Ambient temperature and output power

Our standard operating temperature range is -25 to +55°C with 100% load. It means that the temperature around the case has that temperature. Our DC/DC converters has relatively large coolers which provides some thermal after lag. Therefore temporary temperature peaks outside the range can be accepted. E.g. the railway standards EN50155 demands 15°C increase during 10 minutes. Operating temperature up to +70°C can be achieved with derating and with forced air cooling up to 85°C. See below figure. The PSC and PSE series are specified up to +70°C without derating. Please note that the life expectancy of a power supply unit is very linked to the ambient temperature. A rule of thumb is that 8-10°C temperature increase halves the life expectancy. In reality this is valid from about 30-40°C ambient temperature. -40°C is optional as we need to test that the unit starts at this temperature.

Last Updated on Monday, 04 January 2010 08:45