California Instruments Tahoe | TA0045A1 Power Supply | 45 kVA

RTCA/DO-160 Section 16 test procedures are used to determine whether the EUT can operate during different AC and/or DC power variations that occur during normal and emergency aircraft operation. RTCA/DO-160 Section 16 tests verify whether the equipment will negatively affect the aircraft power system that would be harmful or degrade performance in other equipment. These tests cover both susceptibility (surge, dropout, frequency transients, etc.) and harmful interference (current harmonics, re-generated energy, power factor, etc.) of the EUT.   Tests: DC Input tests Steady-state over- and under-voltage conditions Ripple voltage Momentary power interruption Momentary sags and surges Exposed voltage decay time (270 V only) Inrush current AC Input tests Steady-state over- and under-voltage conditions Steady-state over- and under-frequency conditions Steady-state phase unbalance (three-phase power) Voltage and frequency modulation Voltage and frequency transients Momentary power interruption Momentary sags and surges DC offset and voltage distortion Harmonic current emissions Phase unbalance (3 phase inputs) DC current content Inrush current Current modulation Power factor Equipment Categories According to RTCA/DO-160 Section 16, there are four Equipment Categories (A, B, D, or Z) that indicate the type of power used by the equipment and the type of AC and/or DC power source with which the equipment is compatible. For AC powered equipment, an additional designator, placed in parenthesis following the Category designator, is a two-character code indicating that the equipment has been tested for use with Constant Frequency (CF), Narrow Variable Frequency (NF), or Wide Variable Frequency (WF). Up to four additional category designators are also used to indicate testing for: AC current harmonics (H) AC current modulation (L) AC power factor (P) DC current ripple (R) AC or DC inrush

MIL-STD-704 defines the requirements outlined by the Department of Defense for the characteristics of aircraft electric power generated at the input terminals of electric utilization equipment. MIL-STD-704 is intended to detail electric power quality requirements for DoD aircraft, but may also be used with commercial planes or other vehicle types. Standards like ISO 1540 and SAE-AS1212 also dictate aircraft electric power requirements, but are not generally relevant for military aircraft, as they do not address the areas of concern for military aircraft electric power quality and need wider limits compared to MIL-STD-704. MIL-STD-704 also takes into account legacy DoD equipment and aircraft electrical systems.   General Requirements 4.1 Aircraft Electric Power System Requirements   Aircraft electrical power systems should offer electric power with the characteristics specified in this standard at the utilization equipment terminals during all powerations of the power system. Airframe manufacturers or modifiers are responsible for offering the distribution and protection network to the terminals of the utilization equipment while maintaining power characteristics specified in MIL-STD-704; characteristics of the power measured at the output terminal of an unregulated power source or the POR of a regulated power source should be within the limits specified in the detail specification applicable to the power source. Protective devices should operate independently of control/regulation equipment. 4.2 Aircraft Utilization Equipment Requirements   Utilization equipment should be compatible with the power characteristics specified in MIL-STD-704. Aircraft should operate at the performance level specified in its detail specification in all of the following modes of operation: Normal Abnormal Transfer Emergency Starting Loss of power or the loss of one or more phases of AC should not result in

IEC 61000-3-11 is concerned with the emission of voltage changes, voltage fluctuations and flicker produced by equipment and impressed on the public low-voltage supply system. IEC 61000-3-11 specifies the limits of voltage changes produced by equipment tested under specified conditions. IEC 61000-3-11 is primarily applicable to electrical and electronic equipment having a rated input current from 16 A up to and including 75 A, which is intended to be connected to public low-voltage distribution systems having nominal system voltages of between 220 V and 250 V, line-to-neutral at 50 Hz, and which is subject to conditional connection. This part of IEC 61000 is also applicable to equipment within the scope of IEC 61000-3-3 that does not meet the limits when tested or evaluated with reference impedance Zref and is therefore subject to conditional connection. Equipment that meets the requirements of IEC 61000-3-3, is excluded from this part of IEC 61000. Equipment tests made in accordance with IEC 61000-3-11 are type tests. Advanced Test Equipment Rentals can perform ISO17025 accredited calibration on products that abide by this standard. NOTE: The flicker limits specified in this part, the same as those in IEC 61000-3-3, are based on the subjective severity of the flicker imposed on the light from 230 V/60 W coiled-coil filament lamps when subjected to fluctuations of the supply voltage. For systems with nominal voltages less than 220 V, line-to-neutral and/or frequency of 60 Hz, the limits and reference circuit values are under consideration.

IEC 61000-3-12 deals with the limitation of harmonic currents injected into the public supply system. The limits given in this International Standard are applicable to electrical and electronic equipment with a rated input current exceeding 16 A and up to and including 75 A per phase, intended to be connected to public low-voltage a.c. distribution systems of the following types:   Nominal voltage up to 240 V, single-phase, two or three wires; Nominal voltage up to 690 V, three-phase, three or four wires; Nominal frequency 50 Hz or 60 Hz. Other distribution systems are excluded. The limits given in IEC 61000-3-12 apply to equipment when connected to 230/400 V, 50 Hz systems. IEC 61000-3-12 applies to equipment intended to be connected to low-voltage systems interfacing with the public supply at the low-voltage level. It does not apply to equipment intended to be connected only to private low-voltage systems interfacing with the public supply only at the medium- or high-voltage level. IEC 61000-3-12 defines: a) Requirements and emission limits for equipment; b) Methods for type tests and simulations. Tests according to this International Standard are type tests of complete pieces of equipment. Conformity with this standard can also be determined by validated simulations. This second edition cancels and replaces the first edition published in 2004 and constitutes a technical revision. The significant technical changes with respect to the previous edition are: The replacement of the reference fundamental current I1 by the reference current Iref for the calculation of emission limits; A newly added table of current emission limits; A newly added annex (Annex A) to define test conditions for some types of equipment; Deletion of the former Annexes B (Approximate interpolation formulas) and D (Information on the PWHD factor). Retrieved 3/12/14 from IEC Webstore Note: Advanced Test Equipment Rentals can perform ISO17025 accredited

IEC 61000-4-34 defines the immunity test methods and range of preferred test levels for electrical and electronic equipment connected to low-voltage power supply networks for voltage dips, short interruptions, and voltage variations. This standard applies to electrical and electronic equipment having a rated input current exceeding 16 A per phase, for connection to 50 Hz or 60 Hz A.C. networks. It does not apply to electrical and electronic equipment for connection to 400 Hz A.C. networks. Tests for these networks will be covered by future IEC standards. The object of this standard is to establish a common reference for evaluating the immunity of electrical and electronic equipment when subjected to voltage dips, short interruptions and voltage variations. This second edition cancels and replaces the first edition published in 1994 and its amendment 1 (2000). This second edition constitutes a technical revision in which: Preferred test values and durations have been added for the different environment classes. Tests for the three-phase systems have been specified. It has the status of a Basic EMC Publication in accordance with IEC Guide 107.   Dips and Interrupts Background Dips and interrupts can occur on AC power mains as a result of a fault in the distribution system such as an open circuit breaker or a sudden large load being turned on in the immediate vicinity. A power distribution system fault can cause a switch in the distribution grid to open and close a number of times, resulting in multiple interrupts to electrical and electronic equipment. Electronic products are tested for immunity to dips and interrupts to insure their continued reliable operation if subjected to dips and/or interrupts on the AC power mains. The European Union’s EMC Directive mandates dips and interrupts testing for virtually all electrical and electronic products as a condition for obtaining the CE Mark before shipping products to member states of