Based on our experience....I'd totally avoid the.."simple transformers". We bought 2 of them, sized for the load (in watts)we thought we'd pull, paid the shipping
(they're heavy) to the boat
in Puerto Rico
, and plugged them in. The first one worked fine, converted the 110v to 230v just as we needed, and it lasted about 10 days! No obvious faults or signs, no evidence of o'heating, no burned wires, no smell...nothing....it just quit! Bought another one, this time 2x the size of the previous...and it lasted almost 3 weeks! I have no idea what killed them, maybe it was that quality build from China
that ebay sells so well(??) but neither worked out. As I mentioned, we bought a Victron Isolation xfmr, installed it, and it's worked perfectly now for almost 3 years, ...'Guess it pays to buy something designed for the environment
and use you intend to put it to!