The power limit parameter is the step value of active power, which is less than the total power. As long as the active power of your appliance is less than 400W, it has no influence. Generally, the power of a notebook computer will not exceed 200W, that is, tens of W. As long as you don't turn on the appliance at once, there will be no problem. The active power with rapid temperature rise is generally 1200W, so it cannot be used. Hair dryers with power less than 400W can be used normally, while hair dryers with power greater than 400W can only use cold air or low-grade hot air.