[C320-list] AC reversed polarity light

[John Frost]

>From your description of the circuit, either of 3 problems could cause the
light to illuminate:

1. A reversed hot and neutral. That could be at the dock (you have ruled
that out), in the cable (Very unlikely unless you have recently changed
connectors) or on the boat (Very unlikely since it used to work fine).

2.A reversed hot and ground at the same locations (very dangerous but very
unlikely since nothing has changed and you are not getting shocked) 

2. A bad connection in the neutral circuit, most likely on the boat or power
cable connectors (very likely). A corroded connection in this "return leg"
causes the neutral on the boat to be energized (as compared to the ground)
by the current that has gone thru your AC loads because it can't all get
back to the dock outlet. I would start with a careful inspection of the
power cord connectors at both ends and the outlets that they plug into. They
go bad frequently. Look for heat discoloration or corrosion. You might also
try a neighbor's cord. If a visual inspection doesn’t turn it up, you will
need to test the voltage between safety ground and the neutral on both sides
of each connection with an AC volt meter, with all of the AC boat loads on
(maybe plug in a heater to give a high load). Note that while the bad
contact is probably in your part of the circuit, it could also be in the
dock wiring. Be careful, 120 volts can easily kill. 

Happy Sailing!

John
2007 C320MKII
Hull 1118
Guntersville, AL

PLEASE: STOP E-MAIL HARVESTING
Protect your friends and family: 
Do not give my e-mail address to any person or web site.
Delete my name and e-mail address before forwarding this e-mail to anyone. 
Use BCC when sending to multiple addresses.
Thank you! 



-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Scott Thompson
Sent: Wednesday, July 07, 2010 8:37 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] AC reversed polarity light

Thanks Irv.  I suppose I should keep one of those on board.

I know that the problem is not on the dock.  I have this problem at all 
dockside outlets now, including ones that work fine for other people and 
worked fine for me not long ago.  It's clearly something between the 
dockside outlet and the AC panel on the boat.  I'm looking for some way 
to track the specific faulty part or connection.

To you electrical experts out there:  Looking at the AC wiring diagram, 
the reverse polarity light appears to be wired to detect a voltage 
present between the neutral (white wire) input side of the main AC 
breaker on the panel and the AC ground bus bar behind the panel.  What 
failure of my wiring would cause a voltage to appear there consistently? 
  It isn't clear to me why an open circuit on either neutral or ground 
would cause either one to show up as "hot", which is what you would 
expect with an actual polarity reversal.

I have no inverter, and the factory stock AC installation.

Scott Thompson
Surprise, #653

Irving Grunes wrote:
> All,
> See :
> http://www.tequipment.net/IdealReceptacleTesters.asp
> for and electrical tester to check the outlets on the boat.
> If the oytlets are bad, then the dock receptacle is probably bad.
> Irv Grunes
> #851
> 
> On Wed, Jul 7, 2010 at 8:13 AM, Scott Thompson
<surprise at thompson87.com>wrote:
> 
>> Thanks.  That's where my suspicions lie.  Is there some way to test? And
>> does anyone know a part number or source?
>>
>> Scott
>> Surprise, #653
>>
>> vpweikel at comcast.net wrote:
>>
>>> Scott,
>>>
>>>
>>> Had the same reverse polarity issue a few years back.
>>>
>>>
>>> Turned out to be the shore plug on the stern.
>>>
>>>
>>>
>>>
>>> Paul Weikel
>>> Second Chance
>>> #361
>>>
>>> ----- Original Message ----- From: "Jim Sweet"
<jamesweet at frontiernet.net>
>>> To: C320-List at Catalina320.com Sent: Tuesday, July 6, 2010 8:17:15 AM
>>> Subject: Re: [C320-list] AC reversed polarity light
>>> Had the same issue on our old Pearson 332.  Also had an intermittent
>>> flicker in the reversed polarity light.  Turned out to be a bad power
cord.
>>> Jim Sweet TGIF (Thank God It Floats) 901
>>> ----- Original Message ----- From: "Scott Thompson" <
>>> surprise at thompson87.com> To: "Catalina320.org"
<C320-List at Catalina320.org>
>>> Sent: Monday, July 05, 2010 9:38 PM Subject: [C320-list] AC reversed
>>> polarity light
>>>
>>>  On our recent cruise we found that the reverse polarity light came on
>>>> when we tested the AC hookup in 2 different marinas, and then again
back on
>>>> our home pier.  Since there was no indication of improper wiring at any
of
>>>> these locations, and since we had no trouble at the home pier at the
start
>>>> of the trip, I assume that the problem is somewhere in my boat or power
>>>> cord.  The power cord passes a simple end to end continuity check on
each of
>>>> the three conductors, and there is no sign of any shorts.  Does anyone
have
>>>> suggestions on what to look for next?  It's occurred to me that perhaps
I
>>>> need to replace the shore power connector on the transom.  It looks OK,
but
>>>> after 11 years, maybe the weather has taken its toll.
>>>> My recollection is that faults other than reverse polarity can cause
>>>> these kinds of symptoms but I do not remember the details.
>>>> --
>>>> Scott Thompson Surprise, #653
>>>>
>>>
>>>
>> --
>> Scott Thompson
>> Surprise, #653
>>

-- 
Scott Thompson
Surprise, #653