Switching off a transformers from two sides

[electrics]

Hello, in a regulation of my country about electrical installations it says overvoltages can be avoided by
" avoiding switching off no-load transformers circuits from two sides"
does it make sense for you? or is there any possibility that this phrase tries to tell something alike...

 

[rcwilson]

Does it mean avoid ferro-resonance of three-phase connected transformers by using a three-phase switch or breaker to open the circuit? On some designs of transformers, disconnecting one phase at a time can cause ferro-resonance that creates overvoltages.

Otherwise, I don't understand the comment.

 

[jghrist]

Hello, in a regulation of my country about electrical installations it says overvoltages can be avoided by
" avoiding switching off no-load transformers circuits from two sides"
does it make sense for you? or is there any possibility that this phrase tries to tell something alike...

I'd try to find a copy of the regulation written in the writer's native language.