Primary CurrentOvercurrent Protection Rating Primary CurrentOvercurrent Protection Rating Less than 2 amps 300% maximum2 to 9 amps 167% maximum9 amps or more 125% of rated primary current (or next highest standard rating) Less than 2 amps300% maximum2 to 9 amps167% maximum9 amps or more125% of rated primary current (or next highest standard rating) Diagram A Diagram B > Primary CurrentSecondary CurrentOvercurrentProtection Rating 250% primary currentLess than 9 amps 167% maximumNot more than 250%9 amps or more 125% (or next higher standard rating) Primary CurrentSecondary CurrentOvercurrentProtection Rating Diagram C 250% primary currentLess than 9 amps 167% maximumNot more than 250%9 amps or more 125% (or next higher standard rating) > Diagram D * Reprinted with permission from NFPA 70-2005, National Electri-cal Code > , Ω2008, National Fire Protection As sociation, Quincy, MA 02269. This reprinted material is not the com plete and of cial position of the NFPA on the ref er enced subject which is represented only by the standard in its entirety. >

Applications Any situation where the available voltage must be changed to accommodate the voltage required by the speci c electrical circuit or connected equipment. For many electrical circuits, the National Electrical Code (NEC) requires a separately derived neutral secondary connection provided by Delta-Wye connected transformers.Distribution transformers can be located close to the load. No vaults are required for installation and no long, ex pensivefeeder lines are needed. Common ap plications include inductive and re sistive loads such as motors, lighting and heating. General Purpose Transformers...