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Discussion Starter · #1 ·
Has anyone had to make splices exposed to intermittent submersion in saltwater? We have 1/0 feeders with taps (up to 5 wires on a single splice) to individual pedestals on a dock that need a better method of waterproofing. Usually, we would use polaris connectors with a combination of scotchkote, scotchseal and super 33 tape. In the past on sumps, or other fresh water systems, this has worked well. However, that combo is not holding up to the saltwater. We are now looking at scotch cast but there are many different types and i don't see any that are rated for salt water application specifically. I called 3M to see what they recommend and they told me they cant recommend any of their products for what I am doing. Surely I am not the only one who has had to do this. Any ideas?
 

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Only done single wire splices on a dock....and that was with multiple heat shrink cover layers extending along the cable. I have seen some multiple splices overseas ; done with using a pvc box c/w fittings to seal and using a small aquarium type compressor to pressurize the box to keep out the seawater . Many Telcos use a compressor system on their underground cables for the same reason.
 

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splices submerged in seawater (intermittent or not) is just bad planning, and ultimately a fail.

jmo, your results may vary (but it doesn't sound like they are)
 

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Old Grumpy Bastard
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splices submerged in seawater (intermittent or not) is just bad planning, and ultimately a fail.

jmo, your results may vary (but it doesn't sound like they are)
Docks built on tidal waters are all subject to flooding and if you aren't going overhead they will at some point be underwater, there is no fighting that aspect of tidal conditions.
 

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Arsholeprentice
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Docks built on tidal waters are all subject to flooding and if you aren't going overhead they will at some point be underwater, there is no fighting that aspect of tidal conditions.
Plus you have waves and storms, that stuff is gonna get wet.

What about PVC boxes with strain reliefs, then make the splices in the box. It may not protect it 100% but it would be better than without the box, maybe prolong the lifespan anyway.

How exactly is this being fed? Conduit to the pedestals?
 
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Old Grumpy Bastard
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Plus you have waves and storms, that stuff is gonna get wet.

What about PVC boxes with strain reliefs, then make the splices in the box. It may not protect it 100% but it would be better than without the box, maybe prolong the lifespan anyway.
This is why I asked how much they want to spend.

If you bring your cables into a fiberglass box through strain relief connectors, make your splices inside and fill the box completely with silicone, install the cover and then coat the entire box with a sealing resin mastic you will have an assembly that will last a long while but this is not an inexpensive way to go.
 

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I am having trouble figuring out if the wiring is in conduit up and into the pedestals, if it is in boxes below the deck surface, or if it is open conductors spliced in the open air?
 

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Docks built on tidal waters are all subject to flooding and if you aren't going overhead they will at some point be underwater, there is no fighting that aspect of tidal conditions.

flooding doesn't seem to be what the OP was describing. I would not characterize that as "intermittent submersion". maybe I'm reading the post wrong.
 

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Discussion Starter · #11 ·
3M has a slew of TOTAL encapsulation epoxies// resins that you need to explore.

IMHO, they're what you want.

BTW, I'll bet that you talked to someone 'educated' by 3M's attorneys.

So, they ducked the question.
That was the impression I got from them. I'm getting some scotchcast quoted right now for it.
 

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Discussion Starter · #12 ·
splices submerged in seawater (intermittent or not) is just bad planning, and ultimately a fail.

jmo, your results may vary (but it doesn't sound like they are)
I would have designed it differently. The harbor master got the docks with conduit and boxes built into them to match the existing docks. There are so many points of potential failure with the docks. The docks just have 1 1/2" pvc butted up to each other where the docks come together and the n19 Christy boxes built into the dock have a hole in the bottom to let sea water flow in and out. Many of their other docks are done in rigid and have far less issues.
 

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Discussion Starter · #13 ·
I am having trouble figuring out if the wiring is in conduit up and into the pedestals, if it is in boxes below the deck surface, or if it is open conductors spliced in the open air?
We have 2x runs of 1/0 3phase feeders. They run through the center of the dock and hit 7 concrete boxes built into the docks spaced about every 30 ft. From each box 1-3 pedestals are tapped off the feeders. So there are alot of connections. To make things interesting, the bottom of each box has a 2" hole for water to drain out of. Only problem is that the water line in the box is about 3in deep inside the box. (Deeper when 50 sea lions pile up on top of each other on a single section.) That's what I mean by intermittent submersion. We are going to jam some pvc above the water line for our connections to lay on and go with scotch cast 85-14 for the feeders. Copper split bolts inside.
 

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We have 2x runs of 1/0 3phase feeders. They run through the center of the dock and hit 7 concrete boxes built into the docks spaced about every 30 ft. From each box 1-3 pedestals are tapped off the feeders. So there are alot of connections. To make things interesting, the bottom of each box has a 2" hole for water to drain out of. Only problem is that the water line in the box is about 3in deep inside the box. (Deeper when 50 sea lions pile up on top of each other on a single section.) That's what I mean by intermittent submersion. We are going to jam some pvc above the water line for our connections to lay on and go with scotch cast 85-14 for the feeders. Copper split bolts inside.
Is that at the Wharf or the Harbor?

I used to do a bunch of work on the wharf about 12-13 years ago... It was always interesting stuff.
 

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Discussion Starter · #15 ·
We have 2x runs of 1/0 3phase feeders. They run through the center of the dock and hit 7 concrete boxes built into the docks spaced about every 30 ft. From each box 1-3 pedestals are tapped off the feeders. So there are alot of connections. To make things interesting, the bottom of each box has a 2" hole for water to drain out of. Only

Its problem is that the water line in the box is about 3in deep inside the box. (Deeper when 50 sea lions pile up on top of each other on a single section.) That's what I mean by intermittent submersion. We are going to jam some pvc above the water line for our connections to lay on and go with scotch cast 85-14 for the feeders. Copper split bolts inside.
Is that at the Wharf or the Harbor?

I used to do a bunch of work on the wharf about 12-13 years ago... It was always interesting stuff.
Actually, it's down at the Moss Landing harbor. Any electrical near the ocean tends to get weird quick. It's a great place to work during the summer though.
 

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It sure is fun... I remember doing a lot of work at the SC wharf during the summer....

I miss those days!
 

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That sounds like a bad design. I have done a couple of floating docks before, and there was never any splices in those small manholes/Jboxes. The feeders were "G" cable. They got pulled through those man holes, and went in and out of the dock boxes. The "G" cable is meant for the constant submersion, and came out the side of the dock, and up to the dock box. When it was all done, only a little bit of "G" cable was exposed underneath, and was covered by the dock box.

I remember very well getting the heavy feeders through the boxes with a Gallagher sized Mellon smasher!
 

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The splice sounds like it's in a very grey area.
555.9 Electrical Connections.
Electrical connections shall be located at least 305 mm (12 in.) above the deck of a floating pier. Conductor splices, within approved junction boxes, utilizing sealed wire connector systems listed and identified for submersion shall be permitted where located above the waterline but below the electrical datum plane for floating piers.
All electrical connections shall be located at least 305 mm (12 in.) above the deck of a fixed pier but not below the electrical datum plane.
555.2 Definitions.
Electrical Datum Plane.
The electrical datum plane is defined as follows:
(1)In land areas subject to tidal fluctuation, the electrical datum plane is a horizontal plane 606 mm (2 ft) above the highest tide level for the area occurring under normal circumstances, that is, highest high tide.
(2)In land areas not subject to tidal fluctuation, the electrical datum plane is a horizontal plane 606 mm (2 ft) above the highest water level for the area occurring under normal circumstances.
(3)The electrical datum plane for floating piers and landing stages that are (a) installed to permit rise and fall response to water level, without lateral movement, and (b) that are so equipped that they can rise to the datum plane established for (1) or (2), is a horizontal plane 762 mm (30 in.) above the water level at the floating pier or landing stage and a minimum of 305 mm (12 in.) above the level of the deck
 
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