Liquid Tape: An acceptable repair for damaged 480V wire?

[Jon456]

As promised, here's the next chapter in the story of our beleaguered wire pulls...

As first described in this post last year, and then discussed again in this post this year (see "Problem 1"), our #4 250kW solar inverter had tripped its 400A breaker in our PV distribution panel several times in the past. I had long suspected that the 500MCM CU-XHHW-2 inverter branch circuit conductors (which, btw, I had incorrectly referred to as "inverter feeders" in past posts) were damaged, but the problem was intermittent and the installation contractor was never able to trace the fault, largely due to the fact that he was too cheap to own a megger.

When we had our facility's main feeders (installed by the same contractor) blow-up earlier this year, we had all the solar AC wires meggered by an independent testing company. They confirmed that one of the wires to our #4 inverter had leakage. This was the set of conductors that the contractor pulled the wrong way through an LB as illustrated in this photo:

I had watched them pull these wires in during the original installation and knew at the time that the insulation had to have been damaged as they used a tractor to pull -- with great strain -- the final loop of those large wires in through that LB. So I was not surprised by the results of the testing agency and I told the property owner and the installation contractor where I thought the wire damage was located, namely between the LB and the inverter. My recommendation was that the inverter be removed from the pad and the conduit be disassembled back to the LB. The damaged wire could have been cut out and the LB could have been replaced with a weatherproof wireway to contain the splices for the repairs.

So imagine my surprise when the contractor reported repairing the wire after having the inverter offline for only 45 minutes! This was his "repair" on our 480V/400A wires:

LB Left Entry:

LB Back Entry:

That's right: he opened the LB and brushed some Liquid Tape on the wires and then used some peeled-off LFMC outer jacket material to sleeve his repairs! I suspect the LFMC jacket is providing more dielectric strength than the thin layer of dried Liquid Tape.

I can't believe this is an acceptable repair. But I need some solid NEC or UL references to back up my argument. Advice please!

 

[mgookin]

I think the wire manufacturer is your best source for that.

But let's see what the pros on here chime in with...

 

[Sierrasparky]

I suppose it might be ok if useld as per the manufactures spec. Not that it would do it or condone it.


EEEKS

My 2 cents ... Your company paid for a complete, new, properly installed installation. i would think this is not.

 

[don_resqcapt19]

If I was the owner, I would not accept any repairs to the conductors. I would require the contractor to replace the conductors with new ones.

I tend to doubt that the LB meets the requirements of 314.28 and if it doesn't he would have to replace that too.

I don't think that there is anything in the NEC that directly addresses the issue of insulation repair of anything other than flexible cords (400.9). The closest rule is probably 110.14(B) for conductor splices.

110.14(B) Splices. Conductors shall be spliced or joined with splicing devices identified for the use or by brazing, welding, or soldering with a fusible metal or alloy. Soldered splices shall first be spliced or joined so as to be mechanically and electrically secure without solder and then be soldered. All splices and joints and the free ends of conductors shall be covered with an insulation equivalent to that of the conductors or with an identified insulating device. Wire connectors or splicing means installed on conductors for direct burial shall be listed for such use.

 

[xformer]

If I was the owner, I would not accept any repairs to the conductors. I would require the contractor to replace the conductors with new ones.

I tend to doubt that the LB meets the requirements of 314.28 and if it doesn't he would have to replace that too.

I don't think that there is anything in the NEC that directly addresses the issue of insulation repair of anything other than flexible cords (400.9). The closest rule is probably 110.14(B) for conductor splices.

I concur with Don

 

[zbang]

The EC gets points for originality but then loses them all for being a bonehead. And I highly suspect that if asked about insulation repair, the wire mfg will say "Don't".

Either way, it's a hack job.

 

[GoldDigger]

That restored the Megger reading, but without pulling the wires how can he be sure there is no other concealed damage that has reduced the insulation strength, just not to where the Megger notices it?

Tapatalk!

 

[Sierrasparky]

The EC gets points for originality but then loses them all for being a bonehead. And I highly suspect that if asked about insulation repair, the wire mfg will say "Don't".

Either way, it's a hack job.

No way would any manufacture allow such, agreed.

That restored the Megger reading, but without pulling the wires how can he be sure there is no other concealed damage that has reduced the insulation strength, just not to where the Megger notices it?

Tapatalk!

Agreed!

Why doesn't someone call the CSLB on this hack. It will shut him down.

 

[Jon456]

Why doesn't someone call the CSLB on this hack. It will shut him down.

We can't shut him down. We're only 1.5 years into his 10-year warranty on our installation (not that it's doing us much good).

 

[PetrosA]

We can't shut him down. We're only 1.5 years into his 10-year warranty on our installation (not that it's doing us much good).

It sounds like maybe it might be worth doing some calculations and determining whether or not it's worth spending the next 8.5 years of your life dealing with this yo-yo. From your threads so far you and your company have a lot of man-hours, scheduled and non scheduled down time as well as third party costs invested in dealing with this just in the first 18 months after the project was completed. How does the math project for the next few years?

If it were a vehicle you had purchased, at least you'd have lemon laws on your side

 

[K8MHZ]

We can't shut him down. We're only 1.5 years into his 10-year warranty on our installation (not that it's doing us much good).

I would be looking for the gnarliest lawyer I could find to get him off the job, remove all his work, have it re-done properly by a reputable firm and have Mr. Hackjob's bond cough up the money to pay for it all.

By the sounds of things, if you don't, someone else will, he will lose his bond and his license and that 10 year warranty will go up in smoke like the rest of the stuff. In fact, he may KNOW he won't be in business for long, so he can promise you a 100 year warranty and all he needs to do is glue and tape your job together long enough for him to vamoose.

 

[kwired]

Taking care during installation was an issue. Conduit body could even be too small for the application.

Outside of that I don't see any thing wrong with the use of the "liquid tape". If there are damages inside the raceway they will not be so simple to repair though.

When encountering direct bury conductors that have minor dings in the insulation I always coat them with 3M "Scotchkote". Kind of a similar thing, just no conduit body involved. That repair may even be better insulated then the conductor alone was - but only at that one spot.

 

[Jon456]

Taking care during installation was an issue.

The installation crews did not believe in taking any care during the installation. Their "recipe for success" on this job contained only two ingredients: brute force + "git 'er done" as quickly & cheaply as possible. Mind you that most of the wire pulls on the job were NOT performed by electricians (or even by guys with prior electrical experience). The contractor had one "senior" man on the job who basically acted like the foreman. He was a yahoo and a braggart who claimed to have worked for PG&E in the past, although I think he was just a heavy machinery operator. He certainly wasn't a licensed electrician. He was the kind of guy who did everything by the seat-of-his-pants. If they needed a sweep in the PVC conduit, he'd pour cement all over it, set it on fire, and bend it. If wire needed to be pulled, he'd rope it up and yank it through as hard as he could with whatever machine he had available: Gradall, loader, or backhoe. Wire lube, mandrels, swabs, cable grips, tuggers, sheaves, etc, were all superfluous and unnecessary in his book. The contractor did have two electricians and one electrician apprentice on his crew, but for most of the job they were on the roof tops stringing the solar panels and wiring the combiner boxes. All the rest of the crew were temporary construction laborers, many of whom were hired through a local "low-income community development" (i.e., affirmative action) program. The "foreman" and these temp hires were the ones doing the bulk of the wire pulls.

For this particular inverter pull, they pulled the wire in the wrong direction through the LB. For smaller wires, the direction of pull through an LB is less of an issue (for small wires like 6 AWG or less, it's not really an issue at all). But for 500MCM, the geometry of the wire loop feeding back into the LB really makes a difference. Furthermore, they did not use any wire lube (which was their SOP during the entire job). During the project, they were already well into this pull when I first approached to observe. They had doubled-up some 2,500 lb mule tape at least four times and tied it directly around the wire bundle (they never once used cable grips, pulling eyes, or swivels) and were pulling with a Bobcat as hard as they could. At the wire head, the insulation was practically stretched down to the copper by the time the mule tape snapped. So the wire must have been subjected to somewhere in the neighborhood of 10,000 lbs of pulling tension. I noticed that they were pulling "dry" and told them to put lube on the wires, which they finally did. On the second round, they were able to pull it in. But I strongly suspected at the time that they had damaged our wire.

Outside of that I don't see any thing wrong with the use of the "liquid tape". If there are damages inside the raceway they will not be so simple to repair though.

I would not be surprised at all to find much more damage beyond what is accessible via the open LB.

Outside of that I don't see any thing wrong with the use of the "liquid tape".

The only time I've ever used liquid tape is to weatherproof "vampire" connectors on low-voltage landscape lighting. Even when I glob it on, it dries to a very thin layer. On smooth flat surfaces, I doubt that a single layer is more than 10 mils thick. How can that compare with the dielectric strength and longevity of 65 mils of intact, factory-applied XHHW-2 insulation?

When encountering direct bury conductors that have minor dings in the insulation I always coat them with 3M "Scotchkote". Kind of a similar thing, just no conduit body involved. That repair may even be better insulated then the conductor alone was - but only at that one spot.

But encountering existing direct bury wire with minor dings in the insulation is not quite the same as someone incompetently and negligently installing new wire in conduit.

Also realize that the original plans were for the installation of THHN wire. Shortly after the contract was awarded, we chose to pay additional money to upgrade all the AC wire to XHHW-2 due to it's superior insulation performance in wet conditions. Our facility is located on reclaimed tidal mud flats and is below sea level, so our soil has a lot of salt content and the water table is literally just below the surface (we have some shallow pot holes in a dirt road that are filled with ground water year-round). So we wanted to spend the extra thousands of dollars to ensure the longevity of these wires. Would you accept these installed wires if you had paid for new?

 

[gadfly56]

The installation crews did not believe in taking any care during the installation. Their "recipe for success" on this job contained only two ingredients: brute force + "git 'er done" as quickly & cheaply as possible. Mind you that most of the wire pulls on the job were NOT performed by electricians (or even by guys with prior electrical experience). The contractor had one "senior" man on the job who basically acted like the foreman. He was a yahoo and a braggart who claimed to have worked for PG&E in the past, although I think he was just a heavy machinery operator. He certainly wasn't a licensed electrician. He was the kind of guy who did everything by the seat-of-his-pants. If they needed a sweep in the PVC conduit, he'd pour cement all over it, set it on fire, and bend it. If wire needed to be pulled, he'd rope it up and yank it through as hard as he could with whatever machine he had available: Gradall, loader, or backhoe. Wire lube, mandrels, swabs, cable grips, tuggers, sheaves, etc, were all superfluous and unnecessary in his book. The contractor did have two electricians and one electrician apprentice on his crew, but for most of the job they were on the roof tops stringing the solar panels and wiring the combiner boxes. All the rest of the crew were temporary construction laborers, many of whom were hired through a local "low-income community development" (i.e., affirmative action) program. The "foreman" and these temp hires were the ones doing the bulk of the wire pulls.

For this particular inverter pull, they pulled the wire in the wrong direction through the LB. For smaller wires, the direction of pull through an LB is less of an issue (for small wires like 6 AWG or less, it's not really an issue at all). But for 500MCM, the geometry of the wire loop feeding back into the LB really makes a difference. Furthermore, they did not use any wire lube (which was their SOP during the entire job). During the project, they were already well into this pull when I first approached to observe. They had doubled-up some 2,500 lb mule tape at least four times and tied it directly around the wire bundle (they never once used cable grips, pulling eyes, or swivels) and were pulling with a Bobcat as hard as they could. At the wire head, the insulation was practically stretched down to the copper by the time the mule tape snapped. So the wire must have been subjected to somewhere in the neighborhood of 10,000 lbs of pulling tension. I noticed that they were pulling "dry" and told them to put lube on the wires, which they finally did. On the second round, they were able to pull it in. But I strongly suspected at the time that they had damaged our wire.


I would not be surprised at all to find much more damage beyond what is accessible via the open LB.


The only time I've ever used liquid tape is to weatherproof "vampire" connectors on low-voltage landscape lighting. Even when I glob it on, it dries to a very thin layer. On smooth flat surfaces, I doubt that a single layer is more than 10 mils thick. How can that compare with the dielectric strength and longevity of 65 mils of intact, factory-applied XHHW-2 insulation?


But encountering existing direct bury wire with minor dings in the insulation is not quite the same as someone incompetently and negligently installing new wire in conduit.

Also realize that the original plans were for the installation of THHN wire. Shortly after the contract was awarded, we chose to pay additional money to upgrade all the AC wire to XHHW-2 due to it's superior insulation performance in wet conditions. Our facility is located on reclaimed tidal mud flats and is below sea level, so our soil has a lot of salt content and the water table is literally just below the surface (we have some shallow pot holes in a dirt road that are filled with ground water year-round). So we wanted to spend the extra thousands of dollars to ensure the longevity of these wires. Would you accept these installed wires if you had paid for new?

Too bad Mike Holmes doesn't do commercial work, he could turn your site into a mini-series.

 

[petersonra]

How is this any different than making the same repair with black tape?

As long as it is a safe repair, I have no issue with the repair itself, as long as the material used is intended to be used in this way.

I also have no problem with his choice of sleeve material. A sleeve is unnecessary IMO, but I have no issue with him doing it.

i think you would have a very hard time convincing a court that the work has to be redone because something damaged in the install was properly repaired (if it was properly repaired).

You might have a good case that there are code issues here that need addressing.

 

[John120/240]

The installation crews did not believe in taking any care during the installation. Their "recipe for success" on this job contained only two ingredients: brute force + "git 'er done" as quickly & cheaply as possible. Mind you that most of the wire pulls on the job were NOT performed by electricians (or even by guys with prior electrical experience). The contractor had one "senior" man on the job who basically acted like the foreman. He was a yahoo and a braggart who claimed to have worked for PG&E in the past, although I think he was just a heavy machinery operator. He certainly wasn't a licensed electrician. He was the kind of guy who did everything by the seat-of-his-pants. If they needed a sweep in the PVC conduit, he'd pour cement all over it, set it on fire, and bend it. If wire needed to be pulled, he'd rope it up and yank it through as hard as he could with whatever machine he had available: Gradall, loader, or backhoe. Wire lube, mandrels, swabs, cable grips, tuggers, sheaves, etc, were all superfluous and unnecessary in his book. The contractor did have two electricians and one electrician apprentice on his crew, but for most of the job they were on the roof tops stringing the solar panels and wiring the combiner boxes. All the rest of the crew were temporary construction laborers, many of whom were hired through a local "low-income community development" (i.e., affirmative action) program. The "foreman" and these temp hires were the ones doing the bulk of the wire pulls.

For this particular inverter pull, they pulled the wire in the wrong direction through the LB. For smaller wires, the direction of pull through an LB is less of an issue (for small wires like 6 AWG or less, it's not really an issue at all). But for 500MCM, the geometry of the wire loop feeding back into the LB really makes a difference. Furthermore, they did not use any wire lube (which was their SOP during the entire job). During the project, they were already well into this pull when I first approached to observe. They had doubled-up some 2,500 lb mule tape at least four times and tied it directly around the wire bundle (they never once used cable grips, pulling eyes, or swivels) and were pulling with a Bobcat as hard as they could. At the wire head, the insulation was practically stretched down to the copper by the time the mule tape snapped. So the wire must have been subjected to somewhere in the neighborhood of 10,000 lbs of pulling tension. I noticed that they were pulling "dry" and told them to put lube on the wires, which they finally did. On the second round, they were able to pull it in. But I strongly suspected at the time that they had damaged our wire.


I would not be surprised at all to find much more damage beyond what is accessible via the open LB.


The only time I've ever used liquid tape is to weatherproof "vampire" connectors on low-voltage landscape lighting. Even when I glob it on, it dries to a very thin layer. On smooth flat surfaces, I doubt that a single layer is more than 10 mils thick. How can that compare with the dielectric strength and longevity of 65 mils of intact, factory-applied XHHW-2 insulation?


But encountering existing direct bury wire with minor dings in the insulation is not quite the same as someone incompetently and negligently installing new wire in conduit.

Also realize that the original plans were for the installation of THHN wire. Shortly after the contract was awarded, we chose to pay additional money to upgrade all the AC wire to XHHW-2 due to it's superior insulation performance in wet conditions. Our facility is located on reclaimed tidal mud flats and is below sea level, so our soil has a lot of salt content and the water table is literally just below the surface (we have some shallow pot holes in a dirt road that are filled with ground water year-round). So we wanted to spend the extra thousands of dollars to ensure the longevity of these wires. Would you accept these installed wires if you had paid for new?

I do not have experience in jobs of this magnitude but before awarding the contract is there any background check done ? Letters of reference from previous customers stating satisfaction ? What prior experience does the contractor have on jobs of this complexity ? What is your bonding company's responsibility to verify that you have the cajones to complete this job ? Before engaging Git Er Done Electric shouldn't the customer perform a background check ?

I can think of one California contractor (one man band) that could have assembled the man power & tools to complete this job on time & budget.

 

[Jon456]

I do not have experience in jobs of this magnitude but before awarding the contract is there any background check done ? Letters of reference from previous customers stating satisfaction ? What prior experience does the contractor have on jobs of this complexity ?

Not surprisingly, this question has come up before regarding our project. Allow me to quote my answer from another thread:

Just to be clear, I was not the one who awarded this contract. In fact, I was not even involved in the planning phase of this project (otherwise, I would have caught a number of errors in the engineered plans); I was brought on at the time construction started.

The contractor is an electrical engineer and licensed electrician. He came well-recommended and his company already had a history of a number of large commercial jobs, including some state government contracts.

 

[zbang]

You might have a good case that there are code issues here that need addressing.

OK, it's a stretch, but how about:
110.12 Mechanical Execution of Work. Electrical equipment shall be installed in a neat and workmanlike manner.

FPN: Accepted industry practices are described in ANSI/NECA 1-2006, Standard Practices for Good Workmanship in Electrical Contracting, and other ANSI approved installation standards.
(quoting from 2008, that was handy)

Or, does the wire mfg specify/recommend lube or specific pulling practices? Granted, without out some documentation some of those would be hard to bring up.

 

[Jon456]

I find it hard to believe that this would satisfy any measure of "good workmanship." I do know that we paid tens of thousands of dollars just for the brand new copper wire with XHHW insulation and we expected it to be installed professionally without cuts and breaks in the insulation. Those expensive new wires are now bandaged up with liquid tape and scraps of plastic, not to mention the ridiculous number of splices that have now been put in our wires to correct for his shoddy work.

Altogether, I believe this contract was almost three-quarters of a million dollars.

 

[flatlander]

I find it hard to believe that this would satisfy any measure of "good workmanship." I do know that we paid tens of thousands of dollars just for the brand new copper wire with XHHW insulation and we expected it to be installed professionally without cuts and breaks in the insulation. Those expensive new wires are now bandaged up with liquid tape and scraps of plastic, not to mention the ridiculous number of splices that have now been put in our wires to correct for his shoddy work.

Altogether, I believe this contract was almost three-quarters of a million dollars.

I doubt there is a bond in place that will cover that amount.

I think you need to get rid of this Hack as some have stated.