How Does Altitude Affect AC-DC Power Supplies?

Most AC-DC power materials that meet the protection standards in step with UL/EN 60950-1 for ITE (Information Technology Equipment) applications are designed to perform at the typical workplace and factory altitudes, that may vary from barely above sea degree to as high as 2,000 meters (6,562 feet). And, many energies deliver producers provide gadgets that are designed and rated for operation at higher altitudes, as much as 3,000 meters (9,843 feet) so their resources may be used in fundamental cities positioned at better elevations (e.G., Denver, Santa Fe, Mexico City, Bogota). Many broadcasting/communications stations/towers are placed at altitudes up to 3,000 meters or higher so that you can maximize their range.

Altitude affects the layout of power supplies in view that ‘air’ is used as an electric-powered insulating medium (aka, dielectric) inside the production of energy materials, as nicely as maximum electronic devices. The density and dielectric strength (insulating property) of air is superb at sea level, but at higher altitudes, the thinner air loses some of its dielectric strength, which wishes to be compensated for. Switchmode strength components function off of high voltages (inputs of 90 to 265Vac) and internally generate even higher voltages (400Vdc or more), which want to be insulated and contained to prevent excessive voltage arcing or breakdown in the delivery, and to defend the end-system and working personnel. power strut vs unistrut

The drawing under shows a cross-phase of a typical revealed circuit board (PCB), which is constructed from copper electric conduction paths that our chemically etched on an insulated (dielectric) fiberboard material (e.G., FR4, woven fiberglass fabric with epoxy resin), plus electronic additives that aren't shown on this drawing. As can be seen, the fiberboard and air, mixed with the distances among the etched conductive traces are the primary insulation mediums for the circuit board.

The term ‘Clearance’ refers to a shortage path between the two conductive components (circuit lines, components, etc.), measured via air.
The term ‘Creepage’ refers back to the shortage path among conductive elements measured alongside the floor of the insulation (PCB, insulating materials/barriers, etc.).

What does this ought to do with altitude? Since ‘air’ gets thinner (reduced barometric pressure) at better altitudes and turns into less of an insulator, the PCB and issue layouts must be designed with enough protection spacing distances to save you high voltage arcs or breakdowns between conductors and/or digital additives. ps 200 eh 10 pgal

For example, typical electricity delivers design exercise that may permit an eight mm spacing distance between number one and secondary circuits and four mm spacing distance between primary and ground. These spacing distances will range relying upon the voltage ranges between conductors and components and the predicted humidity, temperatures, pollution tiers, and attitudes.

For that energy merchandise that should be approved according to the Chinese CCC organization (required to export substances into China), the new Chinese Safety Standard GB 4943.1-2011, which is just like UL/EN 60950, ps 1100 requires strict specifications for creepage and clearance distances. As of December 1, 2012, the number one-to-secondary clearances ought to grow via an issue of 1.48 to qualify the supply for operation up to 5,000 meters, considering many areas in China are located at high altitudes. The opportunity for CCC certified electricity supplies is that they have to marked with a warning label that states that the strength deliver should be used beneath 2,000 meters

The other principal impact of high altitudes on strength materials is that the much less dense air does now not conduct warmth as nicely. To compensate for better altitudes, electricity resources need to be derated, or employ large heat sinks, or have increased compelled airflow, or a combination of those to ensure proper cooling. Also, the electricity delivery needs to be designed with the proper conductor and component clearances as discussed above.

In summary, whenever an application requires that a power supply should perform at altitudes above 2,000 meters (6,562 feet), always take a look at with the manufacturer to decide if that is acceptable, or if a change model is designed for higher altitudes is required.