View Full Version : Best way to run electrical to residential boat pier?
PB 21
May 28, 2009, 10:07 AM
I am wondering if anyone has any experience with wiring up a residential boat pier? Im not sure if its best to install a weatherproof sub panel at the end of the pier and then come out of it with all of the associated loads such as 240 v twistlock, 120 v gfci outlet, lighting, boat lift power and jet ski lift power.
OR
I have noticed some of the neighbors have different types of white, pagoda / marine power pedestals that appear to have a photoelectric controlled light at the top and outlets on the sides controlled by internall breakers. If I use on of these can I use it as a subpanel and feed the boat lift and jet ski lift and maybe any future expansion demands?
P.S. A 1 1/4 pvc conduit has already been ran to the pier from a jbox on the outside of the house with a two pole 50 and #8/3 to the jbox from the panel.
Any help would be greatly appreciated
stanfortyman
May 28, 2009, 11:30 AM
I very strongly feel this is NOT diy work. At least not unless you are very well versed in electrical work and the NEC.
If you already ran some type of cable out to the dock area you are already off the a bad start. You MUST have an insulated ground to a dock/pier service. The ground you have in that cable is most likely not insulated.
PB 21
May 28, 2009, 11:44 AM
Stanfortyman Let me first start by saying Thanks for replying. When the house was built the homeowner had a 8/3 ran to a jbox on the side of the house and a conduit run underground to the pier from the box. The conduit is currently empty and I plan on calculating voltage drop in the circuit (I think #4 THHN will be fine its about 200 feet to the end of the pier from the jbox) and pulling the conductors through the conduit and splicing them to the 8/3 in the jbox at the house. What I'm not sure of is how to distribute power in the cleanest and most efficient manor at the end of the pier. I feel like a marine pedestal is a lot cleaner than a sub panel out there just was wondering if anyone has used one of these to serve all the electrical needs the customer will have on the pier.
KISS
May 28, 2009, 12:12 PM
You can start by placing a NEMA 4X enclosure at a convenient spot and place a sub-panel in it. You may want a weatherproof disconnect near the dock. I don't know if it's required. Seems like it should be.
A small pad (optional) and a few 4 x 4's and some galvanized Unistrut and your set if you want to make a way to mount it.
If the dock is ever hit by anything like storms etc, then replacing from that subpanel is all you need to do.
A company that has a lot of pedestals is Midwest Electric Products, Inc. (http://www.midwestelectric.com), so you can check out their site.
Instructions for reading the NEC code online is in the sticky in this section.
In hindsight, a separate conduit for low voltage might have been useful too.
You probably want to feed the subpanel with a GFCI breaker as well.
You need #4 with a #6 grounding conductor for a 2.6% drop at 240 V at 50 A non-continuous.
You need #1 with a #4 grounding conductor for a 2.6% drop at 120 V at 50 A.
Actual loads and distribution in the panel can better be used to accurately size the conductors based on the neutral current expected. The neutral current is the difference flowing in each leg.
PB 21
Jun 4, 2009, 04:32 PM
Just wanted to add that I did in fact find a pedestal that worked great for my application. I was able to order it with extra breakers and used it as a power port location as well as a sub panel for other loads. In case anybody else is reading this and looking for the same thing I would highly recommend Rob with Dock builders supply at DockBuilders.com