Air Cooling Epoxy Resin Dry Type Transformer

What is it?

The Air Cooling Epoxy Resin Dry Type Transformer is a completely oil-free power conversion device where all high and low voltage windings are fully encapsulated in cast epoxy resin under vacuum pressure. Unlike conventional transformers that rely on mineral oil or synthetic liquids for insulation and cooling, this unit uses only air as the cooling medium — either natural convection (AN) or optional forced air (AF). The epoxy resin serves triple duty: primary electrical insulation, mechanical protection against moisture and contaminants, and a rigid structure that withstands short-circuit forces.

What does it do?

Voltage Transformation : Steps down medium voltage (6kV, 10kV, 20kV, 35kV) to utilization voltages (208V, 400V, 480V, 690V) for industrial, commercial, and residential loads. Alternatively, steps up voltage for renewable energy grid interconnection.

Fire-Safe Power Distribution : Delivers electricity inside buildings, underground parking garages, hospitals, and data centers where oil-filled transformers are prohibited by fire codes. The self-extinguishing epoxy (UL 94 V-0 rated) will not propagate flames.

Clean Power for Sensitive Loads : Provides isolation between primary and secondary circuits, filtering harmonics, suppressing surges, and eliminating ground loops that disrupt medical imaging equipment, CNC machines, and laboratory instruments.

Outdoor & Harsh Environment Operation : With optional IP54 or IP65 enclosures, the transformer withstands rain, snow, dust storms, salt spray, and temperature extremes from -30°C to +55°C without performance degradation.

In essence, the Air Cooling Epoxy Resin Dry Type Transformer is the preferred choice whenever safety, environmental compliance, and long-term reliability are non-negotiable.

Product Parameter (Specification)

Product Feature And Application (Q&A Format)

Q1: What makes epoxy resin insulation superior to open-wound designs?

A: Three key advantages. First, moisture immunity — epoxy is non-hygroscopic. The Air Cooling Epoxy Resin Dry Type Transformer restarts instantly after weeks of shutdown in 100% humidity, while open-wound units require preheating. Second, contamination protection — conductive dust cannot penetrate solid epoxy surfaces, eliminating tracking and flashover risks. Third, mechanical strength — encapsulated windings withstand short-circuit forces up to 25× rated current without deformation.

Application: Data Centers — Zero dust accumulation risk, quiet operation below 55dB, and self-extinguishing epoxy meet NFPA 75 requirements for IT equipment rooms.

Q2: How does it perform outdoors without oil?

A: With IP54/IP65 enclosures (stainless steel, sloped rain roof, labyrinth ventilators), the transformer resists rain, dust, and salt spray. Epoxy windings resist corrosion better than oil-filled radiators. For coastal sites, 316 stainless steel enclosures are available.

Application: Solar Farms & Wind Parks — Remote, unstaffed locations benefit from zero oil sampling, zero leak inspections, and no fire suppression systems. Units operate unattended for years in temperature extremes from -30°C to +55°C.

Q3: Can it handle motor starting surges and overloads?

A: Yes. Class H (180°C) insulation allows 110% continuous overload under natural cooling (AN), and 130% for 30 minutes. With forced air (AF) option, capacity increases 20-25% — fans auto-start at 80°C. For severe cyclic overloads exceeding 150%, consult our engineers.

Application: Industrial Manufacturing — Automotive assembly lines and stamping plants experience severe load swings. Low impedance (4-6%) maintains voltage regulation within ±3%, while epoxy windings withstand vibration that would crack oil-filled radiator welds.

Q4: Is it truly maintenance-free?

A: The core transformer requires no oil changes, no dielectric testing, no filtration, no gasket replacement. Only three simple checks every 12-24 months: clean louvers/fans with compressed air, torque-check terminals, and inspect enclosure. Total annual effort: under two hours by a qualified electrician.

Production Details — What Makes Lugao Superior to Competitors

Frequently Asked Questions (Q&A)

Q1: What is the actual efficiency of the Air Cooling Epoxy Resin Dry Type Transformer, and does it degrade over time?

A: Efficiency at 75% load (typical operating point) is 98.7% for a 1000kVA unit, rising to 99.1% for a 2500kVA unit. The efficiency is determined by core loss (constant, depends on silicon steel quality) and copper loss (varies with load squared). The key advantage of the Air Cooling Epoxy Resin Dry Type Transformer is that efficiency does not degrade over time because the epoxy encapsulation prevents moisture ingress that would increase loss. Oil-filled transformers often see efficiency decline after 10-15 years as oil degrades and paper insulation moisture content rises. Our epoxy units maintain factory efficiency for the entire 30+ year service life. We provide guaranteed loss values with every unit and will reimburse the difference if field testing shows higher losses within warranty period.

Q2: How do I select the correct capacity for my application?

A: Calculate your total connected load in kVA, then apply diversity factors. For continuous loads (lighting, HVAC, servers), use 100% of nameplate. For intermittent loads (motors, welders, elevators), use 50-70% depending on duty cycle. Then add 20-25% future expansion margin. Example: A factory with 800kVA of continuous load + 400kVA of motor load (diversity factor 0.6 → 240kVA) + 20% expansion = (800+240)×1.2 = 1248kVA → select 1250kVA or 1500kVA. Over-sizing increases initial cost and no-load loss; under-sizing causes overheating and premature failure. Our engineers provide free sizing assistance — simply send your load list and duty cycles. For motor-heavy applications, we recommend forced air cooling (AF) to handle starting surges without exceeding temperature rise limits.

Q3: Can the transformer be installed in a confined space like a tunnel or vault?

A: Absolutely. The Air Cooling Epoxy Resin Dry Type Transformer is ideal for confined spaces because it requires no oil containment vault (saving 2-3 meters of clearance on all sides). The minimum clearance for ventilation is 300mm on all sides and 600mm above. For tunnel installations, we offer a low-profile version where the enclosure height is reduced by 200mm (cooling louvers relocated to sides rather than top). However, ambient temperature in tunnels can be elevated due to other equipment — we will perform a thermal analysis to confirm adequate cooling. If natural convection is insufficient, the AF (forced air) option with fans mounted directly to the core frame provides additional cooling without increasing footprint.

Why Choose Lugao Power?

Advanced Manufacturing: Supported by advanced production equipment and testing methods.

Certified Quality: ISO 9001 and SGS certified; key products hold CCC and CE certifications.

Factory Testing: Products undergo quality inspection and testing before shipment.

Project Experience: Equipment is used in power grids, industrial facilities, mining, railways, construction, and community power projects.

Technical Support: Professional support from product selection and customization to delivery.