Purpose and Scope of Application
Collective capacitors and parallel capacitors with large single capacity mainly rely on internal fuses to isolate faults and ensure the continued operation of capacitors due to internal component failures. Due to the unbalanced voltage of capacitors, the voltage on non fault phase capacitors and healthy components in fault phases will increase. When a single star shaped parallel capacitor group is connected to each phase capacitor using two or more series sections or a collective capacitor with a middle tap, its internal protection can also use high-sensitivity differential pressure protection. The discharge coil with a middle tap is connected to the corresponding tap of each phase capacitor to form a differential pressure protection circuit, which can act on the switch to promptly remove the capacitor from the grid when the voltage on the healthy component exceeds the allowable safe working value. The FDR3C fully sealed discharge coil is a all-weather product designed specifically for this differential pressure protection wiring method, with ideal discharge performance. And ensure its protection sensitivity requirements with its high differential pressure measurement precision.  
FDR3C fully sealed discharge coil, high-voltage coil with center tap A2, suitable for parallel capacitors (groups) using differential pressure protection. A2 is connected to the corresponding middle terminal of the capacitor (group), and its voltage corresponds to 50% of the voltage of A1 and X at the middle tap of the parallel capacitor (note: other corresponding values can also be designed according to user requirements, such as the voltage ratio of A1, A2, X being 4:6 or 6:4 or other values).  

Structure and performance characteristics
a. The FDR3C fully sealed discharge coil adopts two independent high-quality iron cores, a fully insulated structure, and each has a secondary coil. The structure is reasonable, the power consumption is low, the temperature rise is low, and the accuracy requirements of differential pressure protection are ensured.  
b、 The fuel tank adopts a fully sealed horizontal structure, vacuum dried oil injection, reliable sealing performance, and ensures complete isolation from the outside air. Its insulation oil compensation method adopts advanced compensation technology with a unique structure. Regardless of whether it operates at the highest or lowest temperature of the environment throughout the year, the pressure inside the tank always maintains a slight positive pressure (no more than 0.005Mpa at the highest and no less than 0.001Mpa at the lowest).
c、 The sealing performance of the horizontal fuel tank body and ceramic sleeve is reliable, and there is no need for maintenance or replacement of components during the expected service life, ensuring no oil leakage and explosion-proof function. It is a maintenance free product.  

Main technical parameters of FDR3C-35kV outdoor discharge coil

Environmental conditions for use
a. Usage conditions: outdoor and indoor, ambient temperature;
Class A -40~+40 ℃
Class B -25~+45 ℃
Class C -10~+55 ℃
b. Altitude not exceeding 1000m
c. Seismic resistance level: Under the action of an earthquake intensity of 8 degrees, it will be damaged.
d. Installation location: No harmful gases, vapors, or conductive or explosive dust.
e. Maximum wind speed 35m/s

Connection method with capacitor (group)

Outline installation dimension diagram




FDR3C-35kV outdoor discharge coil