Continuous Duty 11/0.4kV Dry Type Distribution Transformer 200kVA for Fluctuating High Load Production Processes

Design Measure: Core and coil assemblies are locked together with heavy-duty structural clamps and vibration-damping pads. The cast resin winding, heavily reinforced with embedded glass fiber, transforms the coil into a monolithic block that resists microscopic cracking even after millions of mechanical shocks.

Technical Highlight: This solid composite structure withstands the dynamic forces of short circuits and motor starting without deformation, maintaining clamping pressure and insulation integrity over decades.

Design Measure: The winding uses an oversized conductor cross-section with multiple axial cooling channels, effectively turning the coil into a heat exchanger with a long thermal time constant. A dual-sensor temperature controller stages forced air fans based on real-time winding temperature, not just ambient.

Technical Highlight: With fans active, the transformer can safely deliver up to 150% rated current, absorbing successive peak loads while the winding temperature climbs gradually and stays within insulation class limits.

Design Measure: An optimized low-impedance design (typically 4% or customized) keeps voltage regulation tight, and the Dyn11 connection provides a low zero-sequence impedance path, holding the 0.4kV system neutral stable even during highly unbalanced single-phase draws from lighting and auxiliary circuits.

Technical Highlight: The Dyn11 group circulates zero-sequence flux internally, removing voltage distortion and overheating from third-harmonic currents, which is critical when countless variable speed drives and rectifiers share the same power bus.

Design Measure: The complete HV winding is enveloped in hydrophobic epoxy resin, making it impervious to moisture, metallic dust, and light chemical vapors. With an optional IP23 enclosure and intake filters, operators can wash down the area without compromising insulation.

Technical Highlight: Anticondensation heaters controlled by the temperature monitor prevent dew formation inside enclosures during production stops, guaranteeing instant readiness when lines restart.

Yes. The Dyn11 winding and oversize cross-section handle high inrush currents without excessive voltage drop, and the reinforced structure withstands the associated mechanical forces. The thermal inertia of the cast resin mass absorbs the heat pulse, and the smart cooling fans activate to dissipate it before the next cycle begins.

The internal Pt100 sensors feed real-time winding temperature to the digital controller. Once it reaches the fan-on setpoint, cooling fans switch on automatically. With AF cooling, the transformer can continuously carry up to 150% of rated 200kVA, giving your production operators generous peak-load headroom without nuisance tripping.

The standard Dyn11 connection is inherently effective at containing zero-sequence harmonics on the delta side. For facilities with a very high total harmonic distortion, we can provide a custom-designed K-factor rated version with additional de-rating margin and a double-shielded LV winding to protect against extra heating.

There is practically no dismantling or fluid service. Technicians should visually check the winding surfaces, confirm bolt torque on terminations, clean any dust from insulation surfaces and fan guards with a dry cloth or low-pressure air, and verify that the temperature controller functions correctly. The process takes minutes, not hours.

Absolutely. There is no oil, so fire risk is drastically reduced and floor sealing and oil containment pits are unnecessary. The solid epoxy resin is flame-retardant and extinguishes itself when the ignition source is removed, meeting strict insurance and occupational safety requirements for placement inside occupied manufacturing zones.

We deliver precise GA and civil works drawings, ventilation clearance data, and electrical schematics for the temperature controller interface. Terminal boxes are pre-wired for alarm, trip, and 4-20mA remote monitoring signals, allowing seamless connection to your plant's PLC or SCADA network.