LFD Low Frequency Heating Device
The LFD device is designed for heating and drying transformer windings. The principle of the device functioning is based on low-frequency electric currents through the transformer windings and heating these windings to a standard drying temperature of +75… +120°C. Due to the fact that when heated by low-frequency currents, the heat source is the winding itself and the heating comes from the inside, the removal of moisture from the thickness of the insulation proceeds faster and more completely in comparison with other heating methods.
The LFD device can be used in conjunction with the CMM thermal vacuum dryers to improve the drying oil-filled transformers efficiency. In this case during the drying of the transformer there are two simultaneous processes of direct heating of the windings of the disconnected transformer and the removal of moisture which was released from the windings into the oil.
If the oil is drained from the transformer, then it is effective to use the LFD device complete with BV or UVV or Mojave Heat units, which remove moisture released from the windings into the transformer tank.
The process lasts automatically after the windings warming up to a temperature of +75… +120°C until the amount of moisture in the oil becomes less than 10 g/t (ppm).
| No. | Parameter | Value | |
| 1 | Maximum output current of the unit (AC), A | 300* | |
| 2 | Ambient temperature, °C | 0–40 | |
| 3 | Relative humidity, % | Moisture concentration not allowed | |
| 4 | Output frequency, Hz | 0.5–10 | |
| 5 | Protection rating | IP 54, IK 09 | |
| 6 | Power supply system parameters | Any on request | |
| 7 | Dimensions, mm | length | 2510 |
| width | 1400 | ||
| height | 1680 | ||
| 8 | Weight, kg | 2500 | |
* – values shown for one of the possible versions of the device. The LFD unit is custom-made. Its characteristics may vary depending on the nominal current of the primary winding of transformers, the active parts of which need to be heated.
- full automation;
- intelligent hardware;
- compact size;
- low power consumption;
- drying of transformer windings;
- windings overheating protection.
LFD GlobeCore device can be used for:
- network distribution transformers drying;
- power transformers drying machine at electric power plants;
- traction transformers drying;
- mining power transformers drying;
- marine transformers drying;
- electric oven transformers drying;
- step-up transformers drying machne in wind power plants;
- oil and gas industry transformers drying;
- airports transformers drying;
- medical transformers drying;
- railway transformers drying;
- subway transformers drying;
- seaport transformers drying;
- water treatment plants transformers drying;
- chemical factories transformers drying;
- large sports arenas lighting transformers drying;
- traffic control systems transformers drying;
- hospitals transformers drying;
- data centers transformers drying;
- military bases transformers drying;
- telecommunication towers transformers drying;
- banks transformers drying.

