Product Overview
The FDGE8 semi-enclosed dry type discharge coil is an single-phase epoxy resin vacuum-cast, single-phase indoor product for AC power systems at 50Hz with a rated voltage of 10kV and below. Connected in parallel with the high-voltage shunt capacitor bank, it reduces the residual voltage of the capacitor bank to a safe value within five seconds when the capacitor group is disconnected from the system. During normal operation the secondary winding functions as a voltage indicator; where users require it, a residual voltage winding can be provided to deliver relay protection.
The coil adopts an iron-core semi-casting structure in which the core is built from high-grade silicon-steel sheets. The result is a compact, light-weight unit with low no-load loss, strong resistance to over-voltage, and convenient installation that requires no maintenance. It is designed as a maintenance-free replacement for conventional oil-immersed discharge coils in capacitor bank compensation installations.
Key Features:
- Rated voltage 6.6-12kV with discharge capacity from 1.7 to 3.4 Mvar
- Accuracy class 0.2, 0.5, or 1 with rated secondary output up to 100VA
- Discharges capacitor residual voltage to safe value within 5 seconds
- Iron-core semi-casting structure built with silicon steel sheets
- Rated insulation level up to 12/42/75kV with >300mm creepage distance
- Secondary winding provides voltage indication and optional relay output
Product Display
Model Designation
The FDGE8 model designation follows a standardized coding system:
Example: FDGE8/11/√3-2.5-1 denotes a dry-type discharge coil with secondary winding, design No.8, rated primary voltage 11/√3 kV, matched capacitor capacity 2.5 Mvar, single phase.
Service Conditions
- Installation: Indoor type
- Ambient Temperature: -5°C to +40°C
- Altitude: Not more than 1000m
- System Frequency: 50Hz
- Atmosphere: No corrosive gas or smoke; no conducting or explosive dust
- Vibration: No severe mechanical vibration at the installation site
- Relative Humidity: Monthly average ≤ 90%; daily average ≤ 95%
Construction
The FDGE8 uses an iron-core semi-casting (semi-enclosed) structure. The magnetic core is stacked from high-grade silicon-steel sheets to keep no-load loss low and to provide strong over-voltage withstand capability. Windings are encapsulated by epoxy resin vacuum casting, giving a moisture-proof, maintenance-free insulation system suited to indoor switchgear and capacitor compartments.
Construction Advantages: Semi-enclosed frame keeps the unit compact and light while allowing convenient mounting; base fixing holes and terminal arrangement suit standard capacitor bank layouts, maintenance-free design.
Technical Data
| Type | Rated
Voltage (kV) |
Accuracy Class
& Rated Output (VA) |
Discharge
Capacity (Mvar) |
Rated
Insulation Level (kV) |
|---|---|---|---|---|
| FDGE8/6.6/√3-1.7-1 | 6.6/√3/0.1 | 0.2→20; 0.5→50; 1→100 | 1.7 | 7.2/32/60 |
| FDGE8/7.2/√3-1.7-1 | 7.2/√3/0.1 | 0.2→20; 0.5→50; 1→100 | 1.7 | 7.2/32/60 |
| FDGE8/11/√3-1.7-1 | 11/√3/0.1 | 0.2→20; 0.5→50; 1→100 | 1.7 | 12/42/75 |
| FDGE8/11/√3-2.5-1 | 11/√3/0.1 | 0.2→20; 0.5→50; 1→100 | 2.5 | 12/42/75 |
| FDGE8/11/√3-3.4-1 | 11/√3/0.1 | 0.2→20; 0.5→50; 1→100 | 3.4 | 12/42/75 |
| FDGE8/12/√3-1.7-1 | 12/√3/0.1 | 0.2→20; 0.5→50; 1→100 | 1.7 | 12/42/75 |
| FDGE8/12/√3-2.5-1 | 12/√3/0.1 | 0.2→20; 0.5→50; 1→100 | 2.5 | 12/42/75 |
| FDGE8/12/√3-3.4-1 | 12/√3/0.1 | 0.2→20; 0.5→50; 1→100 | 3.4 | 12/42/75 |
Standards
The FDGE8 series conforms to the DL/T 653-1998 standard (Specification of discharge coils for high voltage parallel connection capacitor for order). Load power factor: cosφ 0.8 (lagging), surface creepage distance: more than 300mm.
Installation & Dimensions
The FDGE8 discharge coil is designed for indoor installation. Overall dimensions: top width 180 mm; height 530±5 mm; base mounting 90/200±1 mm (front), 170/230±1 mm (side). Refer to the approved outline drawing before foundation and busbar work.
Installation Diagram
Wiring Diagram
The primary winding is connected in parallel across the high-voltage capacitor bank terminals (phase to neutral/earth point of the bank). The secondary winding supplies voltage indication; where fitted, the residual voltage winding connects to the protection relay. Confirm terminal markings, polarity and earthing against the approved wiring drawing before energization.