I am looking at wet dry vacuums and there is one that says 5 HP at 9 amps ;180 watts.... I saw some that claim 1.75 HP, but how can I tell what the real power use is? and there is another "The vac is 3.5 HP and 175 watts" ???? and what is 1.75 Peak HP ? Well of course they don't say the efficiency %..... I have a dry vacuum that says 12 amps , But that seems a lot for off grid use. I have about 300 to 350ft of 10g wire. What is going to burn out the wire?