Electrical and electronic equipment is designed to operate on a standard supply voltage. In certain environments the source power may not be at the standard rating for a variety of reasons. When there is variation in the standard supply voltage a Buck-Boost transformer can be used as a simple and economical means of correcting deviations up to ± 20%. When the supply voltage is constantly too high or too low, (usually greater than ± 5%), the equipment may fail to operate at maximum efficiency.
A Buck-Boost Transformer has four separate windings, two windings in the primary and two windings in the secondary. The unit is designed for use as an isolating transformer or as an auto-transformer. As an autotransformer the unit can be connected to Buck (decrease) or Boost (increase) a supply voltage.
Autotransformers are more economical and physically smaller than equivalent two-winding transformers designed to carry the same load. They will perform the same function as two-winding transformers with the exception of isolating two circuits. Since autotransformers may transmit line disturbances directly, they may be prohibited in some areas by local building codes, before applying them, consult local codes.
A Buck-Boost transformer will NOT stabilize a fluctuating voltage.
An encapsulated dry-type transformer is a totally enclosed, compound filled transformer. The core and coil assembly is embedded in a polyester resin compound, which provides solid insulation. The embedding compound has an extremely high heat transfer rate, which permits a design of minimum size and weight. The compound-filled assembly is completely encased in a sturdy steel housing and cannot be damaged by dust, moisture, or adverse atmospheric conditions.
Federal Pacific UL & CUL Listed encapsulated dry-type transformers can be used in industrial, commercial, institutional, and residential installations for economical, efficient distribution of power. Encapsulated units are ideal for dusty industrial areas and are suitable for Indoor and Outdoor applications. Typical loads served include tanning beds, motors, lighting, heating, ranges, air conditioners, exhaust fans, control circuits, appliances, and portable tools.
Federal Pacific encapsulated transformers are designed based on a 25°C ambient, 115°C rise, 180°C insulation system. Due to low enclosure temperature rise, no UL-506 special markings are needed to indicate clearance between the enclosure and adjacent surfaces. Sound level problems are negligible with encapsulated transformers because the core and coils are rigidly encased in the polyester resin, which is mechanically strong and acts as sound deadening material.