Not sure what country you operate from. My experience is in the USA but all 110-120v countries should be similar.
Skip the transformer. Hire an electrician to install 240 volt circuits. Your power panel should have a 240 volt main breaker. Homes in the US typically have 100 amps, 200 amps, or 400 amps of 240v at the main panel. The main breaker turns off all the power to your house.
Commercial buildings usually have much more power.
An electrician should be able to peel one or more 240 volt circuits from your panel and wire outlets to where you need them.
Figure out the amps you need for your miners and be sure to apply the 80% derating rule for continuous use (required by code). For example, a 30 amp breaker can only run 24 amps on a continuous load.
Good luck.