I want to get an dc to ac inverter to power a number of different ac tools / equipment / machines (not all at the same time). What level of distortion is acceptable for what applications and are there any easy/cheap ways to reduce distortion from a given inverter if necessary?

 

If there's a better/other way of defining cleanliness than thd then please say

 

THD is perfectly acceptable to define AC line distortion. This reference (last page) suggest a 3% maximum distortion for any one harmonic with a total of 5% maximum TDH. Note that's just a recommendation, not a power line requirement.