Can you substitute a 300 w halogen bulb for a 500 w?

Answer 1

If both are designed to run on the same source voltage, then they're interchangeable,

but the 300-w unit will produce less light than the 500-w unit.

Note:

If the mechanical designs are identical, i.e. they can both mount in the same receptacle,

then they're most likely designed to run on the same source voltage. Lamps designed for

different voltages are usually built with different mechanical designs so that they can't

fit into the same socket. It's assumed that most users are too careless to check their

bulbs, and that they'll routinely install anything into any place it fits.