I have a multiplus 24/3000 and want to power a refrigerator that uses 603 watts per 24hour. I assume i will draw 639 watts since the Multiplus is 94% efficient. Am I correct? Also since the Multiplus will have to remain on for that 24 hour period will I also draw an additional 20 watts per hour 480watts in stand by consumption for an expected 1190 watts in a 24 hour period? Would AES lower this much?