What are the requirements for low frequency heating equipment for manufacturing special transformers and air core reactors?

A typical low-frequency heating unit for transformer winding drying is designed to heat windings to roughly +75°C to +120°C by passing low-frequency AC through the coils; units commonly provide adjustable frequencies from about 0.5 Hz to 10 Hz, AC output voltages up to ~400 V (automatic control) and output currents in the low-hundreds of amps (specs are typically up to 300 A AC, with sinusoidal output ratings commonly quoted to ~200 A depending on configuration). These units are intended to run in dry ambient conditions (0°C to 40°C), have ingress and impact protection (typical ratings IP54 and IK09), and often include automatic process control that continues heating until oil moisture reaches a target (commonly cited as <10 g/ton). They can be used alongside thermal vacuum dryers to speed moisture transfer from windings into oil, and power-supply parameters can usually be customized to customer needs.

Limitations and practical requirements to observe are straightforward: do not operate the equipment with internal moisture or condensation, verify the exact current/frequency ratings for your configured unit, and ensure ambient and enclosure protection are suitable for your site. The published capability set focuses on heating transformer windings; there is no explicit specification for air-core reactors or special transformer manufacturing in the standard product data, so for air-core reactors or atypical winding geometries you should confirm the heating method, required current/voltage, impedance and insulation class with the vendor or engineering team before applying LFD-style low-frequency heating.

A suitable GlobeCore solution for manufacturing of special transformers and air-core reactors involves low frequency drying which is designed for controlled heating and drying of transformer windings with the use of low-frequency currents. The main advantage of this technology is that the heat is generated directly inside the winding, providing uniform temperature distribution and efficient moisture removal from the insulation system.
For factory production processes, the LFD system can be integrated with vacuum drying equipment such as the US-6S vacuum drying oven when deeper drying of insulation components is required. The final configuration should be selected according to the transformer design, winding dimensions, insulation materials, required drying parameters, and production cycle requirements.

Your summary is accurate: low-frequency heating heats windings from within, giving uniform temperature distribution and efficient moisture removal from the insulation system, and it is well suited for manufacturing special transformers and air-core reactors where controlled, repeatable drying is required. Typical LFD operating parameters to verify for any production integration are heating temperature range (about +75°C to +120°C), adjustable output frequency (commonly 0.5–5 Hz or 0.5–10 Hz depending on the model), AC output voltage control in the 0–400 V range, and output currents in the low hundreds of amps (model-dependent — documented units show max input current up to ~185 A and output current ratings commonly around 200 A, with some configurations up to ~300 A). The units are designed for dry shop environments (ambient 0°C–40°C, no internal condensation) and typically carry IP54/IK09 protection and automatic process controls that can continue drying until oil moisture falls below ~10 ppm.

For factory production you should select the final LFD configuration to match winding geometry, impedance, insulation class, required target temperatures and production cycle times, and confirm the LFD’s frequency/current capability for low-impedance air-core coils (which often demand higher current). Plan integration with the US-6S vacuum drying oven or similar vacuum bake steps for deeper moisture removal, and define the process sequence, temperature and moisture setpoints, thermocouple placement, grounding and safety interlocks, and monitoring/recording requirements for quality control. Finally, validate the chosen configuration with the vendor and perform FAT/PAT cycles on representative parts to confirm heating uniformity, current paths, insulation temperatures and cycle timing before full production rollout.