MIL-STD-1399-300 Electric Power, Alternating CurrentThis military standard 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, as well as requirements and test methods for ensuring compatibility of shipboard user equipment with the power system. The policies and procedures established by MIL-STD-1399 are mandatory. This section and the basic standard are to be viewed as an integral single document for use in the design and testing of electric power systems and user equipment.

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MIL-STD-1399-300B

5.3.3.2  Procedure.  Figures 23, 24, and 25 show the single-phase 115 Vrms, three-phase 115 Vrms, and three- phase 440 Vrms voltage spike test circuit configuration diagrams, respectively, for Type I power.  Figures 26 and 27 show the voltage spike test circuit configuration diagrams for Types II and III power.  For voltage spike calibration purposes, the user equipment shall be disconnected from the power source and the voltage spike waveform shown in Figure 6 shall be superimposed on the power source voltage.  A one-ohm damping impedance shall be utilized in series with the high-voltage output line of the voltage spike generator.  The voltage spike shall be calibrated between each power line to ground with the UUT disconnected, for the four synchronization positions shown in Tables IV

and V.  The voltage spike waveform shown in Figure 6 can be achieved between any two power lines or from the power line under test to ground.  The voltage spike exhibited during open-circuit calibration shall have a peak value (including the fundamental AC waveform voltage) of 2,400 to 2,500 V peak for 440 Vrms system and 900 to 1,000

V peak for 115 Vrms systems.  After establishing the open-circuit calibrated voltage spike, the user equipment shall

be reconnected and five positive polarity voltage spikes at the rate of two per minute shall be applied at 0 degrees and five positive polarity voltage spikes at the rate of two per minute shall be applied at 90 degrees.  Then, after reversing the "high voltage out" and "common" connections, five negative polarity voltage spikes at the rate of two per minute shall be applied at 0 degrees and five negative polarity voltage spikes at the rate of two per minute shall be applied at 270 degrees.  The test shall be repeated for each line to ground; reconfigure the test circuit (the capacitor and, if required, parallel inductor to ground shall not be connected to the line having the spike applied, but to the remaining line or lines).  The voltage spike test conditions are described in Table IV for single-phase systems and in Table V for three-phase systems.  Respective line-to-ground voltage, line-to-line voltage, and spike current parameter data shall be monitored and recorded to ensure proper testing.  Equipment shall remain operational

before, during, and after each applied voltage spike.  The UUT shall not experience any operational interruption, suffer any loss of data, or require a restart or reboot.

TABLE IV.  Single-phase system voltage spike test conditions.

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