IEEE 1584 Update
I wanted to provide an update of the IEEE P1584 working group meeting that was held last month. As many of you know, I am a member of this working group and attempt to keep everyone in the loop of what is happening. Some things I am not at liberty to discuss yet, but here is an update of what I can pass along.
Legal – I hate to do this but I have to remind and warn everyone that this post is just an informal update of what I’ve seen and heard in the committee meetings. This information
can not be used to guide you on any studies, analysis or investigation. You’ll have to wait for the “official standard” to be published.
Testing Progress
Testing is underway. The collaborative group that was formed between NFPA and IEEE spent a year developing the test protocols (this group is different than IEEE P1584). The first tests were finally begun in January. Tests will be conducted at 4 different labs (I’ll keep the lab names anonymous for now).
No test information from the collaborative group has been released to the IEEE P1584 group yet. It is thought it might be another year or two. As many of you have heard from me before, research by committee moves at the speed of a glacier. This is why I try to keep everyone updated with what ever information I can pass along. Testing of pressure, bus bar orientation (yes horizontal and vertical bus arrangements can give you different results), DC, barriers, and much more. I understand DC testing has been completed but nothing is public yet.
There is a 200 page test plan that includes going up through medium. The test plan is held by the collaborative group and not public. Testing above that level will not be performed by either the collaborative group or IEEE P1584. This will likely fall to the Electric Power Research Institute (EPRI) as discussed in earlier posts.
The collaborative group was attempting to raise 6.5 million dollars and so far has raised 3.7 million. If your company wants to participate as a project sponsor, let me know and I’ll put you in contact with the appropriate people.
[email protected]
The unexpected:
Just to illustrate how tests can produce unexpected results, one test produced some high incident energy values. Then a dummy was placed in front of the same test configuration. The dummy caused the blast to deflect back to the arc source and extinguish the arc lowering the total incident energy. Hmmm, to lower the incident energy, stand directly in front of the arc flash?? (just kidding!)
Correction to NFPA 70E 130.3 Exception 1:
I checked with one of my colleagues from the NFPA 70E committee about this new addition. There has been much discussion about the statement:
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.
Etc….
IEEE 1584 uses the language “less than 240 volts” NFPA’s version was a mistake and should likely read “less than 240 volts” not “240 volts or less” The intent was 120/208V and not inclusive of 240V.
I mentioned this elsewhere in the Arc Flash Forum already. I have not seen this in any addendum yet.
“Interacting With Equipment”There was a bit of discussion about the word “interacting” as in the NFPA 70E definition of Arc Flash Hazard that includes the wording “interacting with the equipment in such a manner that could cause an electric arc.”
This has caused a bit of heart burn with people and a few of the members of this forum have been doing a good job of pointing this out. Unfortunately, there is not a very clear description of what is intended. The article referrers to Table 130.7(C)(9) for examples of activities that could pose an arc flash hazard.
130.7(C)(9) states: “in most cases closed doors do not provide enough protection to eliminate the need for PPE for instances where the state of the equipment is known to readily change.”
What I heard in discussions is this was intended to apply to larger equipment with significant incident energy and not intended for smaller equipment with low I.E. The problem is no direction has been given on what is large and what is small. I think it’s pretty obvious switchgear breakers fall into this category but what is a reasonable cut off for smaller equipment? Sounds like for now it will continue to rely on the calculated incident energy and lots of judgment.
The Arc Flash Forum continues to be a good place to compare notes on everyone’s thoughts and views about this.
IEEE 1584.1 Update
I am co-Chairman of this task group (which is different than IEEE 1584 without the “dot one”) and this proposed new document is intended to be a guide for specifying an arc flash calculation study in accordance with IEEE 1584 practices. We are still working on revisions to the draft and fitting in everyone’s comments and concerns. The hope is to provide a guide to help in the specification of more uniform arc flash studies. The concern is the scope of arc flash studies is all over the map and owners that do not know what they should be receiving can be (and are being) taken advantage of.
We are working on this document during the spring and summer and the IEEE P1584 working group will meet again this fall. I’ll give everyone another update then.
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