What does this symbol mean?

[BobParticipant @bob17059]

Symbol on casing of isolation transformer

[BobParticipant @bob17059]

What does this symbol indicate?

[KWILParticipant @kwil]

I am sure it shows what it says. Two identical windings, 1:1 ratio, Completely isolated for safety. In other words an isolation transformer.

[BobParticipant @bob17059]

I agree that the two overlapping circles with the the two downward pointing 'legs' represent an isolation transformer but what does the enclosing semicircle signify?

[Bill Davies 2Participant @billdavies2]

See: Isolating transformer symbols (IEC standards).

Seems to be a slightly corrupted version of Pr01-029.

Bill

[BobParticipant @bob17059]

Many thanks Bill. I have never come across these symbols before and they are not very intuitive. I guess the semicircle is meant to represent a hard hat that would be worn on a construction site.

Bob

[Robert Atkinson 2Participant @robertatkinson2]

Typical IEC. Weird symbols the meaning of which is hidden in a expensive document. The linked document shows p proposed symbols, I wonder what they settled on. And no I'm not going to pay BSI £356 for EN 60417 to find out. Oh and that price is only for Part 2, Part 1 is an additional £356!

Robert.

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