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

[Jon456]

and after you've collected his bond, and sued him, and there isn't any money,
you can deduct it as a bad debt at tax time, and write it off.


and until he settles with his bond company, he's out of business. nobody will bond him, and i bet he doesn't have $10k to self bond. folks with duct tape and goop don't have spare change, usually.

When we were forced to replace the aluminum main feeders to our facility (which this contractor damaged), we chose to install (8) 400 MCM copper instead of (16) 500 MCM aluminum (derating our service from 1,000A to 600A). We agreed to pay the difference between the 2,880 feet of copper, and the 5,760 feet of aluminum for which the contractor was liable. The cost difference was $10,218. The contractor demanded we pay him up-front for this upgrade but we refused. So we are still holding that money which is owed to him.

Additionally, our property owner generously offered to pay half the cost of the generator rental for keeping our facility powered while those damaged feeders were being replaced. The contractor should have been on the hook for the whole cost, but the owner wanted to make a goodwill offer to provide an incentive for the contractor to perform the work safely (see my other thread about "Pulling wire through 480V energized panels."). IMO this was an unnecessary concession. Why should we have paid for the contractor to do the job correctly and in compliance with OSHA standards? And it's not like the contractor was grateful and worked to ensure we were satisfied with his repairs. He's been fighting us every step of the way, even complaining about our wanting to megger test the newly pulled wires and trying to prevent us from doing so. In any case, we still are holding those funds too. I don't know what that rental cost was, but I'm guessing our share may have been about $1,000.

So at least we are holding ~$11,000 of money we owe him. That won't stop him from suing us if we use those funds for completing the repairs. But it's better than us paying wholly out-of-pocket and then trying to sue him to recoup our losses.

As for him, he has money and assets, although his personal assets (house, etc.) are likely shielded by his LLC.

 

[Jon456]

Just out of curiosity, do you know what direction the original pull was made in for these wires?

Yes. Look at the red arrows in the photos in my first post. Read the narrative in my first post too. In short, the LB was installed in the wrong orientation for the direction they wanted to pull the wire.

 

[GoldDigger]

Yes. Look at the red arrows in the photos in my first post. Read the narrative in my first post too. In short, the LB was installed in the wrong orientation for the direction they wanted to pull the wire.

Got it. Yes, very good chance of more scraped areas inside the 30' pipe, but at least you can be more confident in accepting good Megger readings for the rest of the run.

 

[Jon456]

Got it. Yes, very good chance of more scraped areas inside the 30' pipe, but at least you can be more confident in accepting good Megger readings for the rest of the run.

Unfortunately, not necessarily true. I base that on the number of other conductors that were damaged in what should have been fairly easy pulls.

 

[Fulthrotl]

So at least we are holding ~$11,000 of money we owe him. That won't stop him from suing us if we use those funds for completing the repairs. But it's better than us paying wholly out-of-pocket and then trying to sue him to recoup our losses.

As for him, he has money and assets, although his personal assets (house, etc.) are likely shielded by his LLC.

$11k is a good start, add the $1k of dead copper you pull out, and it might just be a push.
a 3R gutter, some hypress and cold shrink, and some wire.

the other half of the run is the wild card, however. don't suppose the conduit is large enough
to allow substituting aluminum simpull with hypress and cold shrinks on the end, is it? if it were,
and you could substitute aluminum for the copper, there is enough value in the scrap copper
to pay for the whole kit and kaboodle.

i'm currently looking into pulling out 4 sets of 3 conductor 500 mcm copper and replacing with aluminum.
the value of the copper exceeds the cost of the whole thing by a fair bit.

 

[Jon456]

Update.

As the threat of litigation looms, the contractor has stated that, as a "gesture of good faith," he will "remove the LB and install a pull box in the same location and splice the existing wires in that same location." We responded that, at a minimum, we require the 30 feet of wire from the existing LB to the inverter inspected for insulation damage. The reasons our demand are as follows:

1. I personally witnessed the installation of these wires and observed the problems they had getting the wires pulled in the "wrong way" through the LB. The 500 MCM copper wires had to make a U-turn out of the LB and back in, followed by an immediate short-radius 90 deg bend to feed into the conduit to the inverter. At that 90 deg bend, the wire was being pulled across the metal edge of the LB. Unfortunately, I didn't take photos at the time. But these mock-up photos illustrate what happened:​

First photo shows the geometry of the wires and the direction of the pull (yellow arrow) towards the inverter:

Second photo shows how the wire had to make a very tight turn to get into the conduit to the inverter:

Third photo shows where the wire was jamming against the inside edge of the LB as they pulled:

Realize that the mock-up photos above only show a single wire for clarity. He was pulling in three 500 MCM copper wires. Also note that they were not using any wire lube (until I told them to do so), they were pulling with a Bobcat tractor, and they snapped the pull line (possibly exceeding 10,000 lbs of tension). In my professional estimation, there is no chance of those wires having suffered zero damage to the insulation along that 30 foot length.

2. We know there was some damage caused by the pull through that LB, because it failed a megger test prior to the contractor's liquid tape and scrap plastic repair, and now it passes.

3. We know that the 400A breaker tripped 3 times a year ago. The amperage rating on a breaker is for continuous excessive-current draw over a period of time; it actually takes a much higher current flow to instantaneously trip a breaker, typically 5x the breaker?s rating. So the fault that tripped the breaker was likely over 2,000A. If the arc occurred in the areas where the contractor applied the Liquid Tape (at the inlet and outlet of the LB), we should be able to see significant physical evidence of damage caused by the arcing: burnt metal, melted insulation, black soot, etc. None of that was visible when I inspected the inside of that LB. I suspect that the damage that caused those faults lies further inside the metal conduit, between the LB and the inverter. The likely reason it stopped faulting (and the reason it passed the Megger test) is because, by the third time it arced, enough of the metal was vaporized to create an air gap too large for the voltage to jump. The megger tests are being performed with 1,000 VDC and the breakdown voltage of air is ~1,000V/mm. So as long as there exists an air gap of greater than 1mm at any point where the wire is damaged, the megger will not reveal that damage.​

So here is his response to our request to have that 30 feet of wire exposed and visually inspected:

The May 7 repair to Inverter #4 on phase C of the 500MCM wire at the LB, by inverter #4 was made after inspection of the wire in this area did not indicate scrapes or wire exposure. Liquid electrical tape was applied to various areas inside LB and in addition, wire sheathing was added to protect edges. Post repair megger tests indicated all inverter #4 wires at maximum level with no leakage. It is clear that the LB was the area of minimal leakage since megger tests, post repair, resulted in no leakage. While tests demonstrate that the patch resolved wire leakage and the repair successful, we offered to install a pull box at the LB location.

On July 15, I revisited the lines at inverter #4 and megger tests show all lines at maximum value (photos below). Lines are in excellent working condition and should remain active. Inspection of the conduit between the inverter and LB showed it is in good condition without signs of damage. The metal conduit is properly grounded (see photo below) and provides a grounding body for insulation leakage detection (megger testing) along its length.

You claim that the repair on inverter #4 wire is completely unacceptable, that it fails electrical code and exposes us to gross negligence. Please provide the code reference and how the repair does not meet that code to substantiate your claims. Your demand to remove 30' of wire between the LB & inverter to investigate damage is without basis. If there were an issue with the wire, it would be detected through megger tests. Pulling out wire may result not only in damage to the wire but to the fittings as well.

 

[kwired]

Update.

As the threat of litigation looms, the contractor has stated that, as a "gesture of good faith," he will "remove the LB and install a pull box in the same location and splice the existing wires in that same location." We responded that, at a minimum, we require the 30 feet of wire from the existing LB to the inverter inspected for insulation damage. The reasons our demand are as follows:

1. I personally witnessed the installation of these wires and observed the problems they had getting the wires pulled in the "wrong way" through the LB. The 500 MCM copper wires had to make a U-turn out of the LB and back in, followed by an immediate short-radius 90 deg bend to feed into the conduit to the inverter. At that 90 deg bend, the wire was being pulled across the metal edge of the LB. Unfortunately, I didn't take photos at the time. But these mock-up photos illustrate what happened:​

First photo shows the geometry of the wires and the direction of the pull (yellow arrow) towards the inverter:

Second photo shows how the wire had to make a very tight turn to get into the conduit to the inverter:

Third photo shows where the wire was jamming against the inside edge of the LB as they pulled:

Realize that the mock-up photos above only show a single wire for clarity. He was pulling in three 500 MCM copper wires. Also note that they were not using any wire lube (until I told them to do so), they were pulling with a Bobcat tractor, and they snapped the pull line (possibly exceeding 10,000 lbs of tension). In my professional estimation, there is no chance of those wires having suffered zero damage to the insulation along that 30 foot length.

2. We know there was some damage caused by the pull through that LB, because it failed a megger test prior to the contractor's liquid tape and scrap plastic repair, and now it passes.

3. We know that the 400A breaker tripped 3 times a year ago. The amperage rating on a breaker is for continuous excessive-current draw over a period of time; it actually takes a much higher current flow to instantaneously trip a breaker, typically 5x the breaker?s rating. So the fault that tripped the breaker was likely over 2,000A. If the arc occurred in the areas where the contractor applied the Liquid Tape (at the inlet and outlet of the LB), we should be able to see significant physical evidence of damage caused by the arcing: burnt metal, melted insulation, black soot, etc. None of that was visible when I inspected the inside of that LB. I suspect that the damage that caused those faults lies further inside the metal conduit, between the LB and the inverter. The likely reason it stopped faulting (and the reason it passed the Megger test) is because, by the third time it arced, enough of the metal was vaporized to create an air gap too large for the voltage to jump. The megger tests are being performed with 1,000 VDC and the breakdown voltage of air is ~1,000V/mm. So as long as there exists an air gap of greater than 1mm at any point where the wire is damaged, the megger will not reveal that damage.​

So here is his response to our request to have that 30 feet of wire exposed and visually inspected:

How does he propose to replace a conduit body with a box without removal of conductors from at least one direction during that process:??

 

[big john]

I would get in touch with the cable manufacturer about testing recommendations.

Normally a high-pot is a commissioning-only test, but in this case where you have strong reason to believe that serious installation defects exist that might not be found with a 1kV megger, it may be warranted to use it to confirm cable integrity.

For example, this paper from Southwire suggests using it when damage is suspected, and says that a piece of XHHW 500MCM in good condition should withstand 8kVDC for 5 minutes.

I'd bet that cable would fail that test.

 

[kwired]

Somehow fill raceway with water and meg again??

 

[archingangel]

fire them

fire them

there are these things called tuggers that we electricians use so to next time you see some fool pulling wire with a tractor, a truck etc you should step in and say something and not stand there idly by.

 

[don_resqcapt19]

there are these things called tuggers that we electricians use so to next time you see some fool pulling wire with a tractor, a truck etc you should step in and say something and not stand there idly by.

If you are pulling through a possibly undersize LB in the wrong direction, it doesn't make what the source of the pulling force is.

 

[growler]

How does he propose to replace a conduit body with a box without removal of conductors from at least one direction during that process:??

I would kind of like to see how he does that one myself. Once you cut the conductors how much trouble would it be to slide off one section of conduit to check for damage. Once you find that it's damaged ( pretty certain ) then it's only logical to remove the conductors and replace.

 

[ActionDave]

How does he propose to replace a conduit body with a box without removal of conductors from at least one direction during that process:??

Good point.

 

[pjholguin]

IMO...filling the conduit with water is not the right method. The way to go
HiPot testing, if the cable is bad this will be the test to prove it.

Somehow fill raceway with water and meg again??

 

[kwired]

there are these things called tuggers that we electricians use so to next time you see some fool pulling wire with a tractor, a truck etc you should step in and say something and not stand there idly by.

Some of us smaller contractors can't afford every toy out there and have items that get higher priority then others, bur often are pretty creative at making something work - with potential consequences if they fail. I can imagine an improperly utilized tugger could be just as much of a problem as well.

If you are pulling through a possibly undersize LB in the wrong direction, it doesn't make what the source of the pulling force is.

Exactly, I have seen damaged conductors when hand pulling - probably not so much with conductors as large as the OP has but a mechanical puller would have not made any difference.

IMO...filling the conduit with water is not the right method. The way to go
HiPot testing, if the cable is bad this will be the test to prove it.

I agree, water is probably not the right method, may not be very practical in some instances either. I was kind of hypothetically pointing out that clean dry conductors may pass a meg test, but that doesn't necessarily mean there isn't insulation damage. Add some contaminants to the raceway interior (which time may eventually do) and you now have a place for that damaged insulation to leak enough to fail the meg test.

 

[Jon456]

How does he propose to replace a conduit body with a box without removal of conductors from at least one direction during that process:??

I have no idea how he proposes to replace the LB because, despite our demands for him to provide us with an advance written statement of the "methods & equipment" to be used for each warranty repair for our approval, he has only provided this information once (for replacement of our facility's damaged main feeders -- and even that one statement was vague to the point of worthlessness); all other repairs he's performed so far he's done without our knowledge, consent, or presence for inspection.

But if I wanted to replace that LB with a splice box without pulling the wires, I could do it.

 

[Jon456]

Somehow fill raceway with water and meg again??

This is what I wanted to do from the beginning. Over the objections of the contractor, we did fill all our buried PVC conduits with water and discovered a number of damaged wires. But this run is more difficult because the conduit is elevated EMT and it enters the side of one of our inverters. If we wanted to fill this conduit with water, we would have to move the inverter off the pad to avoid any possibility of water damage. Even then, we may not be able to fill the conduit completely to get a 100% accurate test (a problem we had even with our buried conduit).

 

[pjholguin]

Some of us smaller contractors can't afford every toy out there and have items that get higher priority then others, bur often are pretty creative at making something work - with potential consequences if they fail. I can imagine an improperly utilized tugger could be just as much of a problem as well.

I concur, I once saw a journeyman try to pull a set of 500MCM cables through a liquidtite 90? at the end of the run using a
tugger...crazy man, crazy man.

 

[pjholguin]

This is what I wanted to do from the beginning. Over the objections of the contractor, we did fill all our buried PVC conduits with water and discovered a number of damaged wires. But this run is more difficult because the conduit is elevated EMT and it enters the side of one of our inverters. If we wanted to fill this conduit with water, we would have to move the inverter off the pad to avoid any possibility of water damage. Even then, we may not be able to fill the conduit completely to get a 100% accurate test (a problem we had even with our buried conduit).

IMO, this is not the right test method for this conduit run. You should find an application that is an industry standard.

To quote the three stooges "That's why the water can't flow, there are wires in these pipes"

 

[kwired]

This is what I wanted to do from the beginning. Over the objections of the contractor, we did fill all our buried PVC conduits with water and discovered a number of damaged wires. But this run is more difficult because the conduit is elevated EMT and it enters the side of one of our inverters. If we wanted to fill this conduit with water, we would have to move the inverter off the pad to avoid any possibility of water damage. Even then, we may not be able to fill the conduit completely to get a 100% accurate test (a problem we had even with our buried conduit).

May get even more difficult to fill if set screw fittings were used:happyyes:

I usually have no problem with getting underground raceways full, they seem to get that way on their own. One instance I specifically recall - I buried PVC conduit on a Friday, came back next Monday to pull conductors. It was hot and humid - but of course the underground portion was cool and it condensed in there. No rain over the weekend either. Was not full but just over the weekend was enough condensation in there that my pull rope came out damp.