Having not read the OSHA regs, I have a question: just what defines 'working hot'. By the most broad definition, _everyone_ 'works hot'. When was the last time that you switched off a breaker before plugging something in
I certainly don't expect that PPE is required prior to turning on a light switch. Yet there is a _very_ _very_small risk of shock or arc-flash from either of these operations.
One of the points raised in this discussion is that it really is not very practicable to use 'proper' PPE all the time. But the solution to this can go in two directions. 1) Simply not use the PPE and accept the increased risk, or 2) start designing equipment so that the risk presented by the equipment is much lower, such that appropriate PPE is less expensive/more comfortable/more convenient.
The example given above of a panelboard with its main breaker 'off' is a perfect situation to examine. Clearly, even with the main breaker off there are energized conductors in the panel. But IMHO the presence of energized conductors is not enough to say 'this is hot work'. One would need to additionally examine if the conductors are protected from accidental contact or not.
IMHO if, in a given panel, the feeder conductors are as protected from accidental contact as the energized metal in a receptacle, then working in such a panel with its main breaker off is _not_ working hot.
On the other hand, if there is significant exposure of energized conductor, then working in such a panel, even with the main breaker off, would be working hot.
Taking this to the extreme, if the panel is a 'live front' switchboard with exposed blade switches and wires, then _normal_ use of the panel is IMHO hot work that should require PPE.
Going to the other extreme, it seems clear to me that a panel could be designed with protected bus stabs, finger safe breaker terminations, etc, such that one could change breakers, install new circuits, etc., and _never_ require more PPE than safety glasses. I know of no panel that would meet such a standard, but I see no reason that this would be impossible. Such a panel might be more trouble/expense than benefit, and to answer that question would require lots of research...but small changes, eg. finger guarding at terminals, or internal cover plates that guard the bus but permit access to other parts of the panel, could reduce the need for PPE without being very expensive.
Please note: I am not making an interpretation of what the OSHA rules _say_, I am stating what I believe would be an ideal case, and suggesting that appropriate protection be considered for equipment at the design/installation stages specifically to reduce the need for PPE during later work.
-Jon
