jraef
Member
It says right on that posted chart that they are basing this on "industry standards of efficiency ranging from 20% to 60%" (sic). Those are absolutely horrible values to use, but if your goal is to convince people to buy larger SSRs, it makes perfect sense... To give them the benefit of the doubt however, they have no idea what TYPE of single phase motor you are going to use, so they are somewhat justified in basing this on "worst case scenario" values. Small Shaded Pole type motors can in fact be horribly inefficient, but for 1/8HP, who cares? In your case at 0.9kW (about 1.2HP) it's likely around 70-80% eff.