... magnetic Insulation Class B Consolidate construction Adopted IEC standard This series alternators are to be used in town, countryside, worksites, mountain ... oC ~ 40 oC) Relative air damping: not exceed 90% This series alternators are to be used in town, countryside, worksites, mountain ... and adopt harmonic excitation system, easy operation and maintenance. STC Three-Phase A.C, Synchronous Alternators