Led power supplies
Ribbons and some led lights work at low voltage (12 or 24V). The power supplies transform the 230V AC mains current into 12 or 24V DC.
The power is a fundamental parameter for the choice of a power supply. The values indicated on the transformers correspond to the MAX power that they can deliver.
Using the power supply at its maximum value greatly reduces its service life. It is therefore strongly advised to take a margin of 30% to make it work at its nominal value.
Example: If your light device consumes 115W, the power supply will be: 115 + 30% = 150W.