In article ,
William Sommerwerck wrote:
Can you have the double-insulated symbol on
a product with exposed 20V AC conductors?

Because humans aren't likely to be electrocuted by 20V, AC or DC.

But this does raise a question... What about insulation between the
primary and secondary windings? Its failure could put line voltage on
the secondary.

Depends on transformer design - assuming it does use one.

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*For every action, there is an equal and opposite criticism *

Dave Plowman London SW
To e-mail, change noise into sound.