ARC Flash Protection

[BAHTAH]

My understanding is the basic requirement for both OSHA and NFPA makes it a violation of the law to work equipemnt hot. I was told there is a calculation required to determine boundaries in the area where hot work is done under the two exceptions that allow for working equipment hot. Does anyone know if this is, or will be in the NEC and if these calculations are made in the field by the electrician? Am I correct in the assumption that this will apply to all installations including residential?

 

[pierre]

Re: ARC Flash Protection

In the 2002 NEC, the requirement is for 'other than dwelling occupancies. OSHA and NFPA 70E are where you can find the info in detail for calculations- when needed and when not needed, and all the related good stuff which is too much detail for this post (poster).

Pierre

 

[ron]

Re: ARC Flash Protection

No code eliminates the possibility of working hot.

 

[brian john]

Re: ARC Flash Protection

Ron:

Is your statement made as in no speeding sign will stops speeders? If so your are right, but hopefully it will put contractors and management firms on notice of their legal liabilities

 

[BAHTAH]

Re: ARC Flash Protection

Ron, 110.16 Flash Protection supports Pierre's statements, what concerns me is the reference to NFPA 70E safety requirements and specifically that an overview of these requirements is not in the NEC. I think we can all agree systems will be worked hot, however NFPA 70E will have the lawyers lined up when someone works on these systems, gets injured and was unaware of the NFPA 70E requirements that are only mentioned as a FPN in the NEC. I do not have a copy of NFPA 70E but from what I have read from other sources it would appear it is a violation of law to work systems hot except for two circumstances (1) if deenergizing introduces increased hazard and (2) infeasible due to the need for testing the system while energized for diagnostics. In addition finanical considerations are not considered an adequate reason to work energized circuits and to violate these regulations is a violation of federal law punishable by fine and/or imprisonment. I hope I am not reading all of this correctly otherwise I will need a lawyer the next time I install a 20/1 breaker in a commerical panel. I am not saying we should not be safe, just wondering if NFPA 70 puts limitations on what circuits and systems can be worked on to the point where what we all considered standard proceedure in the past will soon be a violation of the law.

 

[ron]

Re: ARC Flash Protection

There is some judgement as to whether equipment must be worked hot. NFPA 70E says to wear the correct clothing. It does not say that you cannot work hot. The NEC says to place a sign saying to watch out (no calcs required from the NEC)!

NFPA 70E Part II
Chapter 3 Personal and Other Protective Equipment
3-1 General.
Employees working in areas where there are electrical hazards shall be provided with, and shall use, protective equipment that is designed and constructed for the specific part of the body to be protected and for the work to be performed.

3-2 Care of Equipment.
Protective equipment shall be maintained in a safe, reliable condition. The protective equipment shall be visually inspected before each use.

3-3 Personal Protective Equipment.
3-3.1 General.
When an employee is working within the flash protection boundary he/she shall wear protective clothing and other personal protective equipment in accordance with 2-1.3.3.3 of Part II.

[ November 06, 2003, 09:12 PM: Message edited by: ron ]

 

[don_resqcapt19]

Re: ARC Flash Protection

1910.333(a)
"General." Safety-related work practices shall be employed to prevent electric shock or other injuries resulting from either direct or indirect electrical contacts, when work is performed near or on equipment or circuits which are or may be energized. The specific safety-related work practices shall be consistent with the nature and extent of the associated electrical hazards.

1910.333(a)(1)

"Deenergized parts." Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations. Live parts that operate at less than 50 volts to ground need not be deenergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs.

Note 1: Examples of increased or additional hazards include interruption of life support equipment, deactivation of emergency alarm systems, shutdown of hazardous location ventilation equipment, or removal of illumination for an area.

Note 2: Examples of work that may be performed on or near energized circuit parts because of infeasibility due to equipment design or operational limitations include testing of electric circuits that can only be performed with the circuit energized and work on circuits that form an integral part of a continuous industrial process in a chemical plant that would otherwise need to be completely shut down in order to permit work on one circuit or piece of equipment.