Am I correct in thinking that if a rcd feeds a transformer, then anything connected to the secondary of the transformer will not be protected by the rcd and another rcd is required to provide protection
sorry just to be clear an rcd on the primary of an auto transformer would provide protection to secondary circuits as they are electrically connected
An rcd on the primary of a normal transformer ie two electrically isolated coils would not provide protection to the circuits on the secondary
is that correct