Can you send me a manual for maintenance of a constant voltage projection welding machine?

There are articles on constant voltage and constant current in this blog:

WHAT IS CONSTANT CURRENT?

WHAT IS CONSTANT VOLTAGE?

SHOULD CONSTANT CURRENT EVER BE USED FOR PROJECTION WELDING?

These explain the advantages of using constant voltage and constant current.

  PROJECTION NUT WELD

This blog deals with the resistance welding process. It does not offer any input on manuals set up or maintenance of individual machines. Consult your local machine dealer or manufacturer for assistance.

Reference: RWMA Resistance Welding Manual 4th Edition