of less than 200kVA are allowed to operate with load according to the following requirements:
During operation, two people are responsible for one person's supervision and the other person's operation. However, qualified insulated gloves, insulated boots, and goggles must be worn, and qualified insulated rods with matching voltage levels must be used for operation. Operation is prohibited in weather conditions such as lightning or heavy rain.
When pulling the brake, it is generally stipulated to first pull off the middle phase, then pull off the leeward side phase, and finally pull off the windward side phase. This is because the distribution transformer has changed from three-phase operation to two-phase operation, and the arc spark generated when the middle phase is pulled off is minimized, which does not cause a phase to phase short circuit. Next is to break the leeward phase, as the middle phase has been pulled apart and the distance between the leeward phase and the windward phase has doubled. Even if overvoltage occurs, the possibility of a phase to phase short circuit is very small. When the windward phase is finally broken, only the capacitive current to ground is generated, and the electric spark produced is already very slight.
When closing the gate, the operation sequence is reversed. Close the windward side first, then the leeward side, and finally the middle side.
Operating the melting tube is a frequent task, and if not noticed, it can cause contact burns and poor contact, leading to overheating of the contacts and annealing of the spring, resulting in even worse contact and forming a vicious cycle. So, when pulling and closing the melting tube, moderate force should be applied. After closing, carefully check that the duckbill tongue can tightly grasp more than two-thirds of the tongue length. You can use a brake lever to hook the upper duckbill and press it down a few times, then gently try pulling to check if it is closed properly. Failure to close in place or securely, insufficient pressure on the static contacts of the fuse, can easily cause contact burns or the fuse tube to fall off on its own.