Heavy-Duty Vacuum Cast Coil Transformer Technology
At AFP Transformers Corp., our proprietary Castblock® (EpoxyBlock®) dry-type transformers deliver unmatched operational reliability compared to conventional vacuum pressure impregnated (VPI) units. By casting both primary and secondary windings directly inside dedicated molds under deep vacuum, the coils become entirely encapsulated in a solid epoxy matrix.
This seamless epoxy structure locks electrical windings in place to withstand extreme mechanical short-circuit forces while completely isolating conductors from moisture, airborne contaminants, and corrosive chemicals. Engineered for severe industrial environments—including chemical plants, oil refineries, wastewater treatment facilities, and underground mining operations—our Castblock® technology ensures maximum uptime with zero routine liquid maintenance.
Contaminant & Moisture Proof
Solid epoxy encapsulation creates a hermetic barrier against moisture, salt spray, chemical fumes, and conductive dusts.
Short-Circuit Resilient
Rigid cast coil construction provides supreme mechanical strength, preventing winding displacement during high electrical surges.
Zero Environmental Hazards
Fluid-free dry type design eliminates fire hazards and toxic oil spill risks—no concrete containment vaults or special fire suppression required.
Precision-Engineered Castblock® Assemblies
CastBlock® Transformer Technical Capabilities
- Control Power Transformers
- Neutral Grounding Transformers
- Pad-Mount Distribution Transformers
- Industrial Power Transformers
- ZigZag Grounding & Phase-Shifting Transformers
- Non-Flammable & Flame-Retardant Epoxy Resin
- Superior Mechanical Short Circuit Resistance
- Virtually Maintenance-Free Operation
- Leak-Proof & Sealed Against Moisture/Contaminants
- Free of Hazardous PCB & Mineral Oils
- Single Phase (1-Phase)
- Three Phase (3-Phase)
- 600V Class
- 5 kV Class
- High-Conductivity Copper Wire Standard
- Aluminum Windings & Custom Lead Configurations Available
100% Routine In-House Inspection & Test Parameters Logged:
- Full IEEE C57.12.91 Testing Suite (Voltage, Current, Watts, Vars, VA, Power Factor, Efficiency)
- Applied Potential (HiPot) Testing up to 100 kV AC RMS
- Basic Impulse Level (BIL) Capability testing up to 300 kV
- Partial Discharge (PD) Testing: Up to 100 kV applied / >70 kV induced potential
- KanBan Reserve Stocking Programs
- Just-In-Time (JIT) Scheduled Deliveries
- Vendor-Managed Min-Max Inventory Management
- Prototype, Low-Volume, and Mass OEM Production Runs
- Standard Production: 3 to 6 Weeks
- Expedited OEM Turnaround: As fast as 1.5 Weeks
Industrial Applications & Compliance Standards
- Switchgear & Motor Control Centers: OEM drive isolation and control power supply
- Power Conditioning & Data Infrastructure: PDU, UPS units, Voltage Regulators
- Industrial Thermal Systems: Electric furnaces, induction heating power supplies, RF/microwave equipment
- Heavy Industrial Duty: Underground mining machinery, wastewater treatment, chemical processing
- OEM Machinery Builders: Semiconductor tools, CNC machine toolmakers, web processing lines
IEEE & NEMA Compliance: IEEE C57.12.01, IEEE C57.12.91, NEMA ST 20, NEMA TR1, NEMA ICS 2
UL Certification Standards: UL 506, UL 508, UL 1561 (600V Class), UL 1562 (Medium Voltage up to 34.5kV)
Global & Marine Certifications: IEC 60076, IEC 61558, CE Mark, American Bureau of Shipping (ABS), Det Norske Veritas (DNV)
Need a Custom Castblock® Transformer Solution?
Our engineering experts design custom cast coil transformers tailored precisely to your application specifications, dimensional constraints, and delivery schedules.