I.  Overview

FL (R) N36-12D indoor AC high-voltage sulfur hexafluoride load switch and load switch fuse combination electrical device. Meets the requirements of GB3804 "30-63kV AC High Voltage Load Switches", GB16926 "High Voltage Load Switches Fuse Combination Electrical Appliances", IEC60265-1, and IEC60420 standards. This product has a three position arc extinguishing chamber with "closing opening grounding", reliable interlocking, high insulation strength of the fracture, large creepage distance design, and the output end is protected by a voltage equalizing protective cover.

FLN36-12D (B) indoor AC high voltage sulfur hexafluoride load switch, its outgoing end can be connected to the front connector of the European cable, and the incoming and outgoing lines can be installed with cables and used in cable branches (boxes). The special dynamic and fixed sealing design of the switch ensures reliable sealing, and a pressure gauge is installed in a prominent position for monitoring during operation, ensuring safe operation. It is a new generation of high-voltage switchgear equipment for urban power grids.

This product is suitable for use in three-phase AC 10kV, 50Hz power systems as industrial and mining enterprises, high-rise buildings, residential areas, and Prefabricated Substations. It is used to disconnect and close load currents, fault currents, control and protect lines and distribution transformers.

II. Operating environmental conditions

a) Surrounding air temperature: -15 ° C~+40 ° C;

b) Altitude: not exceeding 1000m;

c) Humidity conditions: The average daily relative humidity should not exceed 95%, the average monthly relative humidity should not exceed 90%, the average daily water vapor pressure should not exceed 2.2 kPa, and the average monthly water vapor pressure should not exceed 1.8 kPa;

d) The surrounding air is not significantly polluted by dust, smoke, corrosive and flammable gases, vapors or salt spray;

e) Vibration or ground motion from outside the switchgear and control equipment can be ignored;

f) The amplitude of electromagnetic interference induced in the secondary system shall not exceed 1.6kV.

III. Structure

-- The load switch and combination device consist of an insulated epoxy shell body, a spring operated mechanism, a fuse contact seat, and a fuse action impact release system. The load switch for the touchable cable front joint is composed of a dedicated insulated body switch body and a universal spring operated mechanism.

-- The upper and lower shells are made of epoxy resin injection molding, forming an inflatable cavity. The moving contacts in the cavity are shared, and the positions of the upper and lower static contacts and the grounding static contact can be cycled to complete the "closing opening grounding" three working states. When the grounding position is not needed, the grounding static contact can be omitted, but it should be specified when ordering.

-- The inflation chamber is filled with pure SF6 gas at 0.04~0.05MPa (20 ° C), and after strict inspection, the expected working life that can ensure sealing is 20 years.

-- The front of the mechanism box is equipped with a gas pressure gauge and position indicator, which is used to monitor changes in SF6 gas pressure. The position indicator device is directly connected to the transmission shaft of the moving contact, indicating the reliable working position of the moving contact.

IV, Arc extinguishing principle of load switch

SF6 gas has excellent arc extinguishing performance. In order to quickly extinguish the arc, the switch generates an arc as soon as the moving and stationary contacts separate during the process of breaking the current. At this time, due to the magnetic field of the permanent magnet, the arc is driven to move rapidly, causing it to elongate and continuously combine with SF6 gas, which is quickly dissociated and cooled. It extinguishes when the current is foggy, and the double break distance has insulation level of isolated break. The permanent magnet rotary arc principle has low operating power, strong arc extinguishing ability, light contact burns, and long electrical life.