CastBlock® Transformers

The EpoxyBlock® transformers we offer at AFP Transformers provide several advantages to traditional dry type transformers. Instead of using vacuum pressure impregnation to apply resin to all the transformer coils, both the primary and secondary coils are directly cast in a mold under a vacuum. As a result, the coils are completely embedded in an epoxy material. This protects coils from contaminates and holds the windings in place during power surges. This makes them a good choice for difficult environments such as chemical plants, oil refineries, water treatment, and mine duty applications.

The tough epoxy material is essentially maintenance free and since EpoxyBlock® is still considered a dry type transformer, there are no hazardous liquids to pose a safety or environmental risk. Since they do not contain hazardous materials, EpoxyBlock® transformers do not require transformer vaults or a liquid containment area that limit placement options and significantly add to the cost of liquid filled transformers.

We manufacture a wide range of EpoxyBlock® transformers from 600V to 5 kV voltage classes. Some of the most common applications for EpoxyBlock® transformers include control power transformers, pad-mount distribution transformers, and neutral grounding transformers used in utility and cubicle applications.

For additional information about our line of standard and custom EpoxyBlock® transformers, see the table below, or Contact Us directly.

CastBlock® Transformers Capabilities

Transformer Type
Control Power Transformers
Neutral Grounding Transformers
Distribution Transformers
Power Transformers
ZigZag Transformers
Superior Short Circuit Resistance
Low/No Maintenance Required
Leak Proof
No Hazardous Materials
Power Type
Single Phase
Three Phase
Voltage Class
600 V
5 kV
Cast Coil (EpoxyBlock®)
Winding Material
Copper Wire Standard
Additional Configurations on Request
BIL Rating
60kV to 95kV
Dependent on Transformer Voltage Rating or customer requirements
100% Product Testing
IEEE C57.12.91 Special, Standard, or Custom
Testing Parameters Stored
  • Voltage
  • Current
  • Watts
  • Vars
  • VA
  • Power Factor
  • Efficiency
Customer Specified Testing as Requested
Stocking Programs
JIT Shipping
Production Volume
Low Volume
High Volume
Lead Time
3 to 6 Weeks Typical
Expedited Turnaround in as little as 1.5 Week

Additional Information

Industry Focus & Applications
Switchgear Manufacturers
Motor Control Center Manufacturers
Power Factor Correcting Equipment Manufacturers
Power Conditioning Equipment Manufacturers
  • PDU manufacturers
  • UPS manufacturers
  • Voltage Regulator Manufacturers
  • Data Center CPUs
Industrial Heating Equipment Manufacturers
  • Furnaces
  • Induction Heating Power Supplies
  • RF and Microwave Heating Machines
Mining Machine Manufacturers
Waste Water Treatment
Chemical Plants
OEM Machine Manufacturers
  • Machine Toolmakers
  • Packaging Machines
  • Semiconductor Machine Manufacturers
  • Web Processing Machine Manufacturers
Industry Standards
IEEE C57.12.01
General Requirements for Dry-Type Distribution & Power Transformers, Including Solid Cast
IEEE C57.12.91
Standard Test Code for Dry-Type Distribution & Power Transformers
UL 508
UL Standard for Industrial Control Equipment
UL 506
UL Standard for Specialty Transformers
UL 1561
Industry Standard for Dry Type General Purpose & Power Transformers, 600 Volt Class
UL 1562
Industry Standard for Dry Type General Purpose & Power Transformers, Medium Voltage, Up to 34.5 KV
Standard for Dry Type Transformers for General Applications
Test Code for Transformers, Regulators & Reactors
Industrial Standard for Controllers, Contactors, Overload Relays & Related Equipment. (Motor Starting Autotransformers & Reactors)
International Standards
IEC 60076
Power Transformer & Reactors - Medium Voltage
IEC 61558
Power Transformers & Reactors - 600 Volt Class
CE Certification to IEC Standards
Marine Standards
American Bureau of Ships
Det Norske Veritas