[Gremmel]

I am planning a boat dock project. We live on a bluff and have about 150' of steps to a small deck and are planning about another 50 to the boat dock.

I believe the boat dock would have a couple of 15amp /1hp lifts and few flood lights, a couple of 120 outlets and some low voltage lighting. I would also like to put some low voltage on the small deck. I am thinking 1 circuit for outlets, one for lights and 1 for the 2 motors.

OBTW, the hike to the deck represents about 6 or 7 stories of steps so a 3 way switch for some lights would be nice at the top.

So here are the questions I have so far:
I was planning on putting in a subpanel at the small deck which would later be moved/extended to the boat dock. Is 30amps enough? Can I do that on #6 or do I need bigger? What issues should I consider if I use aluminium (4-4-4?) for the run from main panel to the sub panel and run the circuits with 12/3 copper?

Is it enough to GFCI the circuit at the subpanel or do I need to put GFCI on each circuit as well?

I will contract an electrican to check my work and make the main connections but would like to go ahead and get the main run done ahead of time.

Thanks for any help,
Up a Creek

 

[J. V.]

Everyone says. "I will contract an electrician to check my work and make the main connections but would like to go ahead and get the main run done ahead of time".

This electrician would not work like that.

This does not sound like a DIY project to me. But if you are allowed to do this work as a homeowner and are going to have it inspected, I see no reason why we could not help you some.
1) How do you plan to get power down 150' bluff?
2) Why install a sub panel, just to move it onto the dock later?
3) Yes, every single receptacle on the deck and the dock need GFCI protection.
4) Is this a floating dock?

I would report back on how you plan to get power to the sub panel. Then we can take it from there.

 

[Stubbie]

There is no way to answer your question without knowing where your located ... what lake and what state ? There are extremely strict guide lines when wiring floating docks and inspections are mandatory. For example I'm familiar with Lake of the Ozarks, Missouri. There are many requirements as for earth grounding and system bonding, wiring methods, gfci, hardware, conduit etc...

Lake of the Ozarks also requires a licensed contractor with a license/permit to do electrical work on docks around the lake whether new or old, owners may not perform any electrical work. This is exteremely serious buisness and life safety is a priority in the wiring requirements and design.

The lake AHJ will likely have a guide lines brochere you can view to get an idea of what your contractor is required to adhere to as far as NEC and local electrical codes.

 

[al_smelter]

I'm chiming in with the others. I did the exact same project for my father at Smith Mountain Lake in Virginia. I can only reiterate that you are dealing with life and death around the water. You may very well be capable of doing this work. Just please be sure.

https://www.google.com/search?q=lak...chrome.0.57j0l2.4925&sourceid=chrome&ie=UTF-8

I spent last summer camped next to a family whose son was killed two years ago when electrocuted jumping off of a dock in West Virginia. It's a sad story.

 

[AllanJ]

For 30 amps at 240 volts you need #4 gauge copper or #2 gauge aluminum wiring for the main line down to the deck subpanel and for the lift circuit continuing to the dock. This will handle the two 15 amp 120 volt winches and leave capacity for other things.

For the 3 way switching for lights, power the lights from the subpanel and run a 14-3 line back to the house for the other switch. This will support about 300 watts of lighting.

The transformer or power supply for the low voltage lighting must be located close to where the lights will be installed. For LV at the deck and at the dock, use separate LV systems.

 

[Gremmel]

Thank you all for the replies.

J.V.: My intent was to run the main feed in conduit attached to the lower-outside of the steps to the deck. It may be possible to 'swing' the line to the deck area on poles but there are a lot of trees that may create issues in the future.

I was planning on putting the subpanel at the deck until we built the dock. The dock project may not happen until next summer. It will be a fixed dock; not floating. It seemed if I was gonna pull power to the deck I should pull the appropriate amount for the future dock.

Stubbie: Wheeler Reservoir; Alabama: TVA and Corp of Eng controlled.

Al_smelter: I appreciate that. One of the reasons I do a lot of homework before projects.

AllanJ: Thanks very much.

EDIT: I should add; I am good with having an electrician do all of the final electrical. I have done plenty of rough-in work and passed inspections. I would like to at least do the rough in for the 150' to the deck to save some money because I am currently "under employed" and have the time to do it.

 

[al_smelter]

I ran down the side of the step stringer in rigid conduit. There were two strategic places where the steps were 'broken' to allow for movement, and I installed expansion joints in those locations. It's been almost ten years now and still looks brand new.

 

[Toller]

I did this quickly (I assumed a total run 250', rather than doing it piece by piece...) but assuming you are running a 240v 30a circuit, #8 copper ought to be adequate. Check it carefully before you invest in heavy cable.

 

[al_smelter]

You might also consider about making the subpanel permanent on the deck and then running your dock circuits from there. 50 ft from panel to boathouse will have no appreciable voltage drop, and #12 wire from the sub could take 20 amp breakers if desired. The subpanel will require it's own ground rod.

As I said above, I ran steel to the bottom of the steps. We had no intermediate deck, but the steps emptied onto a flat about thirty feet to the ramp walkway. So I set a junction box at the bottom step and transitioned to PVC underground to the boathouse. I also left it in PVC across the ramp, well strapped to another junction box, where the circuits split to the hoist (single boat), lights (plenty, 3 way clear from the house, but that's another story), and receptacles.

EVERYTHING was well grounded and ground faulted.

 

[Gremmel]

I may leave the subpanel at the deck. TVA allows for a 4x8' closet on the dock that would seem to be a good place to place it for the long haul though.

BTW, when you mentioned the expansion joints, did you mean the PVC Slider type? Sounds like a good idea too because of the way wood expands/contracts.

Thanks all.
Up a Creek (Dan)

 

[Stubbie]

I may leave the subpanel at the deck. TVA allows for a 4x8' closet on the dock that would seem to be a good place to place it for the long haul though.

BTW, when you mentioned the expansion joints, did you mean the PVC Slider type? Sounds like a good idea too because of the way wood expands/contracts.

Thanks all.
Up a Creek (Dan)

Expansion joints are for the expansion of the pvc conduit for temperature fluctuations. They have only minimal benefit from movement of the structure the conduit is attached. The wire is terminated and only has what little slack is available for any change in expansion of the conduit due to structure or ground movement. In other words if the structure moves in a way that would increase the length of the conduit it will pull against the wire even it the expansion joint moves enough to compensate. There are installations with liquid tight that allow for the movement of the structure/dock.

Liquid tight conduit installed correctly is a better option in areas where movement is a problem or a possibilty.

I really think you would be smart to let an experienced contractor wire this dock of yours.

This is a drawing I detailed from Ameren Utility for my area of familiarity .. understand it is not inclusive of Lake Wheeler. It's just a helpful idea and is not your exact situation.

Frankly I would suspect an electrician is not going to like what you do unless it is exactly in compliance the wiring methods for Wheeler lake
.

 

[Stubbie]

　I dug out the checklist from my records ..... I'm just saying this is'nt typical DIY work ...

1. Consult AHJ for guidelines brochere​
   [*]Feeder from the main panel to sub panel shall be 4 wire for 240 volt system or 3 wire for 120 volt system and sized for the load.
   [*]Conduit that is buried from the building to the sub-panel shall be schedule 40 PVC for underground use.
   [*]Junction box on the outside of the building serving the dock shall be weatherproof.
   [*]The feeder from the sub-panel to the dock shall be schedule 40 PVC (sunlight resistant) and must be liquid tight flexible conduit at all pivot points.
   [*]The conduit from the J-box to the dock sub-panel or disconnect shall be sized for the conductors.
   [*]The sub-panel shall be at the seawall next to the dock ramp and shall have a disconnecting means.
   [*]All grounding conductors shall have continuous outer finish that is green including all bonding wires.
   [*]The grounding conductors shall be connected to the grounding bus in the sub-panel and to the ground rod. Grounding bus and grounded bus must be separated.
   [*]A grounding electrode shall be in place (at least eight (8) feet long and trade size of ½ inch).
   [*]The grounding conductor shall be sized correctly for the circuit (minimum #6) and attached with a separate clamp directly to the grounding electrode.
   [*]#6 grounding wire from the ground rod to the metal parts of the ramp with approved terminals attached with through bolts and lock nuts.
   [*]#6 grounding wire jumper shall be installed between all pivot points in the ramp, dock stiff arms, breakwaters, etc., attached with through bolts and lock nuts.
   [*]All metal enclosure and exposed metal parts of the electrical system shall be bonded to the grounding bus with approved terminals.
   [*]All metal parts, metal piping and all non-current carrying metal parts must be bonded to the panel board.
   [*]All outlet receptacles shall be GFCI protected unless the outlet is a dedicated outlet in an enclosed structure.
   [*]All general use outlet receptacles shall be a minimum 36 inches from the finished dock surface.
   [*]All outlets dedicated for a piece of equipment shall be of the Marine Twist Lock type and GFCI protected. A disconnecting means must be within 30 inches of outlet or approved pedestal installation.
   [*]All GFCI protected outlets receptacles shall work when tested.
   [*]All cabinets and cutout boxes shall be a minimum of ¼ inch of airspace between the enclosure and supporting surface.
   [*]All enclosures below eight (8) feet or exposed to weather shall be in weatherproof enclosures and suitable for wet locations with allowable weep holes.
   [*]All fixtures above eight (8) feet and below a roof or overhang shall be suitable for damp location.
   [*]All general use receptacles shall have an attachment plug cover ("in use" type).
   [*]All switches shall be in weatherproof enclosures or cabinets.
   [*]Receptacles, switch boxes and junction boxes shall not be within six (6) feet of a ladder for the dock.
   [*]Any metal ladder on the dock shall have #6 wire jumpers to dock frame from ladder base and to ladder if hinged (frame can be bolted to dock frame).
   [*]A detachable ladder needs to have specs showing that it is bondable
   

​

　
Notes:

1. 
   [*]2005 National Electrical Code (NEC) applies with Authority having jurisdiction (AHJ) additions.
   [*]Non-metallic sheathed cable may not be used (Romex).
   [*]All wiring methods and conductors shall be suitable for wet locations (check exceptions).
   [*]All wiring shall meet 2005 NEC Article 553, "Floating Buildings" for private dwelling docks.
   [*]All wiring shall meet 2005 NEC Article 555, "Marinas and Boatyards" for all other docks.
   [*]Contact your local fire department for an inspection within seven days of supplying power to the dock.
   

 

[mpoulton]

There were changes to the NEC recently regarding dock power. Something about GFPE for shore power systems. I don't know the details, and I don't know if it applies to power on docks that do not provide shore power for boats. Does anyone know if those changes will be applicable here?

 

[al_smelter]

　I dug out the checklist from my records ..... I'm just saying this is'nt typical DIY work ...

1. Consult AHJ for guidelines brochere​
   [*]Feeder from the main panel to sub panel shall be 4 wire for 240 volt system or 3 wire for 120 volt system and sized for the load.
   [*]Conduit that is buried from the building to the sub-panel shall be schedule 40 PVC for underground use.
   [*]Junction box on the outside of the building serving the dock shall be weatherproof.
   [*]The feeder from the sub-panel to the dock shall be schedule 40 PVC (sunlight resistant) and must be liquid tight flexible conduit at all pivot points.
   [*]The conduit from the J-box to the dock sub-panel or disconnect shall be sized for the conductors.
   [*]The sub-panel shall be at the seawall next to the dock ramp and shall have a disconnecting means.
   [*]All grounding conductors shall have continuous outer finish that is green including all bonding wires.
   [*]The grounding conductors shall be connected to the grounding bus in the sub-panel and to the ground rod. Grounding bus and grounded bus must be separated.
   [*]A grounding electrode shall be in place (at least eight (8) feet long and trade size of ½ inch).
   [*]The grounding conductor shall be sized correctly for the circuit (minimum #6) and attached with a separate clamp directly to the grounding electrode.
   [*]#6 grounding wire from the ground rod to the metal parts of the ramp with approved terminals attached with through bolts and lock nuts.
   [*]#6 grounding wire jumper shall be installed between all pivot points in the ramp, dock stiff arms, breakwaters, etc., attached with through bolts and lock nuts.
   [*]All metal enclosure and exposed metal parts of the electrical system shall be bonded to the grounding bus with approved terminals.
   [*]All metal parts, metal piping and all non-current carrying metal parts must be bonded to the panel board.
   [*]All outlet receptacles shall be GFCI protected unless the outlet is a dedicated outlet in an enclosed structure.
   [*]All general use outlet receptacles shall be a minimum 36 inches from the finished dock surface.
   [*]All outlets dedicated for a piece of equipment shall be of the Marine Twist Lock type and GFCI protected. A disconnecting means must be within 30 inches of outlet or approved pedestal installation.
   [*]All GFCI protected outlets receptacles shall work when tested.
   [*]All cabinets and cutout boxes shall be a minimum of ¼ inch of airspace between the enclosure and supporting surface.
   [*]All enclosures below eight (8) feet or exposed to weather shall be in weatherproof enclosures and suitable for wet locations with allowable weep holes.
   [*]All fixtures above eight (8) feet and below a roof or overhang shall be suitable for damp location.
   [*]All general use receptacles shall have an attachment plug cover ("in use" type).
   [*]All switches shall be in weatherproof enclosures or cabinets.
   [*]Receptacles, switch boxes and junction boxes shall not be within six (6) feet of a ladder for the dock.
   [*]Any metal ladder on the dock shall have #6 wire jumpers to dock frame from ladder base and to ladder if hinged (frame can be bolted to dock frame).
   [*]A detachable ladder needs to have specs showing that it is bondable
   

​

　
Notes:

1. 
   [*]2005 National Electrical Code (NEC) applies with Authority having jurisdiction (AHJ) additions.
   [*]Non-metallic sheathed cable may not be used (Romex).
   [*]All wiring methods and conductors shall be suitable for wet locations (check exceptions).
   [*]All wiring shall meet 2005 NEC Article 553, "Floating Buildings" for private dwelling docks.
   [*]All wiring shall meet 2005 NEC Article 555, "Marinas and Boatyards" for all other docks.
   [*]Contact your local fire department for an inspection within seven days of supplying power to the dock.
   

I agree this is not *TYPICAL* DIY work. However, we do not know your capabilities, and you don't seem to be asking ignorant questions like "what's the green screw for?". And if you are going to attempt it with or without help regardless, someone knowledgeable may as well reply to these threads.

The above quote is a great list to start with. Many items on it are a given [like green colored ground wire], but there is a wealth of information in there that you will need to take in. Also as stubbie says, you MUST get a copy of the latest requirements for your area, and then follow them to the letter.

There is no question [to me] that you should, at the very least, have a qualified electrician on retainer or accessible for every step of this project. Helll, I still ask for help once in a while and I've been an electrician for over thirty years. Things change, like codes, materials and techniques.

Be safe and have fun with it.

 

[Gremmel]

Thanks for the awesome replies. It is really great information.

I do have an electrician. I will have him do the work. I will have him come and quote the deck job and we will talk about me doing the rough-in for the main feeder and PVC work. The run down the steps/bluff will be labor intensive and require ropes and some rapelling (I have experience here although I am getting a little long in the tooth). If I do the work it will be per his instruction. He will do everything else.

I was hoping to get a definitive answer on the size of wire but I will get it from him when we talk.

Thanks again everyone for the information. :thumbsup:

 

[Stubbie]

Size of wire

Hard to say from what you listed but typically a 6/12 100 amp sub-panel is used for docks either on a pedestal shore side (type 3R) or on the dock in a rainproof closet. Now the 100 amps is way more than you need but if allows enough circuit breaker spaces to provide for boat lifts, receptacles , and lighting. Your can power it with less than 100 amps say 50 or 40 amps. All wire must be insulated and color coded and rated wet location. No aluminum wire.

Determine your load at the dock under the heaviest possible load screnario. Use an online voltage drop calculator like here ... Use 240 volts as your supply voltage to control your wire size.. 120 volts for the feeder IMO will create too much voltage drop depending your loads especially lift motors. If you plug both into the voltage calculator you will be able to compare the differences. 240 volts will also give you some nice options for dock specific lifts with 240 volt motors and other equipment. Remember everthing must be gfci protected.


http://www.electrician2.com/calculators/vd_calculator.html

 

[J. V.]

Remember that the wire is heavy and will want to drop down this embankment. You might require wedges designed just for this purpose. I would hate to see you pull all that wire in, just to find it in a pile at the bottom the next day. Ask your electrician.

 

[herdfan]

I spent last summer camped next to a family whose son was killed two years ago when electrocuted jumping off of a dock in West Virginia. It's a sad story.

It is sad, but if it is the story I am thinking about, it is not related to a dock. A houseboat was leaking current into a lake and when the boy grabbed the ladder to climb back up on the boat, he was electrocuted.

 

[dmxtothemax]

Are the two lift motors used at the same time ?
If so thats 30a already,
leaves very little for the other outlet and lights !
Consider using bigger cable I would go for
something like 60a cable.
Is there going to be 240 or just 120 ?