driftsforhold

Driftsforhold, a term used in Swedish and Norwegian technical literature, refers to the conditions under which a device, system or process operates. It encompasses environmental, mechanical and electrical factors, as well as operational aspects such as duty cycle and maintenance intervals. In English, the closest equivalents are operating conditions or environmental envelope.

Environmental factors include temperature, humidity, air quality, dust and corrosivity; mechanical factors cover vibration, shock and load; electrical factors involve supply voltage, frequency, outages and harmonics. The driftsforhold also describe how these factors may interact with the equipment’s design, materials and protective measures such as insulation and sealing. Documentation of driftsforhold is common in datasheets, manuals and test reports for complex systems.

Driftsforhold are used during design, testing and procurement to ensure reliability, safety and performance within specified limits. Engineers define acceptable ranges in datasheets and manuals, and testing standards simulate these conditions to verify function, endurance and safety. Exceeding the stated driftsforhold can increase the risk of premature failure and may affect warranties or regulatory compliance.

Examples illustrate typical content. An electric motor might specify ambient temperature -20 to 40 C, relative humidity 0-95% non-condensing, altitude up to 2000 m, electrical supply 400 V three-phase 50 Hz, and continuous operation (duty cycle S1). More demanding equipment, such as aviation or oilfield gear, often uses stricter envelopes, including pressure, vibration, and exposure to corrosive atmospheres.

See also: operating envelope, environmental testing, qualification, duty cycle.