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-1399-3008

f.     Three (for 3-phase) or two (for single phase) 100,000 ohm, 450 Vrms, 5W resistors.

g.    Three (for 3-phase) or two (for single phase) single-pole fused switches or circuit breaker sized for the short circuit rating of the power supply.

5.3.5.2  Procedure.  It is recommended that an isolated power source be used for this test to prevent grounding of commercial utility power lines.  Each power input line shall be grounded through a 100,000-ohm resistor to the ground plane.  The user equipment enclosure shall be grounded to the same ground plane.  Each 100,000-ohm resistor shall have in parallel a single pole fused switch or circuit breaker of adequate rating.  With the equipment operating in a normal operating mode and with voltage and frequency within the user tolerance envelope, close a switch and short one of the 100,000-ohm resistors.  Leave the ground condition on for a sufficient period to determine any user equipment degradation, but at least for a minimum of 5 minutes, then remove the ground by opening the switch.  Ground each power line in turn in the same manner.  Repeat the test for each operating mode. Recordings of each input voltage shall be made for each test.  The user equipment shall sustain normal operation throughout the grounding test.

5.3.6  User equipment power profile test.  User equipment shall be tested to determine the following items in all operating modes.  If the user equipment requires more than one input from the electric power system, the data shall be provided for each power input required.  The power profile data shall include the applicable data listed below for each operating mode and shall be in accordance with the associated procedure.

a.    Type of power (per 5.2.2).

b.    Number of phases (per 5.2.2). c.    Voltage (rms) (per 5.2.2).

d.    Line current magnitudes (rms).

e.    Power factor (leading or lagging) (per 5.2.6).

f.        Power kilowatt (kW) rated and typical operating power profile (per 5.2.2). g.    Surge/inrush current (per 5.2.10) - peak magnitude and duration.

h.    Pulsed loading (per 5.2.7).

i.     Load unbalance (per 5.2.5). J.     Spike generation.

k.    Submarine Rigged for Reduced Electric (RRE) configuration power demand, where applicable. l.     Line-to-ground capacitance

m.   Line-to-ground current

5.3.6.1  Apparatus.  The following apparatus is recommended for performing this test:

a.    Power source of required capacity and range of voltage and frequency adJustments.  A power source with a capability of having an independently programmable voltage and frequency output is recommended.

b.    Voltmeters (true rms) - ±0.5 percent accuracy. c.    Frequency meter - ±0.5 Hz accuracy.

d.    Ammeters.

e.    Power factor meter.

f.        Storage oscilloscope having � 500 kHz response per channel. g.    Current and potential transformers and probes as required.

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