Reverse Polarity

[K_V_B]

Originally Posted by letsgetsailing3

The only reason we're having a debate on standards is because KVB said something that was incorrect, and then tried to reconfigure the conversation to try and make what he said correct.

I'll have to disagree here. I was not found incorrect. Merely in disagreement...


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[letsgetsailing3]

Originally Posted by K_V_B

I'll have to disagree here. I was not found incorrect. Merely in disagreement...


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You claimed polarity didn't matter, which is incorrect.

[svlamorocha]

Originally Posted by exMaggieDrum

One thing I have been intending to add: appliances not designed for marine use often have the neutral and ground bonded within the unit. This can cause difficulties when checking polarity and AC wiring on boats.

A good example is putting a regular refrigerator or microwave on to a boat. I have had to often take the case off of the item, or otherwise get into the AC incoming wiring, and disconnect the neutral from the case. If you have reverse polarity then the appliance case would be hot.

So if you are installing land use appliances, put your ohmmeter on the neutral and the ground plug and see if they are connected internally.

Another reason European standards are far, far superior than US LOL.

I do not believe that you can find today a modern US appliance that has neutral bonded to pprogram protective ground ( or with less than 10000 ohms in between, according to my measurements). Otherwise the GFI will trip. I would love to see evidence to the contrary. I hope you will make me learn something!
By the way; I have tested this in real life by taking all my US appliances to countries where there are whole-house GFIs and did not use an isolated transformer.

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[rwidman]

Originally Posted by exMaggieDrum

One thing I have been intending to add: appliances not designed for marine use often have the neutral and ground bonded within the unit. ..........

That is incorrect. That would defeat the purpose of a separate neutral and ground.

US code requires the neutral and ground to be connected together only at the service entrance or origin. In a typical house this is in the electrical panel. At a marina, this is at the service entrance to the marina. On a boat that is disconnected from shore power, if there is a source of power on board (genset or inverter), the neutral and ground are connected together at this point and disconnected from each other when shore power is restored.

[mitiempo]

I don't think reverse polarity will harm any appliance. I do think it can be an issue for an inverter with an AC input pass through as the inverter (when inverting) connects neutral and earth, although I haven't checked this.

With single pole breakers when a single circuit is turned off if hot and neutral are reversed the circuit is still hot. Most smart people would either turn off the main double pole breaker or unplug the boat entirely before working on the circuit but some may not. North American regulations are designed to protect those with the least knowledge.

[rwidman]

Originally Posted by mitiempo

I don't think reverse polarity will harm any appliance..

The point is not harming appliances, the point is, we want to avoid hurting people. The reasons an electrical system with the polarity (hot and neutral) could harm people have reversed have been covered already in this thread.

[thinwater]

Just hysterical. And scary.

Why do people post about things like electricity who lack real understanding? It is irresponsible and dangerous. Just listen when outside of your expertise. I don't work with euro standards and won't comment on them. US rules and practice should be well known within the US, but it's amazing how many posters slept through science class.

Yeah, I saw a guy get juiced once by unfused 460/3; he didn't know what he was doing and made a basic mistake.

[rwidman]

Originally Posted by thinwater

Just hysterical. And scary.

Why do people post about things like electricity who lack real understanding? It is irresponsible and dangerous. Just listen when outside of your expertise. I don't work with euro standards and won't comment on them. US rules and practice should be well known within the US, but it's amazing how many posters slept through science class.

Yeah, I saw a guy get juiced once by unfused 460/3; he didn't know what he was doing and made a basic mistake.

I agree with you but I have to say that being awake through science class doesn't qualify one to work on electrical systems or even make statements except in a very basic way.

Becoming a skilled electrician takes several years of study and apprenticeship. Can you do basic installations and repairs without this? Yes, but by carefully following books or diagrams.

[NorthernIsland]

Well, if you take US build boat to Europe and connect to no- polarity AC socket, based on your statement above, people will get hurt. Obviously not the case in practice.

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[four winds]

Re. My post number 82. Exactly as I said.

Post number 83 read it wrong.

Post number 84 read it right.

Like many here I know a little bout lectricity. But discussing it with sailors from around the world is problamatic.

Originally Posted by four winds

On my old US boat factory wiring....


....

White AC neutral goes to the shore AC neutral only. And I assume is connected to earth ground somewhere out there.

The differing standards between EU and US is difficult to understand in this discussion. Primarily, I feel, because of misuse or misunderstanding of the terminology used. Wire color, neutral, safety ground, hot, floating, etc.

[letsgetsailing3]

Originally Posted by K_V_B

My main assertions were simply that:
a) It is possible to wire a boat to a sandard so that reverse polarity at the dock is not an safety concern.
b) Solving a problem at a fundamental level is better than a workaround. A reverse polarity indicator is a workaround to a fundamental issue in wiring standards.

a) is a proven fact. The proof is in the current literature for boat wiring standards from both sides of the Atlantic. This is not just some EU thing.
b) is my opinion. You can debate on that. But I do see some people agree with me there.

Your assertion was "polarity doesn't matter". That was incorrect in general, and incorrect for the OP.

You then went down the rabbit hole about standards, when either standard, when applied correctly, will work.

[four winds]

Good comment here for this thread:

Quote not mine....

...........If you ever expect to learn anything, you're going to have to start reading posts with the idea of understanding them, not with the idea of how to argue with them.

[deblen]

Originally Posted by four winds

Good comment here for this thread:

Quote not mine....

...........If you ever expect to learn anything, you're going to have to start reading posts with the idea of understanding them, not with the idea of how to argue with them.

100% true!!! Well said!
This thread started by a boater in Maylaysia having a rev. pol.lite on.
The thread has enlightened me on the differences in electrical grids & "grounding" methods around the world.
I have now been convinced that if I ever took my boat outside of N.A.,I best not rely on current N.A. NEC/CSA/ABYC codes to keep me safe.
Conversely,non-N.A. recreational vessels should not necessarily count on their homeland standards to protect them elsewhere either.
I hope to see a worldwide std. for boats in near future-and that std. enforced & adhered to by marine electricians,so that,those boaters who are sensible enough to employ one,know it is being done right.
/ Len

[deblen]

Originally Posted by deblen

Earthing system - Wikipedia, the free encyclopedia

Earthing is done differently in different countries around the world.
The neutral is not necessarily earthed,in the N.A. way.
OP asked about Malaysia. If the earth conn. at the marina is bad,the neutral will float,in the marina.
If you plug your boat into this,with it's green & neutral commoned,as it should be,& connected to the water(engine earth),the Rev Pol lamp could light.

Safest & simplest bet in foreign countries is a 230V battery charger IMHO.

Originally Posted by thomm225

The example isn't talking about the bulb but the socket.....(as far as a person getting shocked are worse if in water etc)

again:

By contrast, a lamp socket connected to a reversed-polarity receptacle will have a ‘hot’ (ungrounded) screw-shell that is cycling at significant voltage to ground, while the spring-tab at the base will be ‘neutral’, and at zero volts to ground. Someone touching both the reverse-connected screw-shell and something grounded would become a conductor for significant current moving from 120V RMS ‘hot’ to zero volt ground

Originally Posted by thomm225

This thread pretty much tells you to avoid posts on a forum and read the book instead.

Lots of pure jackassery being posted here........

And yes I made up the word jackassery just like some of the posters made up their facts on electricity.

Agree-too many "opinions" based on "I think", "that's how we do it ,or, always did it".
I have "read" & have the papers to back it-but limited to our N.American system.
I stand by my post that I have learned enough,from this thread,to read up on systems elsewhere in the world,& to gain enough respect for the dangers of assuming my boat would be safe anywhere.
The above Wiki article is a good start on understanding that there are differences.-,if you leave N.A.

jackassery is more common than common sense,I find. Cheers /Len

[thomm225]

Originally Posted by deblen

I stand by my post that I have learned enough,from this thread,to read up on systems elsewhere in the world,& to gain enough respect for the dangers of assuming my boat would be safe anywhere.

I hope you are listening to the right posters then .................good luck.