puckman
Senior Member
- Location
- ridgewood, n.j.
if there isn't a arc flash program in place is there another way to handle the safety issue and still be in complience with osher and nfpa
arc flash
- Thread starter puckman
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zog
Senior Member
- Location
- Charlotte, NC
Define "arc flash program"
frizbeedog
Senior Member
- Location
- Oregon
Arc Flash is a program I don't want to view. 
However, there are electrical saftey policies that are implemented by contractors to be in compliance with OSHA requirements for safe electrical work practices.
Perhaps you could expand on what you wish to know.
:smile:
However, there are electrical saftey policies that are implemented by contractors to be in compliance with OSHA requirements for safe electrical work practices.
Perhaps you could expand on what you wish to know.
:smile:
frizbeedog
Senior Member
- Location
- Oregon
According to NFPA 70E/2009, 300 volt and below less are not required to have arc flash analysis equipment fed from transformers rated 125kva and performed. What are the labeling requirements? NEC 110.16? But does that not require a label indicating that "an arc flash hazard exists"? If you put that label on should you not establish hazard parameters and PPE requirements?
zog
Senior Member
- Location
- Charlotte, NC
that is in the 1584, not the 70E and it is less than 240V not 300V
that is the generic requirement but 70E requires more than that, wither the PPE required or the Ei needs to be on the label.
thats the requirement
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
NFPA70E-2009 130.3 Exception No. 1 says :
An arc flash hazard analysis shall not be required where all of the following conditions exist:
(1) The circuit is rated 240 volts or less.
(2) The circuit is supplied by one transformer.
(3) The transformer supplying the circuit is rated less than 125 kVA.
(2) The circuit is supplied by one transformer.
(3) The transformer supplying the circuit is rated less than 125 kVA.
NFPA 70E has tables that can be used instead of calculating the incident energy, if certain fault current magnitude and interrupting time criteria are met.
You can make the calculations by hand without a computer program. You can purchase IEEE Std 1584 which includes an Excel program for calculating incident energy and arc flash hazard boundaries.
You can make the calculations by hand without a computer program. You can purchase IEEE Std 1584 which includes an Excel program for calculating incident energy and arc flash hazard boundaries.
Where do you draw the line?
Where do you draw the line?
I will only refer to the ARC flash portion of the hazard evaluation.
I too have been grappling with the same question. We contracted to perform an Arc Flash study to comply with the 70E requirements. We just completed the study a month ago and are starting to apply the recommendations of the study.
We ran into this same question. If the devices are rated such that meet exception #1 of section 130.3, then accordingly, they should not need to be evaluated, correct? That means either by analysis or by the tables. I have read the 70E document several times and have found nothing to answer this question. The Appendix F in the back is nice but they also state these appendix are not part of the requirements of the NFPA document so they are for information only. The Appendix F also does not touch on the exception in question.
I believe that there should be a label applied to indicate that there is no flash hazard analysis necessary and therefore no ARC flash PPE would be required to work inside these devices. Normal shock hazard boundaries and PPE would still apply. We currently label all those devices as an Arc flash category ?0? which requires the persons working in them to have on the appropriate PPE.
Can anybody add any clarity to this issue?
Where do you draw the line?
I will only refer to the ARC flash portion of the hazard evaluation.
I too have been grappling with the same question. We contracted to perform an Arc Flash study to comply with the 70E requirements. We just completed the study a month ago and are starting to apply the recommendations of the study.
We ran into this same question. If the devices are rated such that meet exception #1 of section 130.3, then accordingly, they should not need to be evaluated, correct? That means either by analysis or by the tables. I have read the 70E document several times and have found nothing to answer this question. The Appendix F in the back is nice but they also state these appendix are not part of the requirements of the NFPA document so they are for information only. The Appendix F also does not touch on the exception in question.
I believe that there should be a label applied to indicate that there is no flash hazard analysis necessary and therefore no ARC flash PPE would be required to work inside these devices. Normal shock hazard boundaries and PPE would still apply. We currently label all those devices as an Arc flash category ?0? which requires the persons working in them to have on the appropriate PPE.
Can anybody add any clarity to this issue?
richxtlc
Senior Member
- Location
- Tampa Florida
You can analyze the circuit and if the Ei is <1.2 cal/cm2 then the HRC=0 and you can wear just cotton work clothes. But, as a note, we have done analysis on systems rated <240, 125 kva, etc and found that an arc-flash hazard does exist due the the tripping current falling into the slow trip portion of the curve for the circuit breaker. It's always a good idea to add it in to the calcs to see where you stand.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
!30.3 exception 1, says an analysis is not required, it does not say PPE is not required.
My interpretation is if you do not perform an analysis the equipment still needs to be labeled as HRC=0.
The argument for this exception has to do with the possible inability of 240V to sustain an arcing fault with an appreciable amount of incident energy. This is where the theory of calculations conflicts with the real world experience.
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