Transformer shields not connected to anything

[cupoftea]

Hi,
We have been given a 500W PFCd Full Bridge to bring up. 115vac, 28vout, 200khz pfc 250khz FullBridge.
The Full Bridge transforner is wound with ECW everywhere.
No margin tape.
They have used copper foil shields between the layers.....(fortunatey these are not shorted turns)
However, they are floating, not connected to anything.
Transformer is 30:6
(15:6:15)
Foil shields between all layers.
Do you agree the foil shields do no good?

 

[mtwieg]

It is strange that they would be left unconnected, but can't be certain they do "no good" without actually testing with/without the shields.

 

[andre_luis]

To be honest, I don't see much advantage on grounding interwindings if the outer foil is already grounded.

 

[Easy peasy]

" To be honest, I don't see much advantage on grounding interwindings if the outer foil is already grounded. "

it is to reduce CM propagation.

--- Updated Nov 29, 2022 ---

foil shields can aid in moving heat from the middle of the Tx to the outer regions ...