Help! What does this symbol mean?

[Ste1978]

I've not come accross this before, at first I thought it was a relay but now I am unsure. Could be power supply.

Any ideas?

[dbroada]

It looks like an AC motor to be but...

by EN60617-6:1996 a circle is a "machine" and should also have a letter noting that it is a motor, generator etc. and a number in front of the sine wave to tell how many phases.

I think L1 & L2 are American for L & N.