Shore Power - Reverse Polarity ... Please Help

[ndgambella]

i recently bought a 1987 sea ray 250 sundancer, great condition... when i plug into the shore box i went to the circuit panel and pressed the "test" switch,,, the reverse polarity light came on... now it only lights up when i press the test lever,.. is that a RP issue or would the light go on by itself if it did have reverse polarity.. bc other people ive seen post with this problem have said that the light goes on by itself...

thanks in advance

[btrayfors]

It should come on by itself.

However, do yourself a favor and get a simple polarity tester. They are very inexpensive (like $9.00 with free 1-day shipping), and are very handy to have on hand to check all your outlets, and to test when you plug into a new marina.

Here's one on eBay:



Bill

[ndgambella]

nice, that is handy.... thanks for the quick response

[US1Fountain]

Bought a tester like that one that also checks your GFI's from Menards. Handy little tool.

[Unicorn Dreams]

Welcome Aboard CF

With tester check the shore power outlet 1st to see where the polarity issue is. You or them. if then advise the marina and they can come out and check wires in the box...

[Lancerbye]

Welcome aboard. The test switch is to prove that the indicator lamps will light when there is a fault. The fault you will get is not a reverse polarity ( since that doesn't exist in AC) but an indication that either your boat or the marina has been improperly wired. Hot is on the neutral.

[doug86]

The test button is there to prove that the light works, not to activate a test for correct polarity. If the boat has a reverse polarity problem, the light comes on all by itself.

[btrayfors]

Actually, these little testers check for at least five fault conditions:

1. Open Ground
2. Open Neutral
3. Open Hot
4. Hot & Ground Reversed
5. Hot & Neutral Reversed

And, some check your GFCI's as well.

Some of these faults can be dangerous to equipment (like a dropped or open neutral) and some can kill you (like the "reverse polarity" condition #5).

AC (whether from shorepower or an inverter or generator) is nothing to fool with, particularly on a boat.

Bill

[GordMay]

Originally Posted by doug86

The test button is there to prove that the light works, not to activate a test for correct polarity. If the boat has a reverse polarity problem, the light comes on all by itself.

NOT NECESSARILY!

The total impedance of polarity indicating and protection devices connected between normal current carrying conductors (grounded [white] conductor and ungrounded [black] conductor) and the grounding conductor shall not be less than 25,000 ohms at 120 volts, 60 hertz at all times.

Another strategy (NOT recognized by the ABYC) is to install a Momentary “Push to Test” Pushbutton in series with the RPI. The has the effect of entirely disconnecting the RPI from the circuit, until you test for polarity (by pushing button when you first connect to shore power). Several manufacturers used to use this strategy.

Accordingly, it's impossible to tell the purpose & function of the PB, without examining the circuit.