[C320-list] Reversed Polarity Light

[T. Scott Thompson]

My experience is that this is almost always a false alarm, especially if
plugged into a shore power connection that has tested OK in the past. 
False alarms can be a sign that something else is wrong, however.  Read
on for more info...

The reverse polarity light is detecting a voltage difference between
neutral and ground.  This can be created by improperly wired shore
power, but can also occur if you are running an AC load and something is
causing a voltage drop on the neutral line between the panel on the boat
and the ground/neutral connection back on shore somewhere.  For example,
a bad or weak connection somewhere in the neutral circuit could be
causing some resistance.  But a heavily loaded circuit with undersized
wiring can cause this too (although in theory that should trip a breaker
somewhere).  It sounds like that might be the cause in this case. 
Advice:  Don't push the amperage limits.  And check that there is no
sign of arcing or overheating at the shore power connections.  You may
have fried something.

I think you can also get this symptom with a bad ground connection under
some circumstances.

Assuming there isn't actually a hot/neutral reversal, the light should
go out completely if you turn off all AC loads, including battery
charger, because then neither the neutral nor ground should be energized.

For more information on reverse polarity indicators and "false alarms"
see the following articles

http://www.bluesea.com/Article_detail.asp?Section_ID=290&id=295
http://www.bluesea.com/Article_detail.asp?Section_ID=290&id=296

Scott Thompson
Surprise, 653 
------------------
T. Scott Thompson
sthompson at toad.net




Quoting bruceheyman at cox.net:

> Calvin,
> It sounds like the duplex that you are pluged into has the hot and
> nutral flipped.  That or a home made extension cord has the black and
> white wire flipped.
> Bruce
> Somerset 671 SoCal
> Sent via BlackBerry from Cingular Wireless  
> 
> -----Original Message-----
> From: Calvin Liebel <ccliebel at telus.net>
> Date: Sat, 03 Feb 2007 19:00:53 
> To:Catalina 320 Owners <c320-list at catalina320.com>
> Subject: [C320-list] Reversed Polarity Light
> 
> Went down to the boat to check her out after another NW Pacific 
> winter 
> gale.  Seems this winter will set a record for the number of storms
> we 
> have experienced this winter.
> To help keep the boat dry I run a small electric heater and  fan in
> the 
> main cabin and a dry-air heater in the vee berth.  To day  when I 
> flipped on the water heater breaker  I noticed the Reversed Polarity
> 
> light came on very faintly.   I noticed the speed of the fan drop
> when I 
> switched on the water heater. Thinking the load from the  water
> heater 
> and space heater might be too much for the 20 amp service, I switched
> 
> everything off .  With only the water heater on, the Reversed
> polarity 
> light still came on faintly.   Has anyone experienced this or know
> what 
> I should check?
> Cal Liebel
> Prairie Dream #1056
> 
> 
> 

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