Better Than New

Dear Learned Leaper,

Why would I use rejuvenation, when I can have new cable?

Cable Guy

Dear Cable Guy-

I suspect, Cable Guy, that you’re not a circuit owner. Do you work for one of the cable manufacturers? If you were a circuit owner, you would know that money does not grow on trees and rejuvenation is almost always considerably less capital intensive than wholesale replacement. The question would have had more merit had it been asked two decades ago when the first generation of rejuvenation technology was becoming commercially important. The anticipated life of the first generation of fluid in non-demanding applications was and remains about two decades. The generally anticipated life of post 1990-vintage cables is about four decades. The 2X difference in anticipated life complicated the economic analysis of the treat or replace question. Advanced technology from Novinium can provide the same four-decades of service life, so that issue is a relic of the 20^th Century.

How about post-injection reliability? In the January 31, 2012 issue of the Las Vegas Regional Journal, it was reported that NV Energy experiences about a 0.6% failure rate when it replaces cable. NV Energy reports that the older injection approach has about the same failure rate over a 12-year period. Utilizing Novinium’s state-of-the-art technology and the outstanding craftsmanship of our service delivery experts, our overall failure rate is less than 0.4%. That’s about 33% better than the failure rate of new cable. Novinium rejuvenation technology is better than new! But, here’s the really cool part, Novinium technology and delivery methodology continues to improve! In the graph nearby I am pointing at the beta value of our Crow-AMSAA analysis of all of the faults we have ever experienced treating millions of feet of cable on three continents. The value is 0.56. A value less than one indicates that the failure rate is decreasing – a one would mean that it is staying the same, and a value greater than one would indicate deteriorating reliability. To learn more about Crow-AMSAA, check out my August 11, 2011 post, “Crow.”

Novinium announced the passing of the “Better than new” milestone today. Click here to read the press release. We periodically post a transparent summary of our failure history at novinium.com/Lessons.aspx.

Better next year,

Thermo B. Frog

The Color of Capital

Dear Gregarious Green One,

My firm uses Ultrinium™ and Sustained Pressure Rejuvenation to treat cables after they fail. The ability to capitalize single section injection with Novinium technology means we can earn a regulated rate of return on the capital thus expended. I read your four-part blog, “The Color on Money” and was wondering if you could do a similar analysis to help us quantify the benefit of our approach.

Considering Capital in Colorado

Dear CCC-

I am pleased that you appreciated my “Color of Money” posts. Click on I, II, III, and IV to review that work. Many of the concepts in the “Color of Money” apply to the “Color of Capital.” In fact, Parts II and III are prerequisites if you need a primer on depreciation and the time value of money respectively.

The ability to capitalize single sections of injected cable is available only from Novinium. In FERCs (Federal Energy Regulatory Commission) Letter order dated January 18, 2000, John Delaware, the Chief Accountant, wrote to the petitioner, Georgia Power:

“You indicate that CableCURE is used to rehabilitate entire segments of your underground distribution system (e.g. entire residential subdivisions as opposed to individual runs of cable between two terminal points).”

The only way you can capitalize CableCURE is if the entire subdivision is rejuvenated. The letter order is attached to this post for the interested reader. Novinium’s technology has no such limitation. The Letter Order promulgated by FERC’s Chief Accountant on September 4, 2008 and associated submittal information removes that limitation and can be accessed by clicking here. All of the above discussion is also true for RUS-funded circuit owners. Click here is view the RUS order of April 3, 2009.

That takes care of the regulators; now the analysis. We will compare two cases. All of the inputs are shown on the worksheet nearby. Parenthetical references to the worksheet cell designations appear in the following text.

Case 1

The cable fails, is repaired and put back in service. In our model the user can indicate how many faults are tolerated before the cable is replaced, together with an estimate of the time between faults. For this example, we assume the cable will fault twice over a two year period before it is replaced. The capital cost to replace is a modest $33.00/ft (Cell B7) and the O&M cost of a fault is $13.72/ft (Cell D13) in today’s dollars. That’s $4,500 (Cell B11 + Cell B12) divided by as assumed segment length of 328 ft (Cell B13).

Case 2

The cable fails, is repaired and injected in a single integrated operation. In our model the bundled unit capital is $20.06/ft (Cell D23). The model user can change any of the costs inputs and an assumption of the post-treatment reliability. For this example, the post-treatment failure rate is assumed to be 2% (Cell B26), which is about twice Novinium’s actual post-failure experience of about 1%.  To put this 1% failure rate in perspective consider that it is three-times higher than Novinium’s non-post-failure experience of about 0.34%. This higher-than-typical post-treatment failure rate is inherent in post-failure treatment. The post-injection fault is assumed to occur two years (Cell B27) after injection. Again the model user can adjust any of these assumptions.

Other Assumptions

Warranty remittances of $10/ft (Cell B23) are negative capital expenditures, that is, the remittances are subtracted from the subsequent replacement capital. Upon post-injection failure, the book value is written off, terminating the ratemaking-allowed return and providing a lump sum tax benefit of the book value. Cash flows are calculated for two rehabilitation cycles, up to 100 years. This approach allows residual values to be properly ignored as de minimis. Finally, replacement is assumed to have a zero-percent failure rate. At least one major investor owned utility has reported that new installations suffer a 0.6% “infant mortality” failure rate, and hence this assumption results in a slight understatement of the incremental value of Novinium^® post-failure rejuvenation.

Bottom Line

The cumulative net present values (NPVs) for the two cases are plotted nearby. Since the revenue or sale of electricity is the same in all cases, those revenues are ignored and only capital and O&M costs are depicted. This cost-only analysis is why all of the NPV values are negative. Nonetheless, the higher the cumulative NPV value is on the graph, the more advantageous to the circuit owner.

The blue line is for Case 1, and in the short run it is the superior choice. The problem is that once a cable begins to fail, it will re-fail. Sooner or later the ratepayers will be very upset with deteriorating reliability. Capital inefficient replacement is executed after the second fault (Cell B14) and the NPV plummets.

The orange line is for Case 2, and it represents an investment in reliability. The initial cost is about twice as great, but because the investment is capital, the circuit owner begins to earn a regulated rate of return. In the end, the incremental NPV advantage of Novinium post-failure rejuvenation is $18.42/ft. If your replacement cost is higher, say $44/ft, the difference becomes $21.15/ft. If in Case 1, the cable is allowed to fault a total of three times, the difference rises to $24.56/ft. Even if the cable is replaced after a single fault, the best alternative to rejuvenation, rejuvenation still enjoys an $11.45/ft advantage.

If you would like to run this model on your specific circumstances and execute “what if” scenarios, contact us at novinium.com/Contac.aspx.

Always conserving capital,

T. B. Frog

70-20120322_FERC_Letter_of_Approval.pdf (78.87 kb)

P1816

Dear Thermo,

What is this swanky “reliability” event that Novinium is sponsoring on the Seattle waterfront in conjunction with the ICC meeting on March 26, 2012?

News in Jersey

Dear Jersey-

First I wish to object to prejudiced policy promulgated by local health authorities. Amphibians are prohibited from attending the March 26^th event to which you refer. Not that I would have any interest in the menu, I won’t eat anything unless it is still moving. The human proclivity to eat long-dead stuff is abhorrent. Forget the food; denying me access to the content is what frustrates my flippers.

IEEE P1816™ is a soon-to-be-approved, “Guide for Preparation Techniques of Extruded Dielectric, Shielded Cable Rated 2.5 kV through 46 kV and the Installation of Mating Accessories.” P1816 starts where most accessory installation instructions end. It defines the best practices for accessory installation that will lead to the highest level of reliability. The P1816 Guide was assembled by circuit owners, component manufacturers, and reliability masters like my Novinium colleagues. On March 26^th, humans who have a stake in reliability will gather to kick-off a multi-part series of webinars that will delve into the details of high-reliability craftsmanship.

Regular attendees of the Insulated Conductors Committee (ICC) will recognize the speaker’s names as authorities on the subject of reliability. Vern Buckholz, an expert on neutral corrosion, Glenn Luzzi of Richards Manufacturing, and expert on cable accessories of all types, Harry Orton an expert on sources of reliability problems, Mike Smalley of WE Energies, a P1816 Co-chair, and Bill Taylor of 3M, an expert on splices and terminations, are just some of the proficient people who will be introducing the topic and setting the stage for a year of informative webinars designed specifically to spread the gospel of reliable craftsmanship. The webinars will be designed for the craft-folk that largely determine the post installation reliability of underground cable components. Management and engineers should plan on attending too, because there will be revelations for all.

Select attendees will also be given access to Novinium’s state-of-the-art eLearning “Cable Prep Course” based upon P1816 at knovinium.com and a companion field guide. If you have not been invited to this invitation-only event, contact your Novinium sales professional at novinium.com/Contact.aspx. To see the agenda click here.

Unable to attend myself, but there in spirit,

T. B. Frog

The Color of Money – Part IV

In my post of February 27^th, The Color of Money – Part I, I gave the big picture answer to Cap’s query. In February 28^th’s follow-up post we delved into the details of depreciation. On my Leap Day post we deliberated discounting. Today, in the fourth and last post of the series, we will tie up loose ends and cover the rest of the assumptions.

Rejuvenation Technology Inputs

In cells B12, B13 and B14, the name for “Product X”, the fully absorbed cost for product X, and the warranty length are entered respectively. Cells B16, B17 and B18, hold the same values for “Product Y.” Cell B20 is the ratio of the warranty length of Product Y divided by the warranty length of Product X.  The accounting lives are assumed to be the respective warranty lives.  The actual life multiplier in cell B21 is the ratio of the actual life of Product Y divided by the actual life of Product X. The warranty life is an approximate indicator of the actual life, as the technology suppliers use some combination of experience, accelerated life experiments, and accelerated life simulations to arrive at reliable life expectations.

For individual large and stable firms, such as most utilities, the spread or difference between the discount factor in cell B3 and the inflation rate in cell B6 is quite constant. If inflation increases, discount factors increase too. The 5.9% spread in the example is typical for the power distribution industry in North America.

Accounting Treatment of Warranty Remittance 

GAAP would suggest that warranty remittances are handled as negative capital expenditures. That is, the cost of replacement is reduced by the amount of the warranty remittance. Any remaining undepreciated value associated with rejuvenation is written off in the year of the failure on both the tax books and the rate-making books. Individual circuit owners may treat these warranty refunds differently. Write to me to tell me how your firm accounts for these warranty payments.  I’ll enhance the model to accommodate your method.

Residual Value

For any net present value analysis there has to be an assumption regarding the handling of residual values at the end of the analysis period. Where two rejuvenation technologies with different actual lives are compared, the technology with the longer life will have a greater residual value than the product with lesser life. For the purposes of this analysis a single replacement cycle is executed after the rejuvenation cycle has completed and future value is calculated to a one century horizon. Cash flows after 100 years are ignored. This assumption favors the technology with the shorter life, since the product with the longer life would have the greater residual value.

Bottom Line

This rigorous analysis confirms and quantifies what should be self evident. The longer the life – the greater the value.

Greener is better,

Thermonuclear Frog 

Real World V – Irrefutable Proof

In my last post of 2011, Wondering in Western Washington, questioned the merit of the claims made by UTILX^® in a document titled, “Life Extension Estimate for UtilX^® CableCURE^® Rejuvenation Fluid.”  That 17 page document includes numerous assertions that I examined in previous posts, Real World I, II, III, and IV. In this last in the series of five posts, I examine the veracity of the “irrefutable proof” asserted by the document’s author. Claims of “irrefutable proof” are actually quite easy to disprove. Even if there is a single decent argument that runs contrary to the assertion, the irrefutable proof rings hollow. This lowly frog cites five …

1.    If the proof is irrefutable, why would the author declare the analysis to be proprietary and confidential and sue his own customer to prevent its disclosure? UTILX did not prevail in its legal action. See UTILX v. City of Tacoma, No. 11-2-11594-7 in the Superior Court of the State of Washington in and for the County of Pierce. Click here and search on the case number to access court documents.

2.    The author failed to disclose that his first of three “real world” examples was treated unconventionally. The cable was treated from the inside-out as is in the normal case, but the cable was also treated from the outside-in. This deceptive tactic would not be used by someone with irrefutable proof. This Duke Deception lies outside the norm by about 240X!

3.    In the second of three examples presented, the author uses the Dominion Dodge, which lies outside the norm by a factor of between 20X and 150X.

4.    Why not provide data from a case or cases that are representative of typical “real world” cables? The author has access to a study performed by Florida Power and Light (FPL) that contradicts his assertions. Why does he fail to disclose that data? The FPL study was conducted in cooperation with the author’s firm. The FPL study was described semi-publically to NEETRAC members participating in a process to design a new side-by-side experiment to compare the post-injection performance of the commercially significant technologies. UTILX participated in the experimental design, but withdrew from the study when it was ready to begin, citing “business and commercial reasons.”  If UTILX’s technology is irrefutably better than that offered by Novinium, why would UTILX withdraw? NEETRAC, NEETRAC members, and Novinium completed the study.

5.    The author has access to the entire post-injection failure history of his firm. Why not simply publish this realest of “real world” data? Novinium publishes its full failure experience. Click here to view Novinium’s “Lessons Learned.”

Veritatem dies aperit (from Lucius Seneca, Time discovers truth)

T. B. Frog

Failure Causes III

In my January 24^th post, “Failure Causes I,” I provided a partial answer to an inquiry from Colorado Querier. Colorado sought to understand if rejuvenation technology was appropriate for the “many types of aging factors” from which his firm’s circuits might suffer. We learned that 39% or more of all circuit failures are component failures and that these reliability issues are directly addressed with a rejuvenation program.  In yesterday’s post, “Failure Causes II,” we learned that more than 78% of the cable failures, which represent over 60% of the circuit failures are directly caused by water trees.  78% times 60% yields 47%. Water trees are the root cause of more than 47% of circuit reliability issues. Taken together (39% plus 47%) component issues and water trees account for more than 86% of all circuit reliability issues. We could stop right there, because 86% could be characterized as the vast majority. We could stop right there, because of the over 100,000,000 feet of cable rejuvenated over the last two-and-a-half decades, over 99% continue to provide reliable service. Cables treated by Novinium enjoy a post-injection failure rate less than half that of the industry-wide figure. We could stop there, but we won’t. The Novinium masters of reliability strive for post-rehabilitation reliability perfection.

If component issues and water trees represent the frog’s share of reliability root causes, what are the secondary issues? And how does rejuvenation technology address, or not address, these issues?

Neutral Corrosion

The occurrence of neutral corrosion within the population of bare neutral cables is 100%.  But don’t despair, the occurrence of neutral corrosion that creates safety or reliability issues is an order of magnitude less significant than circuit failures from all other causes – that is, generally 1-2% of cables suffer substantive neutral issues. Click here to check out my July 7, 2010 post along with its links to other published works. Even though the neutral corrosion issue is less significant than many assume, the good news is that neutral corrosion is both detectable and addressable. In fact, the Novinium masters routinely detect and repair neutral corrosion.

Thermal Issues

When cables are heavily loaded over sustained periods the insulation loses anti-oxidants and plasticizers. Oxidative degradation and polymer embrittlement contribute to a decrease in dielectric strength and in severe, but rare, cases may lead to cracking of the insulation. Designed to stay in the insulation for decades after injection, Novinium’s Ultrinium™ 73X fluids include anti-oxidants (AOs) and plasticizers. These materials all but halt oxidative degradation and embrittlement. Anti-oxidants have also been proven to slow the rate of water tree growth and increase the inception voltage of electrical trees. Click here to learn more about anti-oxidants in my March 14, 2011 post, “AO, AO … It’s home from work we go.” If the insulation gets hot enough the conductor may migrate and the insulation will become eccentric. These eccentricities usually manifest themselves at tight bending radii. The Novinium masters identify and remove most excessively bent cable sections. These most commonly occur near terminations or accessible splices and these areas are inspected during pre-injection preparation. Novinium^® brand rejuvenation addresses all of these thermal issues.

Halo

Halos are unavoidable when a cable is thermally cycled in the presence of water. Thermal cycling creates micro-voids in the middle radius of the insulation driven by the “Molecular Thermodynamics of Water in Direct-Buried Power Cables.” Click here to view the paper by the same name from IEEE Electrical Insulation Magazine (Nov/Dec 2006). The collection of voids formed this way is referred to as a halo. In the absence of water trees or some other defects, a halo does not lead to failure, because the halo size is limited by the molecular thermodynamics of water in the polymer. None-the-less, rejuvenation reverses most of the dielectric degradation caused by halos by filling the micro-voids with more compatible organo-silicones. Novinium^® brand rejuvenation addresses halos.

Manufacturing Defects

Voids, protrusions, contaminants, eccentricities, and skipped shields are “unwanted features” of a new cable. With the possible exception of skipped shields all of these unwanted features are in every cable. Fortunately for your newer purchases the magnitude of the defects is low enough that the cable can provide reliable service for its design life. For both your new cable purchases and your 30- and 40-year-old legacy purchases if the defects are large enough the cables will fail early in their lives … these kinds of defects yield what statisticians call infant mortality.  Your decade-old cables have been screened by operation of substantive manufacturing defects – those that will actually cause a failure without an accompanying water tree. In short, manufacturing defects are everywhere, but in legacy cable their manifestation is a water tree growing from the defect. Rejuvenation directly address the water tree and Novinium Ultrinium™ 73X brand rejuvenation includes patented stress grading components, which directly address stress-enhancing defects. Click the links below to learn more about stress grading …

Installation Defects

Excessively tight bending radius, excessive pull force, and exterior abuse rendered during installation are analogous to manufacturing defects. Serious problems manifest themselves shortly after installation. If an installation defect survived for several decades it is not so serious that it cannot be addressed by rejuvenation technology, particularly technology that includes Novinium patented stress grading chemistry.

Physical Damage (post-installation)

Frost thrust, dig-ins, and critter attacks can occur at any time. At Novinium we have seen insect attacks and rodent attacks. Amphibians have never been a problem. In the case of critter attacks, these usually occur near terminations and hence are often discovered and rectified as a routine matter during a rejuvenation program.  Dig-ins and frost thrust are generally not discoverable, but follow a pattern similar to manufacturing and installation defects. Cables struck with significant damage fail shortly after the event, insignificant damage may be mitigated by rejuvenation. In summary, rejuvenation mitigates, but does not prevent all failures resulting from post-installation physical damage. Rejuvenation with stress grading technology such as that found in patented Novinium Ultrinium™ 73X brand rejuvenation fluids provides superior mitigation.

Testing Induced

My faithful readers know that this frog is not a devotee of diagnostic testing. The fundamental problem can be summed up thusly:  None of the technologies can reliably discriminate between cables which will fail in short order and those which will not. The rejuvenation program alternative puts a final nail in the diagnostic coffin, because components will all be changed anyway. What sense does it make to find out if the components are good or bad? Since over 99% of rejuvenated cables don’t fail when no diagnostics are utilized and the extension of life is 5-20 times longer that the retesting horizon, paying for a diagnostic is difficult to justify.  If all of that were not enough many diagnostics test induce defects! Electrical trees can be initiated directly by high voltage methods such as off-line partial discharge or indirectly by inducing space charge with DC methods. Even though it makes no technical sense to test, rejuvenation does mitigate the damage testing inflicts on cables if rejuvenation is given some time to improve the dielectric performance of the cable.  For SPR that is about a week; for UPR it is best to wait for at least a year. To explore diagnostic testing further do a key word search on my blog for “diagnostic testing.”

Insulation Shield Separation

Loss of adhesion between the insulation shield and the insulation is a rare occurrence and is the only fault mode not addressed or at least mitigated by rejuvenation. This frog can count on one front paw, and I only have four toes on that paw, the number of failures where the loss of insulation shield adhesion was the cause of failure. These few observed failures suggest that chemical contamination of the soil causes swelling of the shield material and loss of adhesion. Transformer oil or motor oil spills are suspected culprits. If you have a bunch of these kinds of failures on your hands, you have a potential Love Canal situation and you are going to be excavating the whole neighborhood.  No need to treat the cable.

Summary

Advanced cable rejuvenation provided by the masters at Novinium has a proven track record of 99.4% post-rejuvenation reliability. Almost all known causes of solid dielectric underground cable reliability problems are either directly addressed or mitigated. The sole exception is insulation shield separation, which is incredibly rare.

Broad Spectrum Reliability,

T. Bull Frog

Failure Causes II

In yesterday’s post, “Failure Causes I,” I provided a partial answer to an inquiry from Colorado Querier. Colorado sought to understand if rejuvenation technology was appropriate for the “many types of aging factors” from which his firm’s circuits might suffer. In yesterday’s post we dealt with circuit failures caused by connected components, rather than the cable itself. Today we will focus on cable failures.  First a disclaimer – it is often difficult to determine with 100% certainty the cause of a cable failure in field conditions. A cable failure is a destructive event that usually vaporizes its own root cause. Those who analyze field failures can examine the cable near its fault for neighboring defects. If a defect or defects are found, the examiner may infer without certainty that a similar defect may have been the root cause of the actual fault. If no substantial defects are found the root cause will surely remain unknowable.

I emphasized “substantial” in the last sentence because at a small enough scale there are always defects. Water trees grow in all medium voltage solid dielectric cables exposed to moist conditions. Unless you have hermetically sealed metal sheaths, those would be your cables! Water treeing is an oxidative process, but even where there are no water trees, oxidation of the polymer occurs, because oxygen and other oxidizing agents are ubiquitous. Free radicals facilitate oxidation and are common in nature. Cosmic radiation, radioactive decay, and other natural processes spawn free radicals around the clock. On top of those chemical processes there are mechanical strains placed on the cable by thermal cycling driven by load cycling.  Such thermal cycling creates micro-voids in the middle radius of the insulation driven by the “Molecular Thermodynamics of Water in Direct-Buried Power Cables.” Click here to view the paper by the same name from IEEE Electrical Insulation Magazine (Nov/Dec 2006). The collection of voids formed this way are referred to as a halo.  I provide an illustration of a halo and water tree nearby.

What are the primary causes of failure and how is each addressed or not addressed by rejuvenation?

In the frogograph nearby, I show you a subset of field reliability data (Editors note: I have come to call this kind of data – “real, real world!”) gathered by Dr. Steennis of KEMA. The simple logarithmic equation explains 78% of the relationship between maximum water tree length, expressed as a percentage of the insulation thickness and reliability expressed as AC breakdown strength.  AC breakdown strength is not a perfect surrogate for cable reliability, but it’s a pretty good one!  Lightning bolts appear next to each cable sample that failed in service. Water tree length is the single best predictor of reliability. In the same work, Dr. Steennis and his colleagues demonstrated that the laboratory failure of the field aged cables always occurred at the longest water tree, just as a chain fails at its weakest link.

Well over three-quarters of solid dielectric cable failures are caused by water trees. Rejuvenation technology was originally designed to address water tree degradation specifically. In fact, rejuvenation has a proven track record of treating the biggest and ugliest water trees on the planet.  Click here, to check out my October 5, 2011 post, “Water Trees – Too Big to Fail?” In my third post of this series we will examine the other less important root causes of cable failure and consider whether or not those root causes can or cannot be addressed by the application of rejuvenation technology.

Master of Reliability,

T. Bull Frog

Failure Causes I

Dear Beautiful Bull Frog-

I wonder if you have any information I could use to help address a concern I have heard in my company.  That concern is that a 30 to 40 year old cable may have accumulated degradation due to many types of aging factors. Cable injection may not substantially address these factors and injection may not provide a very great increase of life extension for a very old cable.

Colorado Querier

Thank you for the inquiry Colorado. That is actually a great inquiry, because it will take me more than a single post to answer! The first question we have to address is:  Which of the two categories of failures plague your solid dielectric circuits?  In the figure nearby I ponder this question, because only you can know? At Jicable 2007, the International Conference on Insulated Power Cables, Nigel Hampton of NEETRAC (National Electric Energy Testing Research and Applications Center) provided some survey data from their circuit owner members in a paper titled, “Validating cable diagnostic tests.”  Perceived failure experience of NEETRAC member companies suggested that on average, 55% of the failures in the population are cable failures, 39% are accessory failures, and 6% are unknown.  The perception of Utility 21 is that almost all of its failures are cable failures and very few of its failures are accessories. The perception of Utility 4 is reversed.  Utility 4 perceives that about 4 out of 5 of its failures are component failures and 20% or less are cable failures.

If the primary cause of your failures are components, consider which components are failing – terminations or splices or both. There are two injection paradigms, namely Unsustained Pressure Rejuvenation (UPR) and Sustained Pressure Rejuvenation (SPR). See “How to Inject” for more on UPR and SPR. Novinium is the only firm in the world that can use both paradigms. UPR attempts to flow through existing splices, so it is not the best choice if your firm experiences splice reliability issues. SPR replaces 100% of the splices and terminations with modern state-of-the-art components. UPR replaced all of the dead-front terminations, so if those are problematic components for you, UPR will address that issue. Novinium has made several improvements to the safety and reliability of dead-front terminations used for injection. I will describe those improvements another day.

In summary, if your reliability issues are primarily component issues, rejuvenation directly addressed these with systematic component replacement. Depending upon your specific circumstances, the Novinium masters of reliability will help you decide which injection paradigm best addresses your reliability issues at the lowest capital cost.

If your reliability issues are cable-centric, check out my next post in this series, Failure Causes II, where we will ask the question:  What are the primary causes of cable failure and how is each addressed or not addressed by rejuvenation?

Master of Reliability,

Thermo Bull Frog

EPR (Part 1 of 3)

Dear Grandest of Frogs,

I was in the audience of an ICC (Insulated Conductor’s Committee) discussion group C30 (Extending the Life of Field Cables) and was confused by the discussion about treating EPR cables. There were some in the room who seemed to be of the opinion that rejuvenating EPR cables is not appropriate.  Does it ever make sense to rejuvenate EPR cables?

Regards,

Ethel P. Reliability

Dear E.P.R.-

I was not at the meeting in question, but I have several very good friends who were, so I got the straight scoop.  First there was a bizarre suggestion that those who originally invented rejuvenation technology never intended to treat EPR cable.  Two gentlemen who were actually there for the original inventive step of modern alkoxy-silane-based rejuvenation technology were founders of Novinium and are able to confirm that claim is without merit.  The target of the development effort was solid-dielectric cables – EPR cables fall within that genre.  There were several very vocal proponents of EPR cable at that meeting and they were united in a common narrative.  To wit, EPR cables do not fail, they do not suffer water treeing, and hence rejuvenation is counterproductive.

Poppycock!  Poppycock!  Poppycock! Let’s take those assertions one at a time.

EPR cables do not fail

EPR cables do fail.  One laboratory (Cable Technology Laboratory or CTL) that studies cable failures on a routine basis reports that over three decades they have received about 600 samples of failed XLPE cable and about 10 samples of failed EPR cables.  At first glance, one might say that this anecdote suggest a 60-fold reliability advantage for EPR cables over XLPE – that assumption would be exagerated, because about four-times more XLPE cable was deployed from 1964 to 1980 (See Forrest, “Predicting Medium Voltage Underground Power Cable Failures and Replacement Costs,” Western Electric Power Institute, Apr. 8, 1997).  What would be fair to say is that over the course of the last three decades, the reliability of 1960-1980 vintage EPR was about 10 to 15 times better than the same vintages of XLPE cables.  Historically more reliable, yes … invulnerable, no … in need of rehabilitation at some point, yes.

EPR cables do not suffer water treeing

It is true that imaging water trees in EPR cables is quite challenging. EPR cables are filled with clay and as a consequence even very thin samples are opaque.  Traditional microscopic examination with staining often fails to reveal water trees.  A colleague at CTL has figured out a way to image trees in EPR.  Bogdan Frysczyn’s annotated images nearby show bow-tie and vented water trees right at the failure breakdown channels in so-called “pink” EPR.  Similar images have been made for brown and black EPR too.  So much for that narrative.

Rejuvenation of EPR would be counterproductive

Now that we have established that EPR cables do fail and that they suffer the same water treeing phenomenon as XLPE cables, it would seem to be self-evident that rejuvenation would benefit aging EPR cables.  Over a  decade ago, my friends over at CTL together with EPRI (Electric Power Research Institute) and Reliant Energy (Houston) wrote a paper demonstrating just this entitled, “Extending the Service Life of Ethylene Propylene Rubber Insulated Cables.”  In this paper, the authors concluded:

• It is feasible to upgrade early vintage black EPR cable and achieve a significant increase in ac and impulse voltage breakdowns.
• It is feasible to upgrade current vintage pink EPR cable and achieve a significant increase in ac and impulse voltage breakdowns.

These results were based on treatment with phenylmethyldimethoxysilane (PMDMS), which is the primary ingredient in both CableCURE^®/XL fluid offered by UTILX^® Corporation and Perficio™ 011 fluid provided by the Masters of Reliability™ at Novinium. In two subsequent posts, this frog will explain another misconception perpetrated at the last ICC meeting (EPR 2 of 3) and how the technology has advanced over the last decade to improve the post-injection reliability of EPR cables specifically (EPR 3 of 3).

Eternally Proactively Reliable,

Thermonuclear B. Frog