Is it required that the lock out tag out be done by the individual working on that circuit? Or is this just good practice (Can another electrician lock and tag out the circuit for you.)- I've done this many times
Anyone can take out the LOTO - BUT YOU SHOULD ALWAYS PUT YOUR OWN LOCK ON ALSO.
Imagine a conveyor system with millwrights and electricians all working the same equipment..millright takes the LOTO, you add an additional LOTO and lock. The equipment cannot become "live" until ALL locks have been removed.
I would NOT rely on "someone else" to watch my back ie, another electrician watching the CB. His phone might ring, service is crappy, he walks around corner; a pretty girl walks by ~ he starts watching her and takes a few steps; he needs a bathroom; ...this could go on and on. A lock stays where it is put.
Every company/customer will have a LOTO policy(in writing). If for some reason they do not, YOU should have a LOTO procedure. If the customer does have a LOTO policy, your lock will not diminish the value of their procedure.