[C320-list] Electrical Question

[John Frost]

Kurt

The 2003 wiring diagram that came with my MKII says the power goes from the
transom plug, through a 30 Amp circuit breaker there to the polarity test
light switch and another 30 Amp circuit breaker at the electrical panel. I
understand the your tripping this circuit breaker is what trips the GFCI, so
what it feeds is the key.
My diagram shows that it feeds a power on light and three 15 Amp Circuit
breakers, one for the outlets, one for the water heater and one for the
battery charger. I would turn all three off and test your 30 Amp breaker
again. If the GFCI remains on, bring the 15 Amp circuits on one at a time
'till it trips the GFCI. Then you will know which circuit to inspect. 

In the unlikely event that the GFCI still trips with all three small
breakers open, I would unplug power, disconnect the output wire on the 30
Amp breaker plug back in and test again. That will tell you if it is in the
short wiring, the power on light, or the breaker itself.
  

Happy Sailing!

John
2007 C320MKII
Hull 1118
Guntersville, AL




-----Original Message-----
From: c320-list-bounces at lists.catalina320.com
[mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Kurt R.
Budelmann, M.D.
Sent: Sunday, July 24, 2011 11:45 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Electrical Question

John,

Thanks for the input.  But do you know what is connected on our boats with 
only the AC main breaker turned on and all other breakers off?  Do you mean 
disconnecting the positive or "hot" cable from every breaker in the panel 
and reattach one at a time?

I hear a click from the AC to DC switch device.  Other than that I can not 
determine what other circuit /device should be active.

Does your marina use GFI breakers on shore?

Kurt
----- Original Message ----- 
From: "John Frost" <john at frostnet.net>
To: <C320-List at Catalina320.com>
Sent: Sunday, July 24, 2011 11:02 AM
Subject: Re: [C320-list] Electrical Question


>A GFCI works by comparing the current going out on the hot lead to the
> current returning on the neutral.
> If they are not equal, it assumes that some of the current is going to
> ground, possibly thru a human, and trips the breaker.
> http://en.wikipedia.org/wiki/Residual-current_device
>
> Because all circuits have some amount of leakage to ground, it allows up 
> to
> 5 milliamps to exist before it trips.
> Your tripping when you hit the reverse polarity switch is not surprising 
> as
> that puts a small current to ground.
>
> The tripping when you turn on your main circuit breaker is not good 
> however.
> That means you have some leakage to ground between your main circuit 
> breaker
> and the loads that it feeds.
> I would disconnect all loads that the circuit breaker feeds, turn on shore
> power, turn on your main circuit breaker and reattach the loads one by 
> one.
> When you get to the problem circuit, the GFCI will trip.
> Then examine that circuit carefully.
>
> Good luck, and be careful.
>
> Happy Sailing!
>
> John
> 2007 C320MKII
> Hull 1118
> Guntersville, AL
>
>
>
> -----Original Message-----
> From: c320-list-bounces at lists.catalina320.com
> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Kurt R.
> Budelmann, M.D.
> Sent: Sunday, July 24, 2011 8:00 AM
> To: C320-List at Catalina320.com
> Subject: [C320-list] Electrical Question
>
> My marina has GFI circuit breakers for my shore connection.  When I plug
> into shore power and flip on the main transom 30 amp breaker all is well.
> But, when I either flip the test polarity switch to make sure it is 
> working
> or I flip the AC panel breaker with every other breaker off, the GFI 
> shore
> breaker trips.  Neither of my two breakers trip.
>
> I plugged into a non-GFI shore outlet (I swapped it in the breaker box on
> shore)  and everything works well.
>
> I believe the issue is a ground problem on the boat as the current I draw
> when running everything except the water heater is less than 1 amp when
> plugged into a non-GFI shore breaker.
>
> Has anyone else experienced this problem and any suggestions on how to fix
> this?
>
> I hired the marine electrician from the largest nearby marina and he 
> claimed
> that it is a problem with boats and GFI breakers.  His facility does not 
> use
> any GFI breakers and they have hundreds of boats, some even over 100 feet.
>
>
> __
> Kurt Budelmann
> Everwind, Catalina 320 #1035
>
>