MIL-STD-704 Aircraft Electrical Power Specifications Standard, prepared by the United States (US) Department of Defense, is a military standard that covers issues such as voltage, frequency, phase, fluctuation and maximum current in a military aircraft and its equipment. The most current version of the standard is MIL-STD-704F_CHG-1, published in 2016. However, this standard is not a standard that only covers the US military and its subcontractors, but is a globally accepted standard for evaluating the suitability of military aircraft and systems. It is converted to the voltage levels required for the operation of the equipment used in the aircraft power system, which comes with a power source that complies with the MIL-STD-704 standard. In order for a piece of equipment to operate in accordance with the MIL-STD-704 standard, it must pass MIL-STD-704 tests to see its effects under difficult conditions and to verify its conformity.

The LDC401 Voltage Steady State Limits Test is performed to verify that 28V DC power handling equipment operates within the Emergency Low Steady State (ELSS) limits and Emergency High Steady State (EHSS) limits and maintains specified performance. The equipment used in the LDC401 Voltage Steady State Limits Test must not be damaged or cause an unsafe condition. This test takes a minimum of 30 minutes.

In the LDC401 Voltage Steady State Limits Test, the usage equipment is passed MIL if the applicable version(s) operates and maintains performance as specified in the usage equipment performance specification document for emergency aircraft electrical conditions when input power voltage is supplied at the specified emergency steady state limits. -STD-704 and accepted as stated in the table.

LDC401 Voltage Steady State Limits Test use equipment must maintain specified performance for a period of time verifying that the use equipment can operate continuously at steady state voltage and shall not be less than thirty (30) minutes for each of the test conditions.

Unless otherwise specified in the LDC401 Voltage Steady State Limits Test usage equipment performance specification document, usage equipment must demonstrate restart at emergency steady state voltage limits. Unless otherwise specified in the operating equipment performance specification document, when power returns to normal limits, utilization should automatically return to the performance specified for normal aircraft electrical conditions. Operating equipment must not be damaged or cause an unsafe situation.