Cable injection technology 7

[kingstone]

Hi guys:
I am working at a power company ,Recently there is a company who claimed by injecting a silicone-based fluid to the crosslinked polyethylene?XLPE?cables?15-25kV? can guarantee extended the life of XLPE cables to at least 20 years.
?1?Is there anybody has experience about this treatment and is true or not it can extended the life of XLPE cables to at least 20 years?
?2?Are there any risks about this treatment?
thanks

 

[davidbeach]

I didn't know that XLPE had an expected lifetime of less than 20 years. Are you talking about filled strand aluminum cable, where there is a substance, may or may not be silicone-based, filling the voids between the strands of the aluminum conductor as an additional protection for the aluminum conductor? That is applied at the factory, I doubt anything could be injected after the fact and provide any benefit.

 

[jraef]

My local PoCo, PG&E in Northern California, bought in to that concept some years back. BIG failure. Did absolutely nothing towards life extension. I have an underground xfmr on my property and the primary cable exploded under my sidewalk a few years ago, so they had to destroy a big chunk of my front yard in the repair. Being in "the industry", I had several chats with the site engineers from PG&E about this subject. They said that PG&E sued the supplier, but they had decalred bankruptcy shortly after getting paid for their work, then started up again somewhere else under a different name. Sounds like maybe they found you.

The upshot was that the "fluid" never really penetrated much beyond about 1-1/2 feet from the pressure connector. Some of them also theorized that the high pressure process that was supposed to force this fluid into the cable may have caused voids and micro-cracks in the insulation, actually hastening the failure. They found out it became a really common occurrrance that the cable failed 5-6 feet away from the injection point. That's actually what got me talking to them. The workers just started tearing up my driveway at one spot about 5-6 feet from the transformer vault. I asked them how they knew where the fault was, they pointed to the engineer and he filled me in on the story. He knew by experience where the cable would have failed and he was right! As he put it, the whole program was basically a scam.

Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[SphincterBoy]

A big THANK YOU to jraef for the heads up.

We were contemplating buying this (Cablecure) recently, and the only thing we heard about it was "success" stories from the sales rep. I knew it sounded too good to be true.

We've been installing EPR insulated cables (133%) for ten years now, as XLPE has a much shorter lifetime ([per former AEIC board member), and have had no failures of these cables.

 

[jghrist]

This process has been around for at least ten years and Cablecure is still in business. Before rejecting it based on anecdotal evidence from a forum, I'd check with some users directly first. Also see:

http://tdworld.com/mag/power_partnership_strives_eliminate/index.html

http://tdworld.com/mag/power_srp_enhances_reliability/index.html

http://tdworld.com/news/power_army_discovers_inexpensive/index.html

http://tdworld.com/mag/power_submarine_cable_rescued/index.html

I researched this in the early 90's for a project in Saudi Arabia, but did not recommend it for economic reasons (cable in conduit, so replacement was more economic). I have no direct experience with the product - I just know it has been around for quite a while.

 

[stevenal]

We've used it. Cable is in service about five years later. I understand an impressive amount of water exited the cable before the silicone came through.

Davidbeach,

The original XLPE cables were not strand filled and had problems with water treeing. I'm not sure of the life span, but almost any life extension pays for itself since most of these installations are direct buried.

 

[benlanz]

The process of cable injection has worked quite well for stranded URD PE based cable (incl. HMW, XLPE) as proven by over 20 years of experience by the UTILIX corporation and Florida Power and Light. Most of the problems with injection in the USA and abroad have been related to large conductor feeder cables. We have been told that the technology has been improved for feeder cables but, we have yet to see statistically significant evidence. At this time we only recommend injection for URD cables. Our recommendation may change as new data is presented.

Two caveats:

Injection only mitigates water tree problems.
Injection can not correct electrical tree problems. Water trees do not fail cable. They spawn electrical tree which cause the cable to fail. The best way to find electrical tree is to perform a power frequency PD diagnostic stress test to locate and remove them. You may want to consider a PD diagnostic stress test to clean out the electrical tree before injection. Given enough time and the right system conditions, electrical trees will go to failure with or without injection. Injection typically accelerates electrical tree growth and the failures typically occur in the first few months after injection. (IEEE Insulation Research 2006 June/July)

Concentric wire neutral corrosion:
Injecting a cable can mitigate water tree problems and warranty the insulation of URD cable but, it can not slow the corrosion of your unjacketed cable. What is the value of a warranty if the cable will not have a concentric neutral in a few years? (IEEE ICC Cable Reliability Discussion Group Minutes Spring 2006)


Benjamin Lanz
Vice Chair of IEEE 400
Sr. Application Engineer
IMCORP- Power Cable Reliability Consultants

 

[Seven32]

The comments of Ben Lanz are generally accurate. There is a newer and better injection process that was introduced in February 2006. Check out the company's website at

http://www.novinium.com.

The folks at Novinium are the same folks that invented the first generation of technology about two decades ago. The old stuff works as Mr. Lanz said, the newest technology works much better. The life rivals that of new cable.

 

[ScottyUK]

Seven32,

I guess from your handle that you are either an employee or salesman for Novinium products. It is a common courtesy to disclose such information when recommending your own products.

Ben,

Interesting comments as usual.


----------------------------------

I don't suffer from insanity. I enjoy it...

 

[Seven32]

Thanks to ScottyUK for the heads up. My last post was my first visit to this web site. My name is Glen Bertini and I hold over 15 patents in the field of cable life extension. I invented the technology which has been employed on over 75 million feet of cable at over 300 utilities on 4 continents and saved approximately $1B in replacement costs over the last two decades. My new company, Novinium, has 8 patents pending on technology which significantly improves upon my older, but very sucessful technology.
Mr. Lanz's statement that water trees do not cause cables to fail, electrical trees cause cable to fail, is a bit like a tobacco company still suggesting that smoking does not cause death, heart disease or lung cancer cause death. While the proximate cause of the failure is indeed electrical trees, water trees are the root cause. There is absolutely no evidence in any peer reviewed work which even suggests that partial discharges can be detected in water trees. Electrical trees in insulation do proceed each failure, but they are exceedingly rare (because they are so short lived) except where they are induced by testing of the sort promoted by Mr. Lanz. The second suggestion regarding neutral corrosion is a bit misleading too. See

http://www.utilx.com/pdfs/Neutral_C...corrosion&pr=library&order=r&cq=&id=44bf544f4

for a thourough discussion of the insignificance of neutral corrosion and the ease of its diagnois.
The bottom line to the kingstone question is that silicone injection has over 20 years of sucessful commercilization on a massive scale and while there are certainly cases where the technology might not be appropriate it has a proven track record of great success.

 

[apowerengr]

I've worked for three different utilites which all tried the injection technology and all had success stories associated with it - given the right set of circumstances. I'd suggest you outline your particulars site conditions and ask for some references for projects of a similar nature.

Best case I had was in 1994 - 1964 vintage XLPE, 2 mile shot. Cable lasted another 10 years without failing but was ultimately replaced as the backup cable failed four times (1974 vintage black EPR). Worked with Mr. Bertini on that particular project and was pleased with the result.