How is the power rating of the SW-1/2 switches affected by multi-gang boxes?
One SW-1 switch or SW-2 base mounted in a single-gang box is rated at 600W. Mounting two switches in a dual-gang box de-rates each switch to 500W. Mounting three or more switches in a multi-gang box de-rates each switch to 500W. A single dimmer in a dual-gang box carries a rating of 800W. A single dimmer in a triple-gang box carries a 900W rating. 2 dimmers in a triple-gang box carry ratings of 700W each.