[C38] melting shore power connector

[Don Strong]

The dockmaster at Emery Cove Yacht Harbor, Diane, where Patrick and I 
are berthed, told me that arcing and corroded shore power service is the 
only cause of boat fires in her long experience at this large marina. 
Mr. Matheson at the marine electronics business by Diane's office also 
emphasized to me the risk of these old 120 V systems. He has a rouge's 
gallery of melted shore power installs in his office. As I posted 
earlier, it isn't only the plug that can melt and cause fires. Old, 
corroded 120V wiring inside the boat can also arc, heat up, and cause 
fires. A third marine engineer recommended that I make sure that the 
wiring inside the boat was up to the task of 120V alternating current. 
His words, "...important to remember that the circuit breaker might not 
protect the boat wiring from arcing, overheating, and fire." He 
convinced me to look for corroded shore power wire inside the boat. I 
found it. 25 year old green and blackened 120V wiring inside the boat.
Don

On 6/6/11 1:56 PM, Chuck Finn wrote:
> Patrick,
> That would be wishful thinking!  You still only work off the one 15 
> amp breaker.   This makes your problem look even more like arcing as 
> you clearly are not overloading the 30 amp circuit if you are not 
> using the water heater!  Remember the power cable is rated for at 
> least 30 amps and you clearly are not coming close to that number.
>
> All the best,
> Chuck Finn
> Mighty Quinn #114
> Great Lakes
>
> On 6/6/2011 4:46 PM, Patrick Harpole wrote:
>> Chuck,
>> I "never" use my water heater.....get hot water only when engine is 
>> running. Does that mean I have 3000 watts?
>> I assume I don't.
>> Patrick
>> ----- Original Message ----- From: "Chuck Finn" <charles at finn.ws>
>> To: "Catalina 38 Listserve" <listserve at catalina38.org>
>> Sent: Monday, June 06, 2011 11:59 AM
>> Subject: Re: [C38] shore power
>>
>>
>>> 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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>>
>>
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-- 
Donald R. Strong
Professor
Dept. of Evolution and Ecology
University of California, Davis 95616