I am sorry if this is covered in another message, but my searches could not find it. I am struggling with OSHA regulations which state that all electrical work 50 volts and above must be de-energized unless it meets certain criteria, which the majority of time no one can claim those exceptions. We have completed all our arc flash analysis and in the case, where I want to do live work there is no arc flash concern as we want to do live work on a 120/208 volt panel fed from a 15 kVA transformer. Regardless of the low arc flash hazard, I am being told the generic OSHA statement is preventing us from doing live work, because OSHA we are above 50 volts. If OSHA means this, then anytime someone plugs in a printer or coffee maker at work they are breaking OSHA regulations. If this is really what OSHA wants how do you prevent people from unplugging their laptop to take out of the office. If they get shocked you are breaking OSHA regulations and there could be a huge fine. This just doesn't seem practical to me. Any ideas?

50V is a shock hazard threshold, not an arc flash hazard threshold.

Thank you for the response and I understand at this voltage level OSHA is only talking about a shock hazard. What I didn't understand is if OSHA really intends to have no live work on 50V systems and above. If they truly mean this, minus a few exceptions, then in reality every company across the US needs to lock down or remove every receptacle in their buildings. Plugging in a phone charge briefly exposes a live connection and a shock hazard exists. Which means plugging a phone charger into an outlet is breaking OSHA regulation. This doesn't seem logical to me and I have been searching for any information that tells me I am wrong and this is not OSHA's intent. I hope I just have search engine overload, where I am not using the right keywords and finding all sorts of information, but not specific to what I really want, so far I have found no exceptions to say yes a shock hazard exists, just prepare for it and continue your live work.

With Arc flash it is all about determining and understanding the risk and providing the appropriate protection, so you can be somewhat safe doing the work live. With OSHA I have not seen any comments or exceptions that state you can do live work if properly protected. They just say no live work, with a few exceptions and if that is truly how others see the regulation and it is set at 50 volts and above, then anytime something is plugged into a receptacle an OSHA violation has occurred.

What is the OSHA definition of "working on"?
After all, if no interaction is allowed at all, then even the use of an on-off switching device should be prohibited.

This is the part of the definition from NFPA70E, which is probably similar to OSHA's:
[quote]Working On (energized electrical conductors or circuit parts). Intentionally coming in contact with energized electrical conductors or circuit parts ....
There are two categories of “working on�: Diagnostic (testing) is taking readings or measurements of electrical equipment with approved test equipment that does not require making any physical change to the equipment; repair is any physical alteration of electrical equipment (such as making or tightening connections, removing or replacing components, etc.).[/unquote]

When using a plug and receptacle, there is no intention to contact energized parts nor to make physical changes.

Thank you for your comments, you have helped me understand this a little better and gave me another direction to do some research. This all started when my company interpreted the regulations such that if we need to add a circuit to a spare breaker in an existing panel we can do this live. Since the breaker is existing, we are not touching the live bus, only making connections to a breaker that is open.

However if we have to add a new breaker to an existing panel, then this cannot be done live as we are now making a connection to a live bus. This seems to match what you said, so that makes sense. I still need to investigate further because adding a molded case breaker to an existing panel, though the breaker will be touching the live bus, the person installing the breaker will not be touching the live bus. To me this is just like plugging something into an outlet. You are plugging something into a live bus, though the person is not physically touching the bus.

I greatly appreciate your comments and my search can now be focused on complete understanding of "working on". Thank you for taking the time to help

Making any connections is considered 'working on'.
To keep it simple, when covers are removed or doors opened, if tools are involved, then the activity involves 'working on' equipment.

Keep in mind if you do not use the exceptions, you can't work on it de-energized either. All electrical equipment is considered live until locked out using the electrical lockout procedure which is NOT a general lockout. The general lockout procedure even says it is not for electrical lockouts. The electrical lockout includes a step where the equipment is tested using a meter (diagnostic working on) to prove it is dead as the last step. It is working live during the test, placing jumpers, etc. So this qualifies as an exception.

70E goes beyond the shock hazard rule in OSHA regulations. Even there is no shock hazard (live equipment is insulated, isolated, or guarded...and these definitions are very specific...seeing metal is not a valid test), an arc flash hazard may still exist but it is task specific.

The concept of the energized work permit rule is not to prevent all work. It is adding a layer of procedures to get a second set of eyes (specifically management which is respnsible for providing a safe work environment) looking at the task and a set of guidelines for qualified workers to understand when the line is being crossed. This rule minimizes exposure as much as possible. Examples of where the exceptions would also apply would for instance be light poles and HVAC where de-energizing requires pulling fuses, most overhead line work (although 1910.269 has not EEWP rule), and some hazardous ventilation systems. I have also seen it applied where for instance a control panel is fed directly by a step-down transformer with no secondary disconnect where the breaker is on the transformer primary. The incident energy in the lighting panel is almost nonexistant but very high at the breaker. This meets the greater hazard exception.

By the way your example can definitely be live work. If the breaker is locked out and all energized conductors in the panel in the area being connected are not exposed then it could be de-energized work. But a lot of moving energized wiring around, blind fishing (with metal fish tape), drilling holes with metal shavings falling into the wrong places can go on. So you cannot say landing a wire on a breaker in a panelboard is categorically safe even if the breaker is off, but it can often be made that way.

Sorry to resurrect an old thread, but a question has come up at my facility. Would swapping a bad breaker for a good breaker on a lighting panel be considered live work? Didn't quite see that question answered yet in this thread.

IMHO I think that would be considered live work that needs to be justified.

Yes. This is live working (maintenance), same thing as racking a draw-out breaker in and out of the cell. In addition if you are replacing a bad breaker, there is a heightened possible risk since it could fail closed. I've found a few over time in this condition though it's a lot more rare than the always closed or won't stay closed condition. In both cases obviously though the equipment is specifically designed for this activity, particularly the snap-in variety, not so much the bolt on types. The issue moves on to the "greater hazard" and "feasibility" requirements. I think in one of the letters of interpretation they described an extensive shutdown process involving tons of additional potential hazard exposures which culmulatively might be greater than the energized work hazard. I'd also point out the cases where in this case the likelihood is very small for snap-in type breakers on par with opening or closing one. There may be a greater hazard (since likelihood is almost the same) in operating the larger upstream breaker which could qualify as justification. Hospitals frequently use something similar especially with respect to working on operating room equipment but this is being reconsidered in some places, especially in light of an incident where at least one electrician died and two others were severely injured in an arc flash in one of those multiple-bus multiple-source triple redundancy systems that hospitals often have where the bus impedance was particularly low and the breaker settings were particularly high.