petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
You have two different hazards associated with electricity - electrocution and arc flash.
If you can somehow justify working live on a panel, the electrocution protection is relatively simple. Basically you wear the gloves and shoes, along with glasses and hat. It is not real hard to determine if you are exposed to an electrocution hazard either. If you are going close to an energized and exposed voltage over 50V, you are considered exposed and need to protect yourself from the hazard. There are very effective ways of reducing your exposure potential including use of guards such as finger safe design. People argue over them being imperfect, but they are pretty effective.
Personally, I think you are exposed if you are taking voltage measurements since your hands will be close to the exposed part of the probes being used unless the combination of the probes and the guards in use prevent this. Since the vast majority of the time you will be working on energized stuff will be for troubleshooting purposes, unless it is < 50V, by default you should probably consider yourself to be exposed to the hard of electrocution.
The arc flash hazard problem consists of two separate issues. One is how likely the hazard is to occur and the other is how severe it is likely to be if it occurs. You want to attack this problem from both sides. Guards can significantly reduce the risk of an arc flash incident happening. They do nothing to change the severity of a potential arc flash incident. There is a benefit in doing things that reduce the risk of an arc flash occurring even if it does not reduce the level of PPE required.
I am not convinced that just working within the arc flash boundary of a part like a switch that is completely enclosed and not being operated exposes one to an arc flash risk at all.
If you can somehow justify working live on a panel, the electrocution protection is relatively simple. Basically you wear the gloves and shoes, along with glasses and hat. It is not real hard to determine if you are exposed to an electrocution hazard either. If you are going close to an energized and exposed voltage over 50V, you are considered exposed and need to protect yourself from the hazard. There are very effective ways of reducing your exposure potential including use of guards such as finger safe design. People argue over them being imperfect, but they are pretty effective.
Personally, I think you are exposed if you are taking voltage measurements since your hands will be close to the exposed part of the probes being used unless the combination of the probes and the guards in use prevent this. Since the vast majority of the time you will be working on energized stuff will be for troubleshooting purposes, unless it is < 50V, by default you should probably consider yourself to be exposed to the hard of electrocution.
The arc flash hazard problem consists of two separate issues. One is how likely the hazard is to occur and the other is how severe it is likely to be if it occurs. You want to attack this problem from both sides. Guards can significantly reduce the risk of an arc flash incident happening. They do nothing to change the severity of a potential arc flash incident. There is a benefit in doing things that reduce the risk of an arc flash occurring even if it does not reduce the level of PPE required.
I am not convinced that just working within the arc flash boundary of a part like a switch that is completely enclosed and not being operated exposes one to an arc flash risk at all.