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MIL-STD-1399 Testing

MIL-STD 1399 is a military standard approved for use by the Naval Sea Systems Command, Department of the Navy, and is available for use by all Departments and Agencies of the Department of Defense. The purpose of MIL STD 1399 is to define the standard interface requirements and constraints applicable on the design of shipboard user equipment that will utilize shipboard alternating current (at) electric power.

MIL-STD-1399 lists the Nature of the Interface as follows:

In any system involving power source, distribution network, and load (user equipment), the characteristics at the system and user equipment interface are mutually dependent upon the design and operation of both. In order for the electric power system to perform within the established tolerances, it is necessary to place constraints on the power source, the distribution system and the user equipment. This interface standard defines the electric power system characteristics. User equipment constraints are also established.

MIL-STD-1399 lists the Structure as follows:

The technical content first delineates the characteristics of the shipboard electric power system at the interface in terms of voltage, frequency, continuity, and voltage waveform. Constraints on user equipment design and installation which are necessary to achieve shipboard compatibility with and to assure these characteristics are then established. Finally, test requirements are specified to verify conformance to this standard.

MIL-STD-1399 lists the Structure as follows:

This section establishes electrical interface characteristics for shipboard equipment utilizing AC electric power to ensure compatibility between user equipment and the electric power system. Characteristics of the electric power system are defined and tolerances are established. User equipment shall operate from a power system having these characteristics and shall be designed within these constraints in order to reduce adverse effects of the user equipment on the electric power system. Test methods are included for verification of compatibility.

MIL-STD-1399 specifies the types of shipboard electric power to be supplied from the electric power system are as follows:

Type I: Type I power is 440 or 115 volts (V), 60 hertz (Hz) ungrounded and is the standard shipboard electric power source. Type I power shall be used unless a deviation is granted (see 4.3).
Type II: Type II power is 440 or 115 V, 400 Hz ungrounded and has only limited application. Use of type II power requires the submittal and approval of a deviation request (see 4.3).
Type III: Type III power is 440 or 115 V, 400 Hz ungrounded having tighter tolerances as compared to types I and II. Type III power has restricted use and its use requires submittal and approval of a deviation request (see 4.3).

MIL-STD-1399 also specifies a special power classification for types of shipboard electric power supplied only for avionic shops and aircraft servicing. The specific power classifications are as follows:

Type I: Type I power is 115/200 V, 60 Hz, 3 phase, 4 wire, Wye grounded. This power is only provided for avionic shops.
Type III: Type III power is 115/200 V, 400 Hz, 3 phase, 4 wire, Wye grounded. This power is only provided for avionic shops and for aircraft servicing.

MIL-STD-1399 is revised periodically. The existing versions of the standard include MIL-STD-1399 C, MIL-STD 1399 B and MIL-STD 1399 A.

Keystone Compliance assists manufacturers with MIL-STD-1399 compliance. This page lists every method and section of the standard for informational purposes. There may be methods and sections that fall outside of our scope. Please contact us for more information on how Keystone Compliance can assist you with identifying and fulfilling your MIL-STD-1399 needs.