I'm designing a sensor triggered circuit that involves 220 V passing on a PCB, so I designed the board thickness to withstand a maximum of 1.5 A. The main load on the circuit would be a series of LED bulbs, each bulb draws 4 W (says on package). I'm confused on calculating the maximum bulbs I can attach to the load, I'm guessing its one of those scenarios:

Max load = 1.5A / current per bulb = 1.5 / (4/220) = 82 bulbs

Or does the manufacturer calculate power drawn from voltage regulator (5 V) and thus:

Max Load = 1.5A / Current per Bulb = 1.5 / (4/5) = 1.8 bulb = 1 bulb.