LVQB series current transformer has an inverted structure with SF6 gas insulation (Please see the figure). It is connected in series with electric energy measurement, measuring, and relay protection functions.
Primary coil has a through-type conducting rod structure with good dynamic and thermal stability; its maximum thermal current can be up to 63kA/3s (when primary coil is connected in series).
Primary coil passes through the center of secondary coil without flux leakage. Measurement precision can be up to 0.1 and 0.2S grades.
Secondary coil is fixed in an aluminum shielded-case by casting organic materials; measurement and protection circuits cannot be damaged by insulation breakdown.
Optimal Electrode shielded structure improves internal and external field distribution of the product. It has an excellent insulation property. Partial discharge test is carried out under power frequency test voltage.
There are two types of external insulation bushing for customers: they have excellent explosion-resistant and shock-resistant behaviors.
▲ External bushing uses silicon rubber umbrella type apron reinforced by glass fiber. Optimal external surface field makes silicon rubber avoid electrical erosion.
▲ Porcelain bushing shell with high-strength.
Secondary outlet box is a complete structure by casting the aluminum alloy; its sealing structure meets the requirement of IP55, which is dust proof, water proof and air permeable; secondary terminal for wiring uses Phoenix special terminal; it is more convenient for operations such as plug-in, pull-out and wiring etc.
Seal ring is made of imported fluorocarbon silicone rubber, it is suitable for using in the area where there is great temperature change or the environmental temperature is extreme. The leakage rate per year is less than 0.5%.
Product performance keeps changeless after severe transporting test.
Use an aluminum alloy cast case, all components including the base, connection box, stainless steel expander, and nameplate etc do not rust forever.
A density meter is installed on the base, this meter can show the gas pressure and density in the transformer (The show value is turned to be the internal gas pressure at 20℃ automatically). A signal for refilling gas is sent out when the pressure in the transformer drops down to the alarm pressure.
Rated voltage: 35kV~500kV
Rated frequency: 50/60 Hz
Internal insulating medium: SF6 gas
Rated primary current: Up to 4000A
Short-time thermal current: Up to 63kA/3s
Insulator: Porcelain or polymer
Altitude: ≤3000m, others on request
Specific creepage distance: 31mm/kV, others on request