Product Overview
The FDE outdoor oil immersed discharge coil is a single-phase tank-type unit for AC power systems at 50Hz/60Hz. Connected in parallel with the high-voltage shunt capacitor bank, it provides a defined discharge path that reduces the residual voltage of the capacitor bank to a safe value within five seconds when the capacitor group is disconnected from the system, protecting operating personnel and downstream equipment.
The live part is assembled in a sealed steel tank and immersed in transformer oil, with porcelain bushings bringing out the primary terminals. Oil insulation gives the unit excellent heat dissipation, lightning-impulse withstand capability and long service experience in outdoor capacitor bank installations. During normal operation the secondary winding functions as a voltage indicator; 3P and 6P secondary configurations are available so the winding can also feed residual-voltage relay protection for the bank.
Key Features:
- Discharges residual voltage to safe level within 5s at 4 Mvar capacity
- Sealed steel tank with mineral oil insulation and porcelain bushings
- Rated insulation level of 12/42/75 kV for reliable operation in AC
- Voltage ratio 11/√3:0.1/√3:0.1/√3 kV with 3P and 6P secondary options
- Accuracy class 0.5 with rated secondary output of 50 VA and 100 VA
- Ambient temperature range from -40°C to +40°C and max altitude of 3000m
Product Display
Model Designation
The FDE model designation follows a standardized coding system:
Example: FDE-11/√3-1.7-1W identifies an outdoor oil immersed discharge coil with secondary winding, an 11/√3 kV rated primary voltage configuration, a 1.7 Mvar matched capacitor capacity, single-phase construction, and outdoor installation.
Service Conditions
- Installation: Outdoor type
- Ambient Temperature: -40°C to +40°C
- Altitude: Not more than 3000m
- System Frequency: 50Hz / 60Hz
- Insulation Medium: Mineral oil in sealed steel tank
- Atmosphere: No corrosive gas; no conducting or explosive dust
Construction
The FDE uses a classic oil-immersed construction: the core and windings are assembled in a gasketed steel tank filled with mineral oil, and the primary leads are brought out through outdoor porcelain bushings. Oil serves both as the insulation medium and the cooling medium, giving the unit strong over-voltage capability and a stable thermal rating.
Construction Advantages: Separate secondary terminal box on tank wall for safe connection of metering and protection circuits, pressure relief valve on tank wall, earthing bolt, conforms to DLT653-2009 standard, can be built to special customer demands, weight approximately 47 kg.
Technical Data
| Type | Rated
Voltage Ratio (kV) |
Accuracy Class
& Rated Output (VA) |
Rated
Insulation Level (kV) |
Discharge
Capacity (Mvar) |
|---|---|---|---|---|
| FDE-11/√3-1.7-1W | 11/√3:0.1/√3:0.1/√3 | 0.5/3P-50/100; 0.5/6P-50/100 | 12/42/75 | 4 / <5s |
Standards
The FDE series conforms to the DLT653-2009 standard and can be built to special customer demands. The rated frequency is 50Hz/60Hz with a rated insulation level of 12/42/75 kV.
Installation & Dimensions
The FDE discharge coil stands on a flat foundation with the tank base level. Allow clearance around the tank for bushing creepage distances and for access to the secondary terminal box. Primary bushings connect to the capacitor bank neutral point and the busbar; the tank is connected to the earthing grid through the earth bolt.
Installation Diagram
Wiring Diagram
The primary winding is connected between the bank neutral and earth (or across the designated winding section) as shown in the wiring diagram. The 3P/6P secondary windings supply voltage indication and residual-voltage protection circuits. Confirm terminal markings, polarity and earthing against the approved wiring drawing before energization.
Key Outline Dimensions: Overall height 605±10 mm (bushings included, 15° V-arrangement), width over bushing terminals 355±5 mm, base plate 319 mm front-to-back × 262 mm side-to-side, mounting holes 273±2 × 216±2 mm (Ø9 mm), primary terminals 2-M10, secondary terminals 4-M10 (1a, 1n, 2a, 2n), M8 earthing bolt, pressure relief valve on tank wall, weight approximately 47 kg.