O:Yes, this is normal.
The power supply supports the iCOOL Intelligent Fan Control Mode.
When "iCOOL Mode" is enabled, the power supply operates in an energy-saving manner, allowing the fan to remain off during low to moderate loads. The fan will only activate when the power load increases or the temperature rises above a certain threshold.

This feature operates in "Auto" mode by default, but certain models feature or include an iCOOL Intelligent Fan Control Mode switch. You can refer to the specifications of your selected model to determine whether it operates automatically or includes the iCOOL Intelligent Fan Control Mode switch.