ECN Forum Forums Code Related Discussion NEC & other Code issues Walkway and boat dock

I called my idea 'silly' as a way to downplay it. Call it modesty. There's no harm in doing so, but there is no code requirement - yet! Were this a pool, then there would be a requirement for an 'equipotential grid.'

I'm not aware of any conduit that requires support every three feet. Though, as my earlier description of using strut made clear, I encourage supporting conduit in excess of 'code minimums' where I believe the conduit will be subject to additional loading ... as when a kid climbs on it!

"Stray voltage" and "transient voltage" are terms sometimes used to describe folks getting shocks while swimming. These instances have almost always involved three things:
1) CLEAN fresh water;
2) A pool shell that was effectively insulated from the ground around the pool; and,
3) A municipality-owned electrical utility that was using the earth as a return path for it's various transformers.

The NEC adopted a few things in an attempt to address these issues. The first was to make an equipotential plane around the pool. The next was to require you to "bond" the water, by bonding a piece of metal that was in contact with the pool water.

This installation seems to be a typical Article 555 pier. There are at least 50 of them within a mile of my house and most have power. I can get pictures of the "good, bad and ugly" if you guys want to see some.
You can't confuse this with the Article 682 "natural and artificially made bodies of water" because that refers to equipment in the water, not above it on a pier.
I agree there are inconsistent rules between the two but "welcome to the NEC"

Reno:

Check 352.30

"I'm not aware of any conduit that requires support every three feet."

I understand you do not adhere to the 'minimums' within NEC, but just an FYI.

With that long a straight run, you also need to be thinking about expansion joints.

OK, expansion joints now enter the debate. I thought of bring it in a few posts back, but decided to wait.

NC lake area, venture about 85-105 degree swing??

Add in the proper straps that allow movement of the PVC, as opposed to the 2-hole that fit and screwed really tight.

352.30? By golly, it does say every 3-ft. for the smaller PVC. Thank you!

I don't think I've ever seen it done, though ... hence my comments about it drooping, etc.

I would say, it would be more like 105 down to the teens. I would design for 100 degrees. Even here in the sub tropics we need to deal with 85 degrees or so (in the shade)and it never freezes here. Direct sunlight will add at least 20 more degrees, particularly over a solid surface like a roof, concrete slab, masonry wall etc.
PVC may be the worst for expansion rate and it will pull apart if it is too tight. That "droop" may be a good thing if it is hot. I went with EMT in my screen cage just for that reason but it is not really an option on a boat dock here because it will rust out right away. YMMV on a freshwater lake but it is still just a matter of time.

Reno:
Don't feel too bad, not a lot of guys ever saw that Article.

Heck, I still 'preach' expansion joints to a few!

We talked about this in this thread and I said I would give you the good, the bad and the ugly.

This is a good one
Note the pipe to the outboard motor goes underwater.



This is the bad
Those Carlon 2 holers just disintegrated.



The ugly. Note the galvanized octagon box is totally gone and the keyless is hanging by the wires

One of the 'things' my work Twp does not have is waterfront except the Twp ramp into the river, and a "Marina" I have not been to in 15 years.

Home, is another story. What "New" I have seen is PVC, PVC boxes, SS boxes. Yes, there are ugly ones also, I'll see if I can get some pics in the next week or so.