You know what it's like

[Pete999]

As the title suggests you know what it's like when you are bored and start thinking of times past.
A 230 V supply feeding an isolation Transformer 230V /23OV feeding some equipment, on the Secondary side of the TX a DP RCD is fitted, question if the RCD sees a fault on the equipment will it trip on an Earth fault? the Secondary output is center tapped 110V each side of the Earth.

 

[Deleted member 26818]

Yes.

 

[davesparks]

Yes because the centre tap is connected to earth so the output is not isolated from earth.

 

[Pete999]

Yes.

Thabks

Yes because the centre tap is connected to earth so the output is not isolated from earth.

Thanks

 

[Squid]

You set me off Pete, Gwen the 5' 11" half Canadian half Japanese exotic dancer that I had a "dalliance" with 25 years ago........

 

[Pete999]

You set me off Pete, Gwen the 5' 11" half Canadian half Japanese exotic dancer that I had a "dalliance" with 25 years ago........

And? more please

 

[Silly Sausage]

You set me off Pete, Gwen the 5' 11" half Canadian half Japanese exotic dancer that I had a "dalliance" with 25 years ago........

I've got say, when thinking of times past, centre tapped transformers aren't really the first things that springs to mind

 

[Pete999]

I've got say, when thinking of times past, centre tapped transformers aren't really the first things that springs to mind

Yeah well when your memory aint working that well, go with what comes to mind first before you forget it.

 

[ipf]

Yeah well when your memory aint working that well, go with what comes to mind first before you forget it.

I'll go with that...…. then again, I can probably remember stand out times 4 decades ago better than 4 months back.......but 4 seconds???? Sounds like it's when you nip out to the wholesalers, arrive and then can't remember what you've come for

 

[Pete999]

Yes because the centre tap is connected to earth so the output is not isolated from earth.

What about if the output volts was 110V Center tapped 55 V each side of earth?

 

[davesparks]

What about if the output volts was 110V Center tapped 55 V each side of earth?

It will trip because the output is still referenced to earth, assuming its a regular rcd which will operate at any voltage up to its rated maximum.

 

[Lucien Nunes]

An RCD will work downstream of a transformer provided one point on the secondary is earth-referenced (and connected to the load CPC if present.) If that point is also used as a neutral, then the N-E link must be between the transformer and the RCD. E.g. on a 230V TN system, the earth-referenced point is also the neutral; the N goes through the RCD but the CPC does not. On a 55-0-55 site supply, the centre-tap is not used as a neutral but it is still earth-referenced so the RCD will react to a fault on either line.

On non-standard voltages between the outers, the RCD test button may not behave correctly as it will pass the wrong test current.

 

[Squid]

Is Pete manufacturing some sort of bomb in his workshop?