Description:

Medium voltage drop out fuse  and pull loads drop fuses are outdoor high voltage protection appliances.

It is installed on the high voltage side of the distribution transformer or the branch line of the distribution wire.

 It is used as the short circuit and overload protection of the transformer and the line, 

as well as the dividing and combining load current.

The fall-type fuse is composed of two parts: insulation bracket and fuse tube. 

The static contact is installed at both ends of the insulation bracket, and the moving contact is installed at both ends of the fuse tube.

 The fuse tube is composed of an inner anti-arc tube and an outer phenolic paper tube or epoxy glass cloth tube. 

Pull load drop type fuse to enhance the elastic auxiliary contact and arc extinguishing cover, to divide and match the load current.

In normal operation of the drop fuse, the fuse tube is tensioned with the fuse to form a closed position. 

When the system fails, the fault current when the fuse quickly fused, and the formation of arc, arc extinguishing pipe by arc scorching,

 decomposition of a large number of gas, embassy formation of high pressure, and along the pipeline blowing, 

arc is quickly elongated and extinguished.

After the fuse is broken, the lower moving contact loses tension and turns twice to lock the machine, release the fuse tube, 

and the fuse tube falls down to form an obvious breaking position.

When the load needs to be pulled, the insulation rod is used to pull the moving contacts, and the active and static contacts are still in contact. 

Continue to pull the contacts with the insulation rod, and the auxiliary contacts are separated. 

An arc is generated between the auxiliary contacts, and the arc is elongated in the hood gap.

Main technical parameters of medium voltage drop out fuse:

Application:

Outdoor drop type fuses(Medium voltage drop out fuse) are suitable for 35kv and below voltage frequency 50Hz power system, 

as transmission lines, power transformers overload and short circuit protection, split rated load current only, mechanical life ≥2000 times.

Working condition:

1.Applicable to the upper limit of 40℃ and lower limit of -30℃

2. The altitude shall not exceed 1000m and the wind speed shall not exceed 35m/s

3. Fuses do not apply to the following places

3.1 places with fuel or explosion hazards.

3.2 places with violent vibration or impact.

3.3 Areas with heteroelectrochemical gas action and serious air pollution and smog.

Introduction of the structure:

The fuse is composed of two parts of the base and the arc extinguishing device, 

the arc extinguishing tube is equipped with a spring support may rotate, always make the fuse in a state of tension,

 to ensure that the arc extinguishing tube in the closing position of self-locking, line and transformer overload or short circuit,

 fuse broken, fuse quickly out of the arc extinguishing tube, 

The arc extinguishing tube is designed as a step - by - step exhaust to solve the contradiction of breaking current on the same fuse.