Hi All,

I've had a debate recently and would like the communities thoughts, as the engineering technician who is responsible for electrical isolations and contractor working safety at my site, I have performed the necessary isolations for the contractor to work on a roof fan.

Despite ensuring safety, I still always request the contractors perform a quick voltage test before touching any wiring, however, the contractor said he doesn't need to because if the motor "running" then that means there's no voltage. We debates this for a while before I let him do his thing.

I could think of a few scenarios where a motor has had voltage there and not ran in my real life experience, yet I'd like to also know everyone's thoughts on this from the technical side.

Thank you.