I may be running a branch circuit to a stationary dock soon. The dept of environmental management put in a stipulation saying that in the last 100 feet to the dock, there can be NO disturbance, ie: the utilities (water & electric) must see daylight. In other words these utilities must be on the surface, no digging of any kind. We cannot put up a rail to run our conduit along in this area. I need to find a CODE COMPLIANT wiring method where I can run the branch circuit on the ground. What bothers me is they can have stone steps in this area, dug into the side of the slope, but I cannot dig even 12 inches for a wire or conduit. I have considered electric vehicle cable (rated for extra hard use, wet locations), it would need to be sunlight resistant also. I have also considered sch 80 pvc either as a conduit for thwn or as a protective sleeve. The wiring method has to be at the side of a 6 foot wide foot path. How would I secure these to be code compliant? Any ideas for another method? The conditions are as follows: salt water, tidal, though it may only see an occasional extreme high tide, salty atmosphere (fog, dew, etc). Thanks for any assistance
RickG: Vehicle cable (rubber cord) won't fly, as cord cannot be used for permanent wiring methods. What are you doing with the water line?, or is that just going to lay on the ground?
Have you spoken to the local AHJ for his input? He may be your best bet, as he has should be familiar with the local area and situations. Conduit (PVC80 or RGC w/PVC Coating) would be the way, but you need something to strap it to, and soil don't count.
One of the specialty companies make a "dunnage block" in plastic, that we use around here on roofs, to support and secure conduits, perhaps you could adapt that for the PVC or RGC. John
#85188 - 06/04/0307:12 AMRe: Wiring method to a dock
HotLine1: The water line will lay on the ground as far as I know, (that probably violates some plumbing code). Unfortunately, I am the AHJ, and do not have all the answers. As an AHJ I have not encountered a situation like this where they cannot bury the wiring method , or have a structure to secure to. I have considered laying pressure treated wood on ground, then securing the PVC to that... but, in an extreme high tide it may float and the wave action may damage the conduit system. Not to mention the chemicals that will leech from the pressure treat into the water. Type W cable is OK (say the engineers), & I have approved it in the past as a wiring method along the movable gangways to the floating docks, as it must be flexible, & it can be immersed in salt water. I wonder if I can go with a combination of type W and PVC conduit somehow. All this for a plug and a few lights. Sometimes, being the AHJ in not such a good thing! RickG
#85189 - 06/04/0307:13 AMRe: Wiring method to a dock
Suggest you have the enviromentalists supply you with a reference for thier spec. If they cannot or do not have any believable reason for it, tell them that the NEC will be the rule followed. Suggest you look into boring the conduit from the power source to the dock, or as close as you can get. Good luck
#85194 - 06/05/0310:49 PMRe: Wiring method to a dock
Rick: You mention treated wood (4x4 I guess). Arlington Mfg makes a composite item (like a 4x4) that accepts strut straps to secure conduit. Maybe you could work out a deal with the plumbing contractor, and mount the water and elec. conduits like that. Or, how about a concrete/masonry block??
You also could get away from the "float" problem with the masonry block, and RGC conduit. (PVC coated for the salt air). I know you are talking $$$ in material and labor, but you are in a tight position.