Dc welder with dc receptacles

[Jpflex]

Based on wiring diagram I believe arc welder generator output from field windings supply input to smaller dc generator feeding 120v dc receptacles.

Does battery 12v dc then feed larger arc welder for exciting field current at the point shown at finger and what does this symbol mean ( where pointed at switch?)

 

[Jpflex]

What does this symbol mean? Is it a switch or what is meant by two and 3?

 

[Jpflex]

Generator controls

 

[drcampbell]

Looks like a multi-position switch, drawn by a draftsperson whose day job is hydraulics.
Just a guess; do not rely on this without independent verification, such as tracing the wires yourself.

 

[synchro]

What does this symbol mean? Is it a switch or what is meant by two and 3?

I believe it's a current sensor (probably a Hall effect one which works at DC), and the 3 turns of wire are placed through its open aperture.