The effect of altitude on the operation performance of low-voltage switchgear and controlgear components

Decreased air density due to increased altitude can have an effect on the operation performance of low-voltage switchgear and controlgear components. For applications at high altitude, little is known about this effect on the operation performance of these components. Characteristics such as dielectric voltage withstand, thermal ampacity, overload calibration, contact life, and interruption capability can be affected by the decreased air density. Tests were conducted in an electrical laboratory capable of producing needed electrical circuit parameters. The testing was conducted using a vacuum chamber to artificially lower the air density to simulate altitudes up to 6000 m. A fact-finding study was developed, defining the operation performance capabilities for low-voltage components at higher altitudes.