Use of table without verification.

I was talking with an engineer from a medium size manufacturer today. They have about 200 employees. They want to start an arc flash program based upon the Task Table but have a problem. They are an old facility without a good one-line. They don't have the internal resources or the cash to hire a contractor to do the work for them.

My suggestion to them was to just begin their program using the Table, even if they can't verify the footnotes. I figure better something now rather than wait another 6 to 12 months, and the Table has a reasonably good chance of being acceptable anyway. Later when resources become available they can complete the technical evaluation.

What is your opinion on this. Would you wait until you could do it right, even if it meant waiting another year, or would you just start with the Table in the hopes that its at least 90% correct.


This is the real world where businesses are fighting to just survive. They no longer have the resources, either in people or money, to do all that is expected.

Due diligence

Jim brings out a good point that something needs to be done. What drives me crazy about the Table Method is that no task is ever Dangerous yet almost every main disconnect tied to the secondary of the plant's main transformer comes back with over 40 cal/cm2 in an engineered study.

Some due diligence can always be done:
1. Contact the utility for fault current info (no cost but takes longer to get than people expect)
2. Get all affected personnel at least in 100% cotton uniforms, a class 4 PPE kit for the main swithchgear room(s) and some class 2 PPE kits to start.
3. Break the plant into smaller projects so that cost can come from a Maint. or Operating budget rather than capital appropriation (MV system only, single line effort only, start with one transformer at a time, etc...)

The point is to make incremental progress the right way rather than spending time/resources developing a Table method plan which always seems to raise more questions than it answers.

Good advice FEC2, thats the way to get er done. You can also do a quick verification of the tables limits, no real study needed right away, just someone that knows what they are doing can determine right away if the tables can be used.

True story, I was getting ready to do some 70E training at a hospital in the midwest and they had decided not to do a study and just use the tables. When I asked the safety manager and EE about being within the limits they said they assumed they were and just to tell the guys it was OK to use the tables. I offered the plant a free quick analysis to see if at least thier main subs were within the limits (3000kVA transformers, no INST on mains) and they declined, they got mad at me and said I was assuming they could not use the tables, I said no, I am offering to verify that for you and you are assuming you can use the tables. They told me (I still can't believe the head of safety said this), worse case, if something happens, we have a burn unit here at the hospital, just tell them it is OK or we will find someone else to do the training. I got up, said good luck, and left.

Well someone else did do the training but I didn't want anything to do with it.

Training

Before I do any on site training ( switching and arc-flash ). I perform a safety audit , then I request a meeting with the plant EE's, Safety Officer, Facility Manager (s).

If they are way out of compliance I inform them that the first thing you are going to get hit with is a bill for $20k worth of safety equipment and the subsequent follow up maintenance (Gloves etc.). Money for an Arc flash study would be great, but you have to walk before you can run.

If they are not prepared to spend it .....I walk.

I have found , if presented correctly , and proved that it is to there benefit (not mine)to have it done correctly . Most comply. I think ignorance of the OSHA regs is the root problem.

Couldn't agree more Capt. Thats the danger of the training providers that just come do the training. Many times they catch the company off gaurd and after the training the employees refuse to work because they dont have the PPE, equipment, and safety procedures in place. I always tell customers to meet with the trainer before the training to address these issues.

Some of the trainin out there is so bad that all that dosen't matter, they don't know anything more after the training then they did before the training, besides seeing some scary videos. Some of the programs out there are very sad.

Electrical Safety in Hosptials with Burn Units

Zog. The first arc flash incident I was involved in investigating was in one of Louisville's downtown hospitals with a burn unit.

Electricians in a hurry to start stuck a wooden measurement with a metal tip into 13.8kV and arced. The one on the ladder measuring was DOA. The other guy was taken to the burn unit and died in 5 days. Not much consolation. I would rather KNOW I don't meet the tables and start on partial studies than ignore the issue thinking that would make me look better in a lawsuit.