Shore Power

[maddiemutt]

I am looking to install a simple shore power system on my 250 explorer.  What I would like to do is install a water proof power inlet to be able to connect a locking power cord from the dock supply.  On board there is a dual bank battery charger which I would like to hookup permanently.  The only other circut I want is a receptacle in the cuddy to run a tv, dvd player, coffee pot, etc.  My question is from the shore power inlet what would I need to do to hookup these two circuts.  I don't feel the need for any complicated system but want to be sure I have a safe system.  Thanks for the help.

P.J.

[seabob4]

It can be done.  From your hull inlet, run 10/3 cable to a DPDT 30A breaker.  Install a ground and neutral bus close by, dump the neutral to the bus, the 120VAC ground to the ground bus, tied in to your boat's 12V DC ground (to provide a ground path).  Wire your outlet (use a GFCI) and your batt charger to the 30A breaker and you're good to go...a way I DON'T recommend!

Now, this is not the safest way, as your 30A will protect the circuits, but if your appliances are rated at 10-15A, it won't trip before they get fried.  So do it the right way and get a small 120VAC distribution panel with dedicated breakers for your branch circuits.  Between the hull inlet and the breaker panel, etc., plan on spending $300...but it's worth it!

[maddiemutt]

Thanks seabob for the help.  I looked at and I am considering this route.  I will install a waterproof hull inlet to plug the shore cord into.  From there I am looking at a BLUE SEA SYSTEMS 30 amp double pole main breaker.  From there I will go to an BLUE SEA SYSTEMS AC distribution panel with up to (8) 15 amp breakers to run to the individual circuts.  I only have plans for three circuts but will have the future space if needed.  My only question now is how to ground the system.  It appears from the wiring diagrams that the system will be grounded back through to the dock by way of the AC Safety Ground leg which is part of each circut, the breaker panel, the main breaker and the cord.  If that were the case I would not have to do any grounding through the boat's DC ground.  Is this correct?  

Thanks again for pointing me in the right direction.

P.J.

[seabob4]

PJ,
We, and all other builders, tie in the 120VAC ground to the 12VDC ground.  That way you truly do have a "ground to earth" (albeit water).  Often there are "issues" with electrical supplies around water.  Better to have a direct connection through your engines' zincs than to have stray current running around your boat's AC circuits... :(

[maddiemutt]

Seabob,
Thanks again.  I will ground through the DC ground like you advised.  Can't wait for the weather up here to break so I can get started.

Best Wishes,

P.J.

[gran398]

Should you need it, I have a brand-new Hubble 50 Amp lead, cheap from a friend who sold his boat.

Just PM.

[maddiemutt]

Seabob,
Will I need to install a galvanic isolator between the inlet and the main panel?  The boat will only be in fresh water.  Thanks

P.J.

[seabob4]

Seabob,
Will I need to install a galvanic isolator between the inlet and the main panel?  The boat will only be in fresh water.  Thanks

P.J.

I would strongly recommend it...stray currant is stray current, fresh or salt.  Salt is a better conductor...

[maddiemutt]

Seabob,
I have selected to use a Blue Sea Systems Panel.  It has a main 30 amp breaker and (3) 15 amp breakers for distribution to branch circuts.  It comes fully prewired with a ground bus and a neutral bus.  Am I correct that I will tie all branch circut neutrals to panel neutral bus and all branch circut grounds to the panel ground bus?  I then will run a #10 wire from the panel ground bus to my DC ground.  If this is correct I will not have to install additional ground and neutral buses nearby to the panel.  Thank you.

P.J.

[seabob4]

Seabob,
I have selected to use a Blue Sea Systems Panel.  It has a main 30 amp breaker and (3) 15 amp breakers for distribution to branch circuts.  It comes fully prewired with a ground bus and a neutral bus.  Am I correct that I will tie all branch circut neutrals to panel neutral bus and all branch circut grounds to the panel ground bus?  I then will run a #10 wire from the panel ground bus to my DC ground.  If this is correct I will not have to install additional ground and neutral buses nearby to the panel.  Thank you.

P.J.

PJ,
You are absolutely correct.  However, I would use 8GA as your ground tie-in, just for safeties sake.  Assuming your DC ground bus is relatively close, the cost would be minimal.  Now some may ask why use 8 when 30A service uses 10 to feed the panel?  Just my personal preference...

Sounds like you've got it all under control!

Bob C

[GoneFission]

Sounds like you've got a good plan going.  Don't forget to install a reverse polarity indicator if your panel does not already have one.  It's amazing, but some docks and marinas still may not have correct polarity.  This makes the neutral side hot - not good for you or your boat!!  Use a 30 amp twist lock connector for the boat, but remember also to buy a 30 amp to 15 amp adaptor so you can plug in to a regular outlet if you need it.  

[seabob4]

Sounds like you've got a good plan going.  Don't forget to install a reverse polarity indicator if your panel does not already have one.  It's amazing, but some docks and marinas still may not have correct polarity.  This makes the neutral side hot - not good for you or your boat!!  Use a 30 amp twist lock connector for the boat, but remember also to buy a 30 amp to 15 amp adaptor so you can plug in to a regular outlet if you need it.  

All excellent pieces of advice...

[maddiemutt]

Thanks Cap'n John.  This panel does have a reverse polarity light built in.  Give me about a month to make sure Spring is actually coming and I will post some pictures when I am finished.

Best Wishes,

P.J.