Running 110V next to 12V while at shore

[zinahewitt]

Hi All,

I have a Dufour 34 1975.
It never had shore power. I added a box with 30 amps, 3 switches with 2 used for outlets which I custom built somehow. {thanks youtube}

so I was planning to run an electrical wire , 110V , which will go into an outlet on the box, the wire will run in that brown piece
which runs along the boat, let us call it the Electric Conduit. This will go all the way to the V berth where I can put a generic socket.

That brown Electric Conduit thing runs from the back to the front of the boat and has the 12V wiring for lights and similar.

I was told and read one should not run 110V wire near 12V wire.
I still want to do this, so my questions are.

1. Should I do this ?
2. Do I need to use a conduit inside the brown one and if so which conduit type would you recommend ?


Thank you
Electricity and plumbing are not my strong suit.

 

[dlochner]

I was told and read one should not run 110V wire near 12V wire.

The concern is inducing an AC current in the DC wiring. This can only happen when there is AC flowing in the AC wire. So long as the wires are straight, not coiled the induced AC current is pretty small. This is "wireless charging" the way many small electrical devices are charged, things like cellphones, Apple Watches, and electric toothbrushes.

Whether the induced current on your boat is an issue or not, really depends on a lot of factors. On the DC side, if the circuit is used for sensitive electronics or LED lights, it might be an issue if the current is large enough. If the wire is solely used for incandescent lighting, probably not, but who uses incandescent lights on a boat anymore? Likewise, if the AC current is high, say running an electric heater or hair dryer, the induced current will be higher. But, if there is no DC device turned on, there will not be an issue.

Thus, while running AC next to DC might not be a problem, all the variables make the safer answer is to keep them separate.

 

[Davidasailor26]

ABYC doesn’t explicitly say that you can’t run the conductors together, only that if you do the AC conductors “shall be sheathed, bundled, or otherwise kept separate from DC conductors.” Generally if you’re using AC wire in a 3 conductor package it’ll be sheathed itself, which should meet the requirement.

Having said that, there are many other considerations that come with AC wiring which, if not done right, can affect not only your safety but also that of neighboring boats. If you don’t feel comfortable with the requirements and best practices it may be best to do further research or bring in a certified marine electrician.

 

[sailme88]

If you think about it, installing a Xantrex type battery conditioner requires that the AC & DC be in close proximity, Same holds true with an inverter. Just don't make a coil ( magnetic) zone that the other wires pass thru.

 

[jssailem]

I am unaware of any regulations that apply to this particular case.

I would be sure that the insulation on all the wires (both AC and DC) meets the requirement of the highest voltage present in the common conduit. Be sure there is adequate space throughout the entire run for all the wires. Cramming the wires together could create an opportunity for chafe issues.

 

[Davidasailor26]

Cramming the wires together could create an opportunity for chafe issues.

Bundling more wires together also has implications for their maximum ampacity, since they can’t dissipate heat as well as single conductors in air. ABYC lists this out in their wire gauge tables.

 

[DArcy]

Electricity and plumbing are not my strong suit.

Having ripped out miles of poor wiring from my boat, installed by people who's strong suits were not electricity, I urge you to become properly educated in marine AC wiring before attempting any electrical changes to your boat. Or just hire it out. As mentioned above, AC wiring can be unsafe if not done correctly. If you are not familiar with hot vs. neutral vs. ground or galvanic isolation, do yourself (and your boat neighbors) a favor and find a qualified marine electrician to help you.

 

[zinahewitt]

Having ripped out miles of poor wiring from my boat, installed by people who's strong suits were not electricity, I urge you to become properly educated in marine AC wiring before attempting any electrical changes to your boat. Or just hire it out. As mentioned above, AC wiring can be unsafe if not done correctly. If you are not familiar with hot vs. neutral vs. ground or galvanic isolation, do yourself (and your boat neighbors) a favor and find a qualified marine electrician to help you.

Hi D'Arcy,
Hope your day is going well.

One learns nothing from paying others to do things
plus from my experience most do a shoddy job and still bill you.

As mentioned by others, there is no "marine" code requirement except not "bundling" the wires and not crossing wires.
I have two quotes from KKMI and Andersen, one wants to put a conduit, one does not.
So even the "experts" can't make up their mind.

There is no option to cross wires here as this is going from a 110V circuit all the way to a 110V circuit.
So we are left with bundling.

So the question is would you be happy with
1. Not bundling and using no conduit. - I assume the proximity is enough of a problem at least it is in my industry which is telecom.

2. Using a conduit to the 110V just in case.

Being superstitious and a negative nancy who thinks everything will fail if you don't take care.
I plan to do number 2.
So I am trying to see what people recommend as far as the conduit material itself.

For home construction it is usually "metal".
However being Marine, I'd rather not add any metal.
That leaves me with plastic.

Cantex PVC would be the hardest option. - I can still bend it using the heat gun.
Liquid Tight non metalic would be second and give me some flex.
The last option would be some flex pipe like the bilge pipes - Bligeflex MultiFlex.

Do you have any suggestions ?

 

[Davidasailor26]

Split loom conduit is a very common choice for that purpose in boats. It gives good chafe protection and keeps things in order, while leaving the wires accessible when maintenance is needed.

 

[zinahewitt]

Split loom conduit is a very common choice for that purpose in boats. It gives good chafe protection and keeps things in order, while leaving the wires accessible when maintenance is needed.

Thanks.
This seems to be a better idea than mine

Fire-Retardant Split Loom, 1/2

Check out our Fire-Retardant Split Loom, 1/2

www.westmarine.com

As it is fire retardant.

 

[mermike]

Do you have any suggestions ?

Smurf tube:

Search Results for smurf tube at The Home Depot

Search Results for smurf tube at The Home Depot

www.homedepot.com

 

[dLj]

You need fire retardant in a boat - the link to the westmarine fire-retardant split loom would be preferred. Doesn't look like smurf tube is fire retardant ...

dj

 

[TDK]

How did your project go? We recently bought a 1975 Dufour 34 and are looking into adding shore power as well..

 

[jssailem]

@TDK Do it. It will enhance your boat and the experiences you have on it.

 

[LloydB]

Using MC cable to run your 120 circuit through that chase should cover all your your needs even if you decide to use an inverter to supply the AC while operating any DC circuits simultaneously when off the grid. ÖLFLEX® TRAY II / TRAY II CY could be one option but does not eliminate the need for chaff protection to other cables in the chase.