"Tough Guy no. 1265" wrote in message
news
On Sun, 08 Nov 2015 12:44:54 -0000, Dave Plowman (News)
wrote:

In article ,
Tough Guy no. 1265 wrote:
Why do builders have isolating transformers then?

Generally, because the tools are 110v.

Going back years in TV studios, any domestic equipment or musical
instrument that needed mains power was fed via an isolating transformer.

These days, using an RCD provides the same safety requirement, and at
far less cost.

Why would a TV studio be a dangerous environment?

It wasn't done that way because of the danger.