ANSI/NETA MTS REQUIRED? 2

[HuskyFC450]

The manufacturing facility where I am employed as an electrician has never had an "Electrical Hazard Assessment, Arc Flash Analysis/Survey, or any ANSI/NETA MTS tesing performed on any of it's electrical distribution or protective relay equipment. Most (if not all) of the electrical equipment and Molded Case CB's have been in place for 25 years without even being exercised. There has never been an Electrical Maintenance Program since this company was first formed. I have been adamant in my pursuit to have the company bring in a NETA-certifed contractor to perform verification tests on all of the OCPD's, but they seem to be taking the stance of "well, we,ve never needed this before...why now?" One of my concerns is this: They have contacted their insurance group to find an EE(PE) that has experience with Arc Flash Analysis and Surveys. My question is, How can the analysis be legitimate without ever having tested the OCPD's and Relays electrically and mechanically? It's widely an accepted fact within industry that MCB's over 5-years of service will fail to operate correctly 15% of the time, or operate at a much slower speed the first time they are tripped. This significantly increases the incident energy exposure in an Arc Flash scenario. Is this common industry practice to have an Arc Flash Survey performed without ever testing the equipment? Can a company be NFPA-70E compliant without EVER having NETA-certified testing of said electrical equipment?

 

[dpc]

I think you are basically correct. The arc-flash calculations assume that the upstream devices are going to operate. Whoever does the arc-flash study should recommend maintenance testing of the protective devices as part of their report. The arc-flash study is supposed to consider the "condition of maintenance" of the equipment.

Whether the testing must be NETA compliant is another issue. There is no specific requirement that NETA standards or NETA-certified contractors be used for maintenance testing, although that is certainly the main organization in the US that deals with testing of electrical equipment. But there are a lot of competent testing organizations, including groups associated with manufacturers that are not NETA members.

 

[HuskyFC450]

Thank you dpc.

Is there any language in NFPA 70E, IEEE 1584 or OSHA that requires employers to electrically and/or mechanically "test" their OCPD's?

Tom

 

[dpc]

You might have a look in NFPA 70B. I believe you can view that at no cost at nfpa.org

 

[HuskyFC450]

Will do. Thanks for the tip!

Tom

 

[oldfieldguy]

I'm looking at similar issues. I manage the electrical side of things for thirty-odd natural gas compression facilities, many of which have 480-volt equipment dating back to the early 1950's.

I know the part about NFPA 70E's requirements regarding arc-flash studies. I have been working on them.

The scary part, though, is that I have been in the electrical testing biz since 1989 and had a NETA Level IV certification before changing to the present job. The 15% failure rate for molded-case breakers is, in my personal experience, pretty close to the truth.

Hover, much of MY equipment is bolted in place. Having dealt with this before, it is my experience that the simple act of removing a molded-case breaker for testing, then replacing it in its original location is a high-risk exposure in that many connections will not be restored properly. When you add to that the electrical risk, where you know you're going to have to work on live equipment and you're going to see sizable electrical outages because by nature the breakers you're interested in testing will be critical feeders, I see NFPA 70E as offering more hazards than it corrects. That's just an opinion, you understand. I'm working on this.

Another issue: Cost. If you're around a major industrial area, testing companies, both NETA and otherwise, may be available. Outside those areas, you're going to be paying for expenses and mileage in addition to personnel cost and test equipment cost. Having been in this business, that runs up a bill pretty fast.

Lastly, and this pains me to say, a lot of the 'test technicians' who perform this work may not be as capable as wed like them to be. I know. I hired and evaluated a lot of them. I also followed them, correcting some of the issues created, including more than a few here connections to power circuit breakers were not properly made up following 'maintenance'. Believe me, "NETA" in a company descriptor or on a card does NOT confer a real feeling of comfort to me. It's only as good as the technician on YOUR job.

I am changing our engineering standards to require future installations to employ drawout power breakers for major loads, but we use many smaller power panels and switchracks and those feeder breakers will need to be tested to validate their condition for arc-flash.

I'm interested in seeing other thoughts.


old field guy

 

[catserveng]

I have to agree with many of the points brought up by "old field guy", I also worked for a NETA company for a few years, the supervising engineer was the reason I joined the company, a joy to work with, but when he left it wasn't so much anymore.

I have a customer in my area struggling with many of the same issues described in the post, there are several molded case breakers, larger frames with very compact buswork installation that on a few occasions has resulted in problems after testing. Hard to reach bolts in areas of poor access done by people trying to hurry working an odd hour shift certainly seems to increase the potential for problems, add to that that unfortunately some people working in the industry, at least in my recent experience, don't seem as diligent as I thought we were in the past. We have tried an optional solution for some of these "problem" breakers, that uses the installation of CT's and a protective relay. Initially the cost seemed high and definitely not an across the board solution for the problems we seem to encounter with molded case breakers, but when we looked at difficult installations, breaker types that appeared to have failure rates higher than the 15% stated above, poor access for test equipment (yeah, the breaker test stuff is big and HEAVY), and the critical nature of the load being fed, all of the sudden the cost of CT's and a relay and the one time install cost seemed to make sense in some of those applications.

Some added features helped sell the idea to their management, like better fault recording, ability to use relay data for metering, ability to test (if a test switch installed) with minimal service disruption, and ability to easily change settings for service access (arc flash settings). Some were pretty hard opposed to the idea, some greatly in favor, and from a long term standpoint I guess we'll see as we only started doing this a year ago.

I had tried a similar situation many years ago to address reliability problems with local generator breakers in rental equipment. The units going over the road many times a year resulted in a huge number of failures, both nuisance trips and failure to trip. Cost of repair, maintenance and the occasional additional costs due to downtime of failure of customer equipment was eating away at an already small margin. Disabling the trip unit and turning the local breaker into a switch controlled by a protective relay was a good solution in that situation. As cost and dropped and features/capabilities of new relays has improved, maybe in some cases it could be an effective alternative solution. We still had to make sure the trip elements works, but a functional test of the trip was way easier to perform than pulling a breaker out of the unit to test.

Still go into a lot of facilities where regular testing and maintenance is not being done, some figure a label warning of arc flash hazard is enough and it is the electricians problem to figure it out. As long as you don't have a meltdown or an accident you might get away with it. In my area several years ago one of the large insurers was very proactive about making sure their customers did the right thing, now days they wait until they get a claim, then one of the first things they ask is if you've done your recommended maintenance, no records, no claim.

Great post! Mike L

 

[Zogzog]

First off, regarding NETA testing companies, I agree 100% with OFG's comments, spot on.

Second, the current edition of the NFPA 70E states:

130.5 Arc Flash Hazard Analysis
The arc flash hazard analysis shall take into consideration the design of the overcurrent protective device and its opening time, including its condition of maintenance.

Informational Note No. 1: Improper or inadequate maintenance can result in increased opening time of the overcurrent protective device, thus increasing the incident energy.

Informational Note No. 4: For additional direction for performing maintenance on overcurrent protective devices, see Chapter 2, Safety-Related Maintenance Requirements.

205.3 General Maintenance Requirements. Overcurrent protective devices shall be maintained in accordance with the manufacturers’ instructions or industry consensus standards standards. Maintenance, tests, and inspections shall be documented.

Informational Note: Refer to NFPA 70B, Recommended Practice for Electrical Equipment Maintenance, and ANSI/NETA MTS-2007, Standard for Maintenance Testing Specifications for Electrical Power Distribution Equipment and Systems, for guidance on maintenance frequency, methods, and tests.


The 2015 edition fo the NFPA 70E is going to make some major changes regarding this subject, futher details of maintenence requirements and the vadility of the arc flash study. Also the will be seperate task tables with different HRC's for properly maintained equipment.

However, here is the issue with NETA tests, they require the breaker to be opened and removed from service to test trip times, which does not represent a real world condition. Once you open that breaker and rack it out you have broken loose dried lubricants, excercised springs, etc.. what you really want to validate the assumptions used for the arc flash study is first trip data. There are many ways to catpure this data, this device is new and perhaps the most simple way to do it.

http://www.circuitbreakeranalyzer.com/breaker-first-trip-testing.htm

 

[oldfieldguy]

Zogzog-

I first used a first-trip device when working with a large southern utility company. It is a very good tool, and I recommended it to several clients after I went back into power system field services. The unit I used collected an operating current profile of the trip sequence, measuring operating time from the trip current/voltage spike and contact interruption time from CT inputs. It did indeed point out some issues with transmission and distribution breakers.

It did not tell me the condition of system protection devices and their ability to sense and properly react to overcurrent conditions.

As I said before, a large part of my issue is with medium and large (2000 amp frame) molded case circuit breakers, some of which have relatively new integral solid state trip devices. Others have the electro-thermo-mechanical devices. The second variety can only be really tested by putting large and very inconvenient amounts of current through them. Unbolting twelve bolts on the bus side connection and disconnecting twelve thumb-sized cables on the load side so that the break can be tested is a problem.

Can it be done? Yes. Of course. Is the testing valid? Yes, for the most part. Does it cost? You betcha. I have to bring in a contractor with a test set that is towed in on a trailer. He may have to travel with said trailer for several hundred miles to my site in Armpit, Mississippi, for which I pay, and when he gets there, he's pulling out the ONLY breaker feeding my station, so I'm off-line on an interstate pipeline, for a scheduled outage, all the while hoping that something doesn't get broken by that remove-test-replace cycle.

Ah, the prospects of retirement...

old field guy

 

[Zogzog]

That's why you never want to spec large frame breakers as bolt in (Fixed)

And yes, while this new generation of analyzers are much easier to use than what you used before they are for mechanical condition assesment of the breakers and do not replace ANSI/NETA type electrical tests. Perfect tool for validation of an arc flash study though.

 

[stevenal]

The system will measure the first movement and capture the peak amplitude of the contacts parting and stopping. From that data we can determine whether the first trip time is within manufacturer's specification.

So please understand this relates only to the contact parting time. Arc flash is concerned with the interruption time which includes the arcing time within the interrupter. Without validating that arcing time also remains acceptable, I fail to see how the arc flash study can be validated.

 

[jraef]

There is however a larger over arching issue at play: there are no NFPA 70E police. People who resist having to deal with this will be quick to point out that there is no law forcing compliance with NFPA 70E, as there is for instance with NFPA 70, aka the NEC.

The fallacy however is that there IS in fact a law that says you must provide a safe workplace, and very SPECIFICALLY a safe ELECTRICAL work environment; Federal Standard 29 CFR 1910, Subpart S, the "OSHA Electrical Safety Standards". It is administered and enforced by OSHA, who are frequently described as "toothless dogs" that are all bark and no bite, but here's the catch. OSHA will typically only get involved IF there has already been an accident. So if that happens, question #1 from the OSHA inspector is "What is the nature of your electrical safety program?" If your response is "We have a program that follows the NFPA 70E guidelines", then your conversations are more technical and factual from that point on.

If on the other hand your response is "Well, we've never needed this before...why now?" then the conversation not only takes a negative turn, but, and this is the part that most management people fail to understand, it can take a CRIMINAL turn. In addition to the entire workplace being shut down immediately, plant managers and even SUPERVISORS who fail to implement and enforce a program of electrical safety of some sort that meets accepted industry standards (such as NFPA 70E) can be fined and JAILED for failure to comply.

Have them put that in their pipe and smoke it...

"Will work for (the memory of) salami"