No Shore Power on Board

May 17, 2004
5,028
Beneteau Oceanis 37 Havre de Grace
Admittedly splitting atoms here.. but voltage between wires creates an electric field and current in the wires create a magnetic field. Both of which cause a mechanical force between conductor wires that modulates at 60 hz for wires carrying AC.
Makes sense, and probably consistent with uncledom's wire jumping with current inflow. Still, houses are filled with solid core wire and it's not like you hear every day about the wires failing from work hardening due to oscillating EM fields.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Do you have any citations for this, like scientific papers, industry best practices, trade journal articles, etc.? I confess that while I'm a degreed electrical engineer, and have worked as one for over 30 years, I have never heard or read of anyone expressing any concern over work-hardening of solid copper wire due to vibration from 60Hz.

I'd like to also ask, if this is a problem for solid conductors, why isn't it also a problem for stranded? Wouldn't they vibrate and harden, too, and subsequently break?
 

walt

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Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
I would think the forces from primarily the magnetic field would be the same for either stranded or solid wire. The vibration from current is just something sort of interesting and not really important for the boat application. Its likely just the mechanical vibration that happens in a boat that drives the stranded wire requirement. Im just guessing.. (retired analog EE)

This came up in another topic but its the one place where the magnetic field created by the current did do something "bad" and likely (guess on my part) applies for both sold or stranded wire. I just copied a snip from that thread:

I waded through the IEEE article on AFCI and thought that this was very interesting - here is the link again http://combinationafci.com/resources/doc_ieee_combination_afci.pdf

There is a section in there on how shorts in the AC wiring should have blown a fuse but didnt

"The conditions when the two conductors of a cord come in contact, as the result of cord overheating or insulation damage, are significantly different. In this case the wires, once they make contact, can move apart by normal magnetic forces. The typical fault current and voltage for such an event, shown in Fig. 3 " Results were that the current pulsing creates a lot of heat but not enough RMS current to blow the fuse or that it takes too long to blow the fuse.
 

Ross S

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Oct 20, 2011
120
Precision 21 Great Sacandaga Lake
Do you have any citations for this, like scientific papers, industry best practices, trade journal articles, etc.? I confess that while I'm a degreed electrical engineer, and have worked as one for over 30 years, I have never heard or read of anyone expressing any concern over work-hardening of solid copper wire due to vibration from 60Hz.

I'd like to also ask, if this is a problem for solid conductors, why isn't it also a problem for stranded? Wouldn't they vibrate and harden, too, and subsequently break?
There is no concern for 60Hz in your house or boat or any other application that the average person would generally see. Otherwise solid wire would also not be recommended for installation in your house.

Solid wire will work harden with vibration. Stranded wires will too, but you'll find that it takes MANY more cycles to do so. As it relates to boats the possible mechanisms for wire damaging vibration are engine induced vibrations or general vibrations as the boat move through the water (thinking pounding through waves). And generally if the wire is installed reasonably it won't happen in days, weeks or months. It'd be years or more likely decades.

Are solid strand wires on boats inherently unsafe? No. Boats wired with solid strand are not bursting into flames and plunging into the depths the world over. However, boats wired with solid strand are more prone to a wiring failure than boats with stranded wire. And a wiring failure in the wrong place and at the wrong time could be a hazard. Hence the stranded wire is now the recommended best practice.
 
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Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
Back to the point, stranded wire is also required by US Coast Guard standard. It can be THNN machine wire rather than finely stranded, but it must be stranded. It's not just a recommendation. Yes, I've seen solid wire crack.
 
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jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
However, boats wired with solid strand are more prone to a wiring failure than boats with stranded wire.
Can you please elaborate on this, or provide a citation?
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Neither the USCG nor ABYC require tinned wire, as far as I am aware. Stranded, yes. Tinned, no.
(BTW, we should be careful here to set the context as that for recreational vessels, as the standards for commercial and/or passenger vessels are different.)
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
So, I learned something today. I had never paid much attention to "code" for boat wire, and today learned about the stranded requirement for 120VAC. Good to know. I wonder what I have? I know the 1984 Catalina 36 has Romex (solid conductor).

One thing I know I have is solid, #8, uninsulated copper for my lightning bonding system.
 
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Ross S

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Oct 20, 2011
120
Precision 21 Great Sacandaga Lake
Neither the USCG nor ABYC require tinned wire, as far as I am aware. Stranded, yes. Tinned, no.
(BTW, we should be careful here to set the context as that for recreational vessels, as the standards for commercial and/or passenger vessels are different.)
I believe that tinned wire is required per ABYC E-11. The tinned requirement is also mentioned in my earlier "citation".
 
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jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
I believe that tinned wire is required per ABYC E-11. The tinned requirement is also mentioned in my earlier "citation".
I can't find a requirement for tinned wire in ABYC E-11. All I find is two instances of:
"Conductors and flexible cords shall be stranded copper according to TABLE XI."

However, I did find this:
"Some people think that only tinned wire is allowed. This is not true. Marine wire does not have to be tinned. Neither the US Coast Guard regulations or the ABYC standards require tinned wire. But tinned wire is less subject to corrosion and lasts longer. Many marine professionals insist on using only tinned wire. It is more expensive than un-tinned wire. But boat wire must be marine wire whether it is tinned or not."
http://newboatbuilders.com/pages/elect.html
 

Ross S

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Oct 20, 2011
120
Precision 21 Great Sacandaga Lake
I can't find a requirement for tinned wire in ABYC E-11. All I find is two instances of:
"Conductors and flexible cords shall be stranded copper according to TABLE XI."

However, I did find this:
"Some people think that only tinned wire is allowed. This is not true. Marine wire does not have to be tinned. Neither the US Coast Guard regulations or the ABYC standards require tinned wire. But tinned wire is less subject to corrosion and lasts longer. Many marine professionals insist on using only tinned wire. It is more expensive than un-tinned wire. But boat wire must be marine wire whether it is tinned or not."
http://newboatbuilders.com/pages/elect.html
I stand corrected. It seems that tinned wire is only a recommendation.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
That's fine. I used to think it was so important, but then I found that the tin had gone black on Ancor marine wire I had installed, where moisture had wicked up the insulation. I think keeping wire dry is more important than plating.
 
Nov 30, 2015
1,336
Hunter 1978 H30 Cherubini, Treman Marina, Ithaca, NY
Are we done with the wiring preferences? Good!

I’d like to cap off this thread with a few final comments, based on findings. The original main breaker was bad, and the replacement also seemed to fail...initially after installation. None of the 110V outlets proved functional, as tested with a small portable AC fan that I had on board. I was dumbfounded, or maybe just found dumb. I also found a tripped GFCI receptacle in the head. Reading a previous thread here on SBO I thought...well that’s gotta be the issue, assuming the outlet was connected in series. Nope, still no power to the outlets. I should also mention that I had no other devices plugged into other outlets around the boat, as I feared a potential short occurring somewhere I hadn’t looked.

Yesterday, we got together for a refreshing respite from the boat maintenance with a new friend and his lovely wife, on our boat. While chatting, we discovered that @Mohawk Jack is a gifted electrical contractor working on naval destroyers. He casually asked how my shore power issue was going, having read it here, so I simply :(:( expressed my inability to resolve, and indicated I was going to hire a professional electrician to review.

So Jack asks “Do you have a multimeter?”...and then the lesson began.

After confirming each of my previous evaluations and performing additional monitoring, he agreed that we had power to the breaker cabinet. Throwing the main breaker we had voltage on both poles. I was then asked to test the outlets with my portable fan once again, the result...still no power. :banghead::soapbox:

Therefore my new genius friend, asks if I could try another appliance, so I plug the microwave into a different receptacle and a resounding beep occurs with the clock flashing. :eek::kick::dancing:

Jack looks up from the breaker cabinet with a piercingly smug grin :) and says...”I think your fan is bad too.”

I sincerely want to publicly thank @Mohawk Jack for his generous efforts and owe him a debt of gratitude. I also want to say that this recovery was only possible through contacts made on this SBO forum. So far, the costs associated with electrical repair were $35 for the replacement breaker and a couple of Gatorades. I can do better than that...

It also appears that my Cindy and his Jeanne hit it off quite well while the dudes operated.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
That's funny. I'm such a nerd that I always use my receptacle tester (with GFCI test button) when I check AC. I'll have to remember to check that, too!
 
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Feb 6, 1998
11,665
Canadian Sailcraft 36T Casco Bay, ME
I believe that tinned wire is required per ABYC E-11. The tinned requirement is also mentioned in my earlier "citation".
There is no ABYC requirement for tinned wire. Stranded wire that meets UL1426 is what is recommended.
 
Jan 19, 2018
31
Hunter Cherubini 30 Cayuga Lake, NY
That was not a Smug Grin, that’s my normal Shit Eatin’ Grin, according to my wife. I was glad to help and the cold drink was much appreciated. When I show up on a ship I usually start with, “ Hello, I’m from the government and I’m here to help.” That usually get a good laugh.
-Jack
 
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