Electronics Weekly
The power supplies do not have an internal fan, and 550W is only achievable with both baseplate and blown air cooling above 21.9cfm, with derating starting at 50°C ambient, and the maximum allowable load dropping to 350W at 80°C.
With un-blown ambient air, these are 450W PSUs with derating starting at 50°C, dropping to ~240W at 80°C.
These figures are when attached to an external 381 x 381 x 2mm baseplate. Maximum allowable case temperature is 90°C, and minimum temperature is -40°C.
LFM550S types are intended for industrial use (to IEC/EN/UL 62368-1) and LFM550M types are aimed at IEC/EN/UL 60601-1 medical applications.
Different variants offer a choice of 12, 15, 24, 28, 30, 36, 48 or 54V at the output, with voltage adjustable over ±5%, except in 28V types which are -0% +5%. Peak efficiency ranges from 92 to 94% depending on output voltage type.
Operation is over inputs of 100 to 240Vac and 47 to 63Hz – check the data sheet for caveats.
Active power factor correction is included and the supplies meet over-voltage categories OVC II and OVC III.
They comply with CISPR/FCC Class B EMI, according to Relec, which is stocking the parts.
Operation is over -40°C to +90°C· Operates at up to 5000m altitude.
