I've been looking for a suitable isolation transformer to solve the
pesky shore power issues with marinas in Caribbean ports. Typically
they offer 240 volt power with no neutral center tap, 50 Hz of course.
We also run into docks with overly sensitive ground fault interrupters
(GFIs). An isolation transformer can potentially solve both of those
problems. I just scored one like this on EBAY for $125:

http://www.zoro.com/acme-electric-export-transformer-5kva-120240v-wall-tf279263s/i/G2913784/?gclid=CNSH0ZvYxMgCFUqRHwodo9oBhg

It's good for 5 KVA which should be enough for one or two zones of air
conditioning plus the battery chargers and water heater. I'll build a
water tight box out of starboard and put US style 50 amp in/out
connectors on it. With some suitable pig tail adapters it should be
good for just about anywhere. A 10 KVA transformer would be better
but weight, size and cost issues are prohibitive.