Federal Pacific ventilated dry-type transformers incorporate wire and/or strip wound coils in a barrel wound configuration. Horizontal and vertical spacers are strategically positioned in the windings to brace the winding layers and allow maximum ventilation. The electrical grade core steel is arranged in a construction designed to accommodate the coils. The insulation system has received a 220°C continuous rating from Underwriters Laboratories, Inc. derived from the average conductor temperature rise of 150°C, hotspot temperature gradient of 30°C, and a maximum ambient temperature of 40°C.
Ratings in the 600V class are available from .050 through 333 KVA in single-phase configurations and from 3 through 1500 KVA in three-phase. All standard primary and secondary voltage ratings are provided to match load requirements to the distribution system.
The air-cooled dry-type construction requires no special vaults for installation. The units may be located in almost any indoor location convenient to the load being served. Most transformers are also available for outdoor installations. Maintenance requires only periodic inspection of cable connections and removal of any dust accumulation.
All Federal Pacific three-phase transformers and most single-phase models are provided with taps in the primary winding to compensate for input voltage variations. The taps will provide a range of voltage adjustment above and/or below the nominal voltage rating of the transformer. The available quantity, location, and percentage of the tap connections are shown in the transformer specifications. All transformers are furnished with a nameplate showing the terminal and tap arrangements.