DO-160-Section-16-Power-Input

RTCA DO-160 Section 16.0 Power Input Testing

The RTCA DO-160 power inputs test defines the test conditions and procedures for ac and dc electrical power applied to the terminals of equipment to be tested. RTCA-DO-160 power testing covers the following electrical power supplies:

  • 14 V dc, 28 V dc and 270 V dc
  • 115 Vrms ac and 230 Vrms ac at either a nominal 400 Hz frequency or over a variable frequency range which includes 400 Hz.

The standard states that equipment categories and frequency classes, test conditions and procedures for equipment using other electrical power supplies must be defined in applicable equipment performance standards.

Equipment Categories of RTCA DO-160G Section 16 Power Input

Categories A(CF), A(NF), A(WF) and A are all equipment intended for use on aircraft electrical systems where the primary power is from a constant or variable frequency ac system and where the dc system is supplied from transformer-rectifier units. For ac equipment, Categories A(CF), A(NF) or A(WF) apply. For dc equipment, Category A applies.

  • Category A(CF) designates ac equipment intended for use on aircraft electrical systems where the primary power is from constant frequency (400 Hz) ac system. A(CF) designates the same equipment as the ac ones designated by Category A in DO-160 / ED14 issues A to D.
  • Category A(NF) designates ac equipment intended for use on aircraft electrical systems where the primary power is from narrow variable frequency (360 to 650 Hz) ac system.
  • Category A(WF) designates ac equipment intended for use on aircraft electrical systems where the primary power is from wide variable frequency (360 to 800 Hz) ac system.
  • Category “A” designates 28 V dc equipment intended for use on aircraft electrical systems where the dc is generated from primary power supplied from either a constant or variable frequency ac system. Category A dc equipment may have a battery floating on the dc bus.

Category B is for 14 V or 28 V dc equipment intended for use on aircraft electrical systems supplied by engine-driven alternator/rectifiers, or dc generators where a battery of significant capacity is floating on the dc bus at all times.

Category D is for 270 V dc equipment intended for use on aircraft electrical systems where the dc is generated from primary power supplied from either a constant or variable frequency ac system.

Category Z is for 28 V dc equipment that may be used on all other types of aircraft electrical systems applicable to these standards is identified as Category Z. Category Z shall be acceptable for use in lieu of Category A or Category B. Examples of this category are dc systems supplied from variable speed generators where:

  • The dc supply does not have a battery floating on the dc bus, or
  • The control or protective equipment may disconnect the battery from the dc bus, or
  • The battery capacity is small compared with the capacity of the dc generators.

RTCA/DO-160 Power Input Test Lab Test Designations

AC Distortion Tests: Designation H

This power input test equipment designation relates to ac equipment with an individual maximum power consumption greater than 35 VA or installations where the combined power consumption of multiple units, of the same equipment type, is greater than 150 VA. For such equipment, the current distortion tests have to be performed if required by the equipment performance standards.

AC Current Modulation Control Tests: Designation L

This DO-160G EMC test equipment designation relates to ac equipment where the current ripple (or current modulation) drawn from the EUT is controlled. AC powered equipment that meets the requirements of this test designation is to be marked with test designation L. Equipment that does not meet the requirements of designation L is to still be tested (report levels only) and is marked with test designation Z.

AC Power Factor Tests: Designation P:

This RTCA-DO-160G power input test designation relates to ac equipment where the power factor of the ac power drawn by the EUT is controlled. AC powered equipment that meets the requirements of this test designation is to be marked with test designation P. Equipment that does not meet the requirements of designation P is to still be tested and is marked with test designation Z. Test designation Z is considered other test criterion.

DC current ripple tests: Designation R:

This test designation relates to dc powered equipment with an individual maximum power consumption level. That level is greater than 400 W for 28V or 35 W for 270V or installations where the combined power consumption of multiple units is greater than 400 W for 28V or 150 W for 270V. The multiple units all have to be the same equipment type. For such equipment, the DC current ripple tests have to be performed. This is only required if specified by the equipment performance standards.

AC or DC Inrush Current tests: Designation I:

This DO-160G power input EMC test equipment designation is assigned to ac or dc equipment that meets the inrush current requirements specified for designation I. For such equipment, the inrush current tests of section 16.7.5 have to be performed if required by the equipment performance standards.

Keystone Compliance is a leading EMC test lab in the country. With seven EMC test chambers a substantial amount of test equipment, we are able to offer shot lead times on scheduling. Our lab is 17025 accredited to RTCADO-160 testing. In addition to providing RTCA-DO-160G testing, Keystone is accredited to all previous versions of this military test standard as well.

Our EMC-EMI test lab can accommodate small and large items. Please contact us to see firsthand why so many manufacturers rely on Keystone Compliance to be their RTCA DO-160 test lab.

Looking for other testing to other sections of RTCA DO-160 testing? Click on the links below:

Modifications from one Version of RTCA DO-160 to the Next:

Changes from DO-160C Power Input Testing to DO-160D Power Input Testing

Change 2 to DO-160D, published June 12, 2001, revised Section 16, by including new tests, and modifications to existing testing, to address the issues of AC harmonic current content and variable frequency AC power systems.

Changes from DO-160D Power Input Testing to DO-160E Power Input Testing

The entire section was re-ordered so that all the AC tests were in one subsection and all DC tests were in another subsection, making Section 16 easier to use and understand. DO-160E also introduced some new tests, such as a DC content test for AC powered equipment, and a new subsection covering “Load Equipment Influence on Aircraft Electrical Power Systems.”

Changes from DO-160E Power Input Testing to DO-160F Power Input Testing

More tests are required for both AC and DC powered equipment. A 270V DC bus generated from the A (WF) AC power bus was added as Category D.  Discrete step test methods were defined for AM and FM modulation on AC systems. AM voltage modulation on AC buses was increased. Double interrupt test methods were added for DC equipment.  Manual reset was explicitly not permitted after single and double power interrupts.  The dwell at 28V between the short and the long dc voltage surge was removed. Loss of phase testing was added for three phase. A Power Factor test designation was added for ac equipment. DC current draw tests from AC equipment current were added. In-rush and current modulation test designations were added for both AC and DC equipment. Tolerances were added to most tests. Category H, harmonic emissions, measurement methods were updated.

Changes from DO-160F Power Input Testing to DO-160G Power Input Testing

Added alternate test “”Z”” for ac inrush tests.  Clarified peak current definition in inrush testing. Allow performance of emergency limits for Category A(CF) equipment to constitute performance of normal (part c. (1)) test conditions.  Allow performance of emergency limits to constitute performance of normal (part b. (2)) test conditions.  Added equipment with analog circuitry to be tested with the test conditions of Table 16-1 and Table 16-3.