Schaffner Magne-Seal


Providing the solution for premium-duty sealed transformer needs

Schaffner’s exclusive Magne-Seal design provides the solution for premium-duty sealed transformer needs in heavy commercial and industrial applications. It combines the environmentally friendly, cost-effective, flexible design benefits of dry-type transformers and the protection capabilities of cast coil and liquid-filled transformers.

The product

Magne-Seal begins in the coil winding process using special techniques to install materials that create a seal at the bottom of each winding layer. Coils are then pre-baked to thoroughly dry them for varnish processing. During a two-step vacuum pressure impregnation (VPI) process, every layer of conductor and insulation material is filled with varnish like a column. After baking the coils to cure the VPI process, a final high-build polyester varnish finish is applied.

The finished Magne-Seal product provides coils that are completely sealed against the environment. All Magne-Seal materials – Nomex insulation, polyester varnish, sealing materials – are fully rated for a 220º C insulation system.

Environmental Advantages

1. No Fluid Containment Required – Magne-Seal is a dry transformer and contains no fluids. It doesn’t require expensive basins to contain potential spills and eliminates the concern of transformer fluids escaping containment barriers.

2. Fire Resistant – MagneSeal has successfully passed fire testing that verifies the materials used to construct it do not support combustion.
No explosion barriers or blast containment are required.

Design Advantages

1. Higher Overload Capability – All the materials used in the Magne-Seal insulation system are fully rated for 220º C. Epoxy materials used in cast coil and other designs are rated for much lower temperatures. Magne-Seal is able to deliver 15-30% more overload capacity than designs that use epoxy materials.

2. Smaller Footprint – The Magne-Seal processing system doesn’t restrict the use of coil cooling ducts. This allows MTC designers to provide an efficient convection cooling system that requires less floor space. Magne-Seal footprints are typically 10-20% smaller than cast coil footprints.

3. Flexibility – Since Magne-Seal isn’t cast in a mold, designs aren’t restricted by mold sizes. Schaffner designers have available a full range of coil geometries and winding configurations to provide electrical parameters and physical dimensions exactly as specified.

4. Cost Effective – No molds, expensive casting equipment, or epoxy insulation are required. Magne-Seal provides a sealed coil transformer efficiently and effectively. An experienced Schaffner sales staff is available to show you the cost advantage.