Precautions for the use of falling fuses

When the falling fuse is used, attention should be paid to the use of the falling fuse.

For a system of multiple distribution transformer parallel operation, in the selection of switchgear should pay special attention to the problem of the current transfer check, such as checking the calculation, if two sets of the same type, the capacity of the transformer parallel operation, if the two sides of the transformer short circuit, transformer impedance will change at this time in half only a single distribution system, so that the high voltage side maximum three-phase short-circuit current doubling should transfer current may appear also doubled. Therefore, for a system of parallel operation with multiple transformers, it is more important to check the transfer current when selecting the combined electrical appliances, and select the combined electrical apparatus that transfers the current index to meet the requirements.

Two. One of the following requirements should be equipped with a shunt tripping device to realize the fast electric switching of the load switch.

1. the oil immersed transformer for heavy gas protection should be set up. In general, heavy gas trip protection must be set up for oil immersed transformers with capacity of 800KVA and above.

2. dry type transformer overtemperature tripping protection.

The 3. - belt dry - type transformer's tripping protection.

4. has the requirement of remote operation control.

In short, the selection of switch fuse combinations, should according to the actual situation, in accordance with the transformer capacity and operation mode, combined with the technical parameters of various types of load switch and breaking capacity, calculating the transfer current and transfer current of load switch, the fuse and the transformer selection parameters, so as to make the right choice the combination of electrical appliances, to ensure safe and reliable operation of combined electrical equipment.