When you choose an industrial power supply, it's important to consider whether the unit will withstand the conditions it might encounter. Threats like extreme temperatures, dust, liquids, shock and vibration quickly come to mind in industrial applications. However, you would be remiss if you don’t also ask yourself about the altitude at which the supply will operate. Power components behave differently at higher altitudes than at sea level.
Close to sea level, air is a good insulator inside a power supply. But at thousands of meters in altitude, barometric pressure is lower and air loses some of its insulating properties — its dielectric strength. Thin air with low dielectric strength can cause unintended breakdown voltage or arcing, which can present safety concerns for personnel as well as risk of equipment failure. Higher altitude also diminishes the cooling action of air, making heat removal difficult.
How Power Supplies Account for Altitude
Be sure to ask your power supply vendor or check the datasheet to make sure the unit is right for its operating altitude. Power supply manufacturers address altitude by how they separate their internal components. That means they allow for additional clearance — the shortest distance between components through the air, and creepage — the shortest distance along an insulating material (such as the circuit board) common to two parts. The higher the altitude, the greater the separation required between components. In addition to checking the operating altitude on the datasheet, verify that it meets the regulatory standards for altitude in its intended country and industry, such as medical.
Polytron Devices’ KUI30 Series is a good example of an industrial power supply for high elevations. These universal input, 30-W AC/DC power supplies with a wide-input voltage range of 85 to 264V DC have been designed for an operating altitude of 5,000 meters and provide 3,000V AC of reinforced insulation. Available in open-frame design (KUIO30) and encapsulated (KUI30) versions, these Protection Class II supplies also feature:
- Up to 91.5 percent efficiency.
- An adjustable output voltage.
- Low leakage current.
- Low standby power.
- UL/EN/IEC 60950-1 approval.
- Over current, over voltage and short circuit protection.
Don’t Overlook Altitude
Dirt, shock, vibration and temperature are all important conditions to consider when selecting an industrial power supply. One additional factor — operating altitude — should not be overlooked. Polytron Devices’ KUI30 AC/DC power supplies account for thinner air and offer several protective features that make them desirable for industrial applications where high-altitude operation is a concern.
For more information about Polytron Devices’ KUI30 Series AC/DC power supplies, visit the product page.