So, if I have a Crown Cdi1000 and Ch2 (500W) is set to 70v, is the wattage on the main speaker wire equal to what the taps are set?

For example, I have 4 sat's each tapped at 15w. Is then only 60W total power then riding on that speaker line? I ask since I need to add another TPD surge speaker line suppressor (only connected to the 70v channel) and there is the 250w model and the 1000w model. Amp puts out 500W but if taps settings restricts watt output and is below 250W I can then use the lower wattage unit. Wasn't sure in a 70V system.