Power Input

RTCA DO-160 – Section 16.0 – Power Input

 

This section defines test conditions and procedures for ac and dc electrical power applied to the terminals of the equipment under test.
It 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
Equipment categories and frequency classes, test conditions and procedures for equipment using other electrical power supplies must be defined in applicable equipment performance standards.

 

Categories A(CF), A(NF), A(WF) and A: 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, is identified as:
  • for ac equipment: Category A(CF), A(NF) or A(WF)
  • for dc equipment: Category A
– 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(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.
– 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.
– “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: 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, is identified as Category B.

 

Category D: 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, is identified as Category D.

 

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

 

Sect16-700