1. Product Overview
This 630kVA 20/0.38kV three phase dry type distribution transformer is engineered for continuous, reliable power delivery in tropical climates and harsh industrial environments. Vacuum cast epoxy resin windings provide inherent resistance to high humidity, extreme ambient heat and airborne conductive dust. The oil free, self extinguishing design eliminates fire hazards and simplifies installation, making it a robust distribution solution for factories, processing plants and EPC projects operating under severe conditions.
2. Key Advantages
Moisture and Corrosion Resistance
Epoxy encapsulated windings do not absorb moisture, preventing insulation degradation even at saturated humidity levels. The cast construction also withstands chemical vapors and saline air found in coastal and industrial zones.
High Temperature Endurance
Class H insulation system (180°C) with a conservative temperature rise limit of Class F (155°C) allows full load operation under ambient temperatures up to 50°C. The transformer maintains rated 630kVA output without derating in tropical heat.
Conductive Dust Protection
Solid cast coil surfaces eliminate internal dust accumulation. With optional IP54 enclosures and sealed cable boxes, the unit prevents conductive dust from creating tracking paths, preserving insulation integrity in textile mills, cement plants and metal workshops.
Energy Efficient Performance
Low no load and load losses help reduce electricity consumption and operating costs, aligning with IEC 60076 and global energy conservation standards for industrial power distribution.
Low Maintenance and Quiet Running
With no oil to sample or filter, maintenance is minimal. The rigid cast structure dampens vibration and reduces acoustic noise, contributing to a better work environment on production floors.
3. Technical Specifications
Rated Capacity:
630kVA (custom capacities available)
Primary Voltage:
20kV with off circuit taps ±2×2.5% or as specified
Secondary Voltage:
0.38kV (380V) or 400V/415V to match local grid requirements
Phase and Frequency:
Three phase, 50Hz or 60Hz
Vector Group:
Dyn11 (standard), Yyn0 or others upon request
Insulation Class:
H (180°C), temperature rise limited to Class F (125K)
Cooling Method:
AN (natural air) with optional AF (forced air) for temporary overload capability
Winding Material:
Copper or aluminum, vacuum cast with epoxy resin for void free solid insulation
Core:
High permeability grain oriented silicon steel, step lap mitred core for low loss and low noise
Enclosure Protection:
Standard IP20 for indoor installation; IP44, IP54 and outdoor canopies available
Accessories:
Winding temperature controller with alarm and trip contacts, forced air cooling fans, anti condensation heaters optional
Standards:
IEC 60076-11, ISO 9001, and can be manufactured to comply with SNI, PLN or other local utility regulations
Partial Discharge:
Extremely low values, ensuring long insulation life and suitability for sensitive applications
4. Environmental Solutions for Tropical and Harsh Industrial Conditions
High Humidity Defense
The epoxy cast winding is a void free, non hygroscopic mass that does not absorb water. Even if the transformer stands idle in a saturated atmosphere, insulation remains intact. For outdoor or unheated indoor installations, we can embed anti condensation heaters that activate automatically to keep coil surfaces dry during shutdowns. No preheating is required before energization.
Extreme Heat Mitigation
Optimized air duct geometry inside the cast coils maximizes natural convection cooling. With Class H insulation and Class F temperature rise, the transformer operates continuously at full rated capacity under 50°C ambient. Optional forced air cooling provides an additional margin during occasional heat waves or temporary overloads without sacrificing insulation life.
Conductive Dust Protection
The fully solid winding surface has no crevices for particle adhesion. In heavy dust environments such as cement grinding mills or textile spinning rooms, IP54 sealed enclosures and gasketed terminal boxes keep abrasive and conductive dust away from live parts. The absence of exposed bare conductors makes surface tracking and flashover extremely unlikely, even after years of dust exposure.
Corrosion Resistance for Aggressive Atmospheres
Epoxy resin is inherently resistant to a broad range of chemicals. For chemical processing plants, electroplating facilities or coastal installations with salt mist, we provide additional protective coatings, stainless steel hardware and a durable paint finish validated under salt spray tests. This multi layer protection ensures structural integrity and electrical reliability in corrosive environments.
5. Frequently Asked Questions
Q1: How does this transformer handle continuous operation in an environment with 95% humidity and 40°C ambient temperature, conditions typical of Southeast Asia?
The vacuum cast epoxy winding is impervious to moisture and has been tested under damp heat cycling per IEC 60068. With adequate enclosure ventilation and optional anti condensation heaters, the transformer can be started and operated safely without preheating, even when condensation forms on external surfaces overnight.
Q2: Will conductive dust from our cement or textile plant cause insulation failure over time?
No. The solid insulation surface prevents dust penetration into winding layers. When paired with an IP4X or IP54 enclosure, dust is limited to exterior surfaces only. Because there are no exposed bare conductors, the risk of conductive tracking is virtually eliminated, ensuring long term reliability even in heavily contaminated air.
Q3: Can this transformer deliver full 630kVA at 50°C ambient temperature without forced cooling?
Yes. The unit is designed for continuous rated power with natural air cooling (AN) at up to 50°C ambient, thanks to its Class H insulation and F class temperature rise reserve. For periodic overloads or higher ambient extremes, forced air cooling can be added, typically increasing capacity by 20 to 40 percent.
Q4: What kind of maintenance is required when operating in a hot and dusty industrial environment?
Maintenance is minimal. We recommend an annual visual inspection, cleaning of winding surfaces with a vacuum cleaner, and checking connection torque. There is no oil to test, no gaskets to replace, and the cast coils require no reconditioning, resulting in decades of near maintenance free operation.
Q5: We are an EPC company and need the transformer to meet local utility (PLN) approval. Can you customize it?
Absolutely. We routinely supply transformers with specific voltage ratios, vector groups, enclosure ratings and documentation packages to satisfy PLN, SNI or other national standards. We provide full type test certificates, outline drawings and remote commissioning support to streamline project acceptance.
Q6: What makes this dry type transformer more suitable for a chemical plant than an oil filled unit?
The absence of flammable insulating oil removes the risk of fire propagation and eliminates the need for oil containment bunds. Epoxy resin is self extinguishing. The transformer can be installed indoors, right next to process equipment, saving space and simplifying civil works while meeting strict fire safety codes.
6. Call to Action
Request your custom transformer solution today and our engineers will design to your exact tropical and industrial specifications.
