How to use the thermal fuse correctly:
(1) Precautions for the use of fuses: ① The protective characteristics of the fuse should be compatible with the overload characteristics of the protected object. Considering the possible short-circuit current, select the fuse with the corresponding breaking capacity.
② The rated voltage of the fuse should be adapted to the line voltage level, and the rated current of the fuse should be greater than or equal to the rated current of the melt.
③ The rated current of the fuses at all levels in the line should be matched accordingly, and the rated current of the melt of the previous level must be greater than the rated current of the melt of the next level.
④The melt of the fuse should be matched with the melt as required. It is not allowed to increase the melt at will or replace the melt with other conductors.
(2) Fuse inspection inspection:
① Check whether the ratings of the fuse and the melt are compatible with the protected equipment.
② Check whether the appearance of the fuse is damaged or deformed, and whether there is any trace of flicker discharge in the porcelain insulating part.
③ Check whether the contact points of the fuse are in good condition, the contact is tight, and there is no overheating.
④ Whether the blown signal indicator of the fuse is normal.
⑶ Use and maintenance of fuse:
①When the melt is blown, carefully analyze the cause of the fuse. The possible reasons are:
1) Normal fuse due to short-circuit fault or overload operation.
2) The melt has been used for too long, and the melt has been broken by mistake due to the change of melt characteristics due to oxidation or high temperature during operation.
3) There is mechanical damage when the melt is installed, which reduces the cross-sectional area and causes false interruptions during operation.
②When replacing the melt, it is required to do:
1) Before installing a new melt, find out the cause of the melt fuse. If the cause of the melt is not determined, do not replace the melt for test delivery.
2) When replacing a new melt, check whether the rating of the melt matches the protected equipment.
3) When replacing the new melt, check the internal burn of the fuse tube. If there is serious burn, replace the fuse tube at the same time. When the porcelain melting tube is damaged, it is not allowed to replace it with another material tube. When replacing the melt of the filler-type fuse, pay attention to filling the filler.
③The fuse should be repaired at the same time as the power distribution device:
1) Clean the dust and check the contact of the contact points.
2) Check the appearance of the fuse (remove the fuse tube) for damage and deformation, and whether the porcelain parts have discharge and flicker marks. 3) Check the fuse, whether the melt matches the protected circuit or equipment, if there is any problem, it should be investigated in time.
4) Pay attention to check the N line in the TN grounding system and the grounding protection line of the equipment, and fuses are not allowed.
5) When maintaining and inspecting the fuse, cut off the power supply according to the requirements of safety regulations, and do not allow the fuse tube to be removed with electricity.
