Pulling new wire/cables in conduit with existing 120V energized wire/cable.

[augie47]

I know it's "old school" but I dare count the number of times I've used infinity's method successfully...with the existing circuit de-energized when practical. In doing so you have to evaluate the system.. size of conductors and conduit, number of conductors, etc. Experience will dictate the chances of success.
On occasion that plan didn't work and I had to pull back and go to plan "B"
Likely not permissible in today's world but common practice with my group of old timers.

 

[drcampbell]

... I don't know [if the hiring contractor can be held liable when a sub contractor messes up], but I would say it's sort of doesn't really matter because the insurance companies will hash it out.

That may be the protocol for relatively small contractors, but I don't think it's applicable to a corporation large enough to own a nuclear powerplant. The work is being done in-house, not for a customer; they're likely to be self-insured; (until the mishap is large enough for Price-Anderson to come into play) and they're under the jurisdiction of the Nuclear Regulatory Commission, in addition to OSHA.

 

[electrofelon]

That may be the protocol for relatively small contractors, but I don't think it's applicable to a corporation large enough to own a nuclear powerplant. The work is being done in-house, not for a customer; they're likely to be self-insured; (until the mishap is large enough for Price-Anderson to come into play) and they're under the jurisdiction of the Nuclear Regulatory Commission, in addition to OSHA.

I was talking generally and not specifically about the nuke plant scenario.

 

[garbo]

If that circuit is so critical that they can't schedule a safe shutdown, what will happen if it faults out during the pull?

Worked at 2 fortune 500 companies during my 50 enjoyable years as a sparky. First one had no trouble scheduling off hours shutdowns and paying overtime for it. Second company seldom gave overtime for any non emergency work. Would want you to change your shift or take a day off during the week and expect you to work by yourself on Sundays. Also they were too cheap to supply any PPE so I refused to open covers on all energized panels. Second tap times they expected me to remove 7' high heavy covers in 800 & 1,200 panels by myself. Every time I did ask for my own set if rubber gloves with canvas protection gloves said they were looking into it but would only have money to purchase a single pair where the 5 electrons spread over two shifts would have to share. Told them No Today or any day. Told them that sharing rubber gloves us worst then sharing a toothbrush or underwear.