This specification establishes the performance requirements for surge suppressors used on shipboard ac power circuits that may consist of a single circuit element or may be a hybrid device using several suppression devices. The surge suppressor shall be a protective device for limiting voltage transients on equipment by discharging, dissipating internally, bypassing surge current, or a combination thereof, and which prevents continued flow of follow current to ground and is capable of repeating these functions. Surge suppressors shall be classified into the following classes and types: Class A-surge suppressor associated with long circuit branch; Class B-surge suppressor for short branch circuit; and Type I-permanent connected type; Type II-plug-in type; Type III-cord-connected type; and Type IV-power director (power center) type. The surge suppressors shall conform to specified performance, operating, grounding, and supplementary protection requirements. They shall also undergo designated design, and conformance production tests such as insulation withstand test, power frequency withstand test, impulse voltage-time tests (including fast-front impulse suppression tests and slow-front impulse suppression tests), voltage protection level tests, duty cycle tests, life cycle tests (including voltage and current impulses), load current and voltage drop tests (including rated current and voltage drop and inrush current), and ground continuity test.