Reverse Polarity??

[svHyLyte]

Michael,

We had exactly the same problem when we had to replace our zenon pulse phase amplifier for the helicoidal tachyon field antenna. Yep--We had to replace all the phaser shift connectors with new to beat the mid-pulse field polarity reversals.

FWIW...

s/v HyLyte

[SV Someday Came]

Originally Posted by svHyLyte

Michael,

We had exactly the same problem when we had to replace our zenon pulse phase amplifier for the helicoidal tachyon field antenna. Yep--We had to replace all the phaser shift connectors with new to beat the mid-pulse field polarity reversals.

FWIW...

s/v HyLyte

Oh, beat me with a Whisker Pole, force me to weather, and make me wear wet socks.

You got me!

Michael

[Fearnow]

Now I'm having the same problem. Nothing has changed at the marina. The only thing I did was plug in an electric heater for a few hours and the next day the light was on. I came on a few months ago, briefly, but no problem since. I checked all the wires at the panel and the main ac breaker.
Any other ideas? Will a loose connection somewhere cause this?

[AnchorageGuy]

Originally Posted by Fearnow

Now I'm having the same problem. Nothing has changed at the marina. The only thing I did was plug in an electric heater for a few hours and the next day the light was on. I came on a few months ago, briefly, but no problem since. I checked all the wires at the panel and the main ac breaker.
Any other ideas? Will a loose connection somewhere cause this?

The answer to your question is, yes it can. But I strongly suggest you get someone very familiar with marine electrical systems to have a close look at your system as soon as possible. This isn't something to take lightly or try and troubleshoot over time on an online forum. The consequences can be serious. Chuck

[Ex-Calif]

Originally Posted by Fearnow

Now I'm having the same problem. Nothing has changed at the marina. The only thing I did was plug in an electric heater for a few hours and the next day the light was on. I came on a few months ago, briefly, but no problem since. I checked all the wires at the panel and the main ac breaker.
Any other ideas? Will a loose connection somewhere cause this?

Is this the reverse polarity light on the charger or is it a separate RP light/circuit.

Things are always changing at the marina - corrosion etc. in the shore box for example.

The quickest test is to plug the shore power into a different shore box, making sure it is a different supply circuit and not the same leg of the shore power. Then try a different shore plug/cable.

This may isolate shore box vs. boat vs. cable.

The next step is to isolate all the A/C circuits on the boat one at a time. Activating each circuit one at a time to see if you can isolate the circuit causing the fault (you state the heater might be suspect).

So far this can all be done without a meter or opening stuff up.

After that you are likely going to have to get a meter out and start metering stuff. This can kill you and you may want to let a pro step in depending on your experience level.

If you don't have it get Nigel Calder's book, "Boatowners Mechanical and Electrical Manual."

Read and reread the chapter on reverse polarity and then read the table on A/C electrical circuit troubleshooting. If you can't grasp it get a professional sparky involved.

BTW - if the RP light is on and the charger is still supplying power to the boat (and hasn't auto shut down) you must assume that neutral is hot right now.

There is a condition that will result in what you describe. Because reverse polarity is checked by potential from Neutral to Ground. Under a high load situation (heater) a high resistance in the Neutral circuit - all the way back to the shore box can create a voltage drop in the Neutral leg that changes to potential between Neutral and Ground that is read as a reverse polarity.

In this case you must make sure that the wiring to the high load device (heater) especially the Neutral leg is adequate sized and clean and low resistance. A high resistance in the shore plug conneciton can do this also - clean all shore power conections and inspect the shore power plugs and receptacles.

The most common failure in shore powere is plugs, receptacles and connections.

[sailinglegend]

Originally Posted by Ex-Calif

....There is a condition that will result in what you describe. Because reverse polarity is checked by potential from Neutral to Ground. Under a high load situation (heater) a high resistance in the Neutral circuit - all the way back to the shore box can create a voltage drop in the Neutral leg that changes to potential between Neutral and Ground that is read as a reverse polarity......

This is often the cause of the polarity light coming on, but the key is how bright is the light? If it's only dim then there maybe only 5-10 volts between N and E. This will change as more boats turn on more kettles or more heating. This indicates bad wiring in the marina installation. If it's full brightness then you have the full reverse polarity situation and the N wire is actually Live.

[CharlieJ]

Just to be clear: the reverse polarity condition is caused when the line (Hot, L, usually black) conductor and the neutral (N, usually white) are reversed.

Here are two excellent references from Blue Sea Systems that describe the condition and the monitoring system:
https://www.bluesea.com/resources/84
https://www.bluesea.com/resources/90
The ABYC paragraph numbering has changed but the content is, by and large, the same.

[AnchorageGuy]

Originally Posted by CharlieJ

Just to be clear: the reverse polarity condition is caused when the line (Hot, L, usually black) conductor and the neutral (N, usually white) are reversed.

Yes that is one cause but not the only cause. As Ex-Calif stated, "There is a condition that will result in what you describe. Because reverse polarity is checked by potential from Neutral to Ground. Under a high load situation (heater) a high resistance in the Neutral circuit - all the way back to the shore box can create a voltage drop in the Neutral leg that changes to potential between Neutral and Ground that is read as a reverse polarity."

A short, too small wiring in the circuit from the dock to the boats system or a serious voltage drop coming from the service will all illuminate the reverse polarity light. Chuck

[CharlieJ]

AnchorageGuy-
I absolutely agree! I just wanted to start him off on the basics. In my experience RP usually occurs because of either some electrical work that just occurred on the vessel or on the pier. "Just occurred" being the operative phrase.

[Ex-Calif]

Originally Posted by CharlieJ

AnchorageGuy-
I absolutely agree! I just wanted to start him off on the basics. In my experience RP usually occurs because of either some electrical work that just occurred on the vessel or on the pier. "Just occurred" being the operative phrase.

With the info given it does not appear any maintenance work was done recently. He also noted that he observed the fault during or after the cycling of his heater.

While troubleshooting should be thorough to make sure the prime suspect appears to be the heater circuit condition.

[Fearnow]

I found the problem! When the charter company installed the new shore power electric connection, they did not tighten the neutral wire. It finally came loose, causing the RP light to come on. I wish I had checked that first, before tearing everything else apart on the boat.

[CharlieJ]

Yup. ALWAYS check the most recent work first.


Sent from my iPad using Cruisers Sailing Forum

[rwidman]

Originally Posted by CharlieJ

Just to be clear: the reverse polarity condition is caused when the line (Hot, L, usually black) conductor and the neutral (N, usually white) are reversed. ...............

Exactly. That's the definition pf "reverse polarity".

Now back to the original post - Is the problem on my boat or with the marina wiring?

OK, Turn off the breaker on the power post, unplug your shore power cable and plug it into a different outlet (on a different pedestal if possible). If the problem goes away, it's the marina's power outlet. If not, it's your boat's wiring or your shorepower cord. Try a different shorepower cord. If the problem goes away, it's the cord.

[Fearnow]

I have herd of instances where the whole pier is screwed up. Check with other people on the pier, before tearing apart your boat.

[Ex-Calif]

Originally Posted by Fearnow

I found the problem! When the charter company installed the new shore power electric connection, they did not tighten the neutral wire. It finally came loose, causing the RP light to come on. I wish I had checked that first, before tearing everything else apart on the boat.

Wow. That was potentially very dangerous. Shame on the installer.

Yup - recent maintenance.

Like my grandma used to say, "Dan go check out the last thing you f**ked up first."