MIL-T-15108C, MILITARY SPECIFICATION: TRANSFORMERS, POWER, STEP DOWN, SINGLE PHASE, 60 HERTZ, 1 KILOVOLTAMPERE APPROXIMATE MINIMUM RATING, DRY TYPE, NAVAL SHIPBOARD (20 NOV 1975)., This specification covers dry type, 60-hertz (Hz), single-phase, electric transformers of standard mounting dimensions for shipboard use.