Isolated mains power

[Fixup]

Hi,

I have many times needed isolated mains power for to make repairs safer. I found two identical transformers and decided to first transform down the voltage with the first transformer and then transform it back to mains with the other. In the same I added A DC power to the same box. The pictures below describe more   

[nctnico]

OMG  Another one who thinks an isolation transformer will keep him alive. FFS: Get differential probes with proper CAT rating and use a ground fault interrupter in the mains connection!

[rsee]

I might just be tired, but why are you connecting your "isolated main" ground to the source ground?  That would make it so they no longer have galvanic isolation. Also I agree need for the GFI.

[vk6zgo]

OMG  Another one who thinks an isolation transformer will keep him alive. FFS: Get differential probes with proper CAT rating and use a ground fault interrupter in the mains connection!

Congratulations on being the only soldier in step in the whole parade.

Isolation transformers have been used  successfully for decades by knowledgeable techs whose employers cannot afford differential probes.
Maybe a Noob might come to grief with one,but they will probably do so with a diff probe as well.

[Fixup]

I agree about that the ground connection is NOT safe to have to the Isolated side. This socket was just added if I might find some use for it where I want the mains ground from primary side. In all cases when you are working with mains power you need to be careful. Since immediately when you hook up some USB cable or oscilloscope to the device under test it will have a return path and its "not nice" (Dangerous) to be the return path for the current.   
Isolation probes would be nice to have, aside with the isolation transformer.
I have understood that you should only connect the device under test to the isolation transformer and NOT the oscilloscope.

 

[RGB255_0_0]

Isolate yourself. Connect it to a fast acting RCD/GFCI. Only use one hand.

Isolated or not, what saves your life is killing the power in a fault. Don't work around where metal work is ahs don't wear metal that could help electricity pass in or out.

Again, isolation transformer doesn't mean it's safe and you have to be very careful about bonding the isolation earth back onto system earth as stated.