[C38] shore power

Chuck Finn charles at finn.ws
Tue Jun 7 08:19:51 EDT 2011


Dave,
The original configuration as far as I am aware is the main, 30 amp 
breaker and two, 15 amp breakers working off the main.  The two 15 amp 
breakers are usually located directly below the 30 amp breaker.    A 30 
amp system would require at least #10 wire throughout the ship, which 
would require a very different 120 volt outlet (it would look like the 
shore power outlet).  Wire size is mandated by breaker size as the wire 
must be able to carry the current that would trip the breaker without 
melting or burning.  The only code exception I am aware to this was NEC 
allows 15 amp outlets to be fed from a 20 amp breaker (politics), but 
our boats were wired with 20 amp outlets from a 15 amp breaker (good).
If you don't have the 15 amp breakers, I personally would be quite 
concerned....

And thanks for the tip on dielectric grease on the cord!  I use it on 
the batteries, etc. but never made the connection regarding the AC 
side.  Duh!

Chuck Finn
Mighty Quinn #114
Great Lakes

On 6/6/2011 11:46 PM, D McC wrote:
> Chuck,
> On hull# 148 we have the single 30A breaker that services the entire 110V AC system on the boat. The 110V AC system is the original.
> ~Dave
> <><><><><><><><><><><><><><><><><><><><><><><><><><><>
>
> Common Sense is a rare gift from the Gods.
> Most people have only technical training!
>
> <><><><><><><><><><><><><><><><><><><><><><><><><><><>
>
> The gods do not deduct from man's allotted span those hours spent in sailing.
>
> <><><><><><><><><><><><><><><><><><><><><><><><><><><>
>
> When in doubt, try the vice You haven't tried before!
>
>
> --- On Mon, 6/6/11, Chuck Finn<charles at finn.ws>  wrote:
>
>> From: Chuck Finn<charles at finn.ws>
>> Subject: Re: [C38] shore power
>> To: "Catalina 38 Listserve"<listserve at catalina38.org>
>> Date: Monday, June 6, 2011, 11:59 AM
>> Patrick,
>> Our main breaker is 30 amps, but this can be very
>> misleading.  This is a 30 amp breaker, which feeds the
>> two, 117-20 volt, 15 amp breakers.  There are two, 117
>> volt circuits in our boats.  Usually, your battery
>> charger and everything else is on one and your water heater
>> is on the other.  The water heaters we commonly have
>> are 1500 watt, which pretty much maxes out the one circuit
>> breaker.  So, you get the other 15 amps to work
>> with.  Now, you might think that gives you  15 x
>> 120=1800 watts available, but is really about a max of 1500
>> watts  (80-90% of max is considered relatively
>> safe).   So, now you can add things up:
>>
>> microwave:   600 - 1000 watts.
>> hair dryer: 400 - 1000 watts.
>>
>> What makes me write this is the wire outlet that
>> melted.  This I believe is the "load" wire and the
>> melting on the plug looks more like an "arcing" issue. 
>> I think  Steve S. and Tom T. are better at this than I
>> am, but there are two ways I know we get arc
>> melting.   First is not shutting off your
>> circuit breakers before unplugging, but I am guessing you do
>> this.  Second is the problem caused by cords getting
>> stretched as the boat moves on the dock.  I see this a
>> lot at the marinas I visit.  Folks simply plug their
>> boats in like they would a vacuum cleaner at home, with no
>> attempt to secure the plug.  Yes, there are cords that
>> have a threaded coupler, but I cannot see that yours is
>> one.  Regardless, I have a rule that both ends of my
>> electrical cord have a "wrap" around some secure point on my
>> boat and the dock (I use the large winch).  I believe
>> many marinas want you to take a wrap around the the power
>> pedestal to protect their outlets and this is a rule at my
>> yacht club.  Steve S. has an article all about this by
>> the way!
>>
>> Boat US reports this is a major issue regarding insurance
>> fires on boats.  Perhaps we should be discussing this
>> as well?
>>
>> Chuck Finn
>> Mighty Quinn  #114
>> Great Lakes
>>
>>
>> On 6/6/2011 1:51 PM, Patrick Harpole wrote:
>>> A few days ago I asked for help determining loss of
>> shore power.  Thanks for
>>> the advice.  Turns out one terminal of the female
>> connector to Marinco cable
>>> melted down.  Local hardware sold connector for
>> about $20.  Works fine.
>>> Harbor Freight sells (about $20)device which plugs
>> into wall then plug
>>> appliance into other end.  It reads power
>> consumed by appliance.  I believe
>>> I was using too many amps, for example, hairdryer.
>>> Patrick
>>> "Blue Eyes"
>>>
>>>
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