Wiring for shore power

ric · **Posted:** Sat Dec 07, 2013 3:23 pm

Aside from the plug on the side of the boat which is pretty straight forward, I was looking into this automatic transfer switch:
http://www.defender.com/product.jsp?pat ... id=2360037

I can plug my house battery bank/inverter into the switch and when I plug into shore power, it automatically transfers the 120v load off the inverter and I can power that down. The plan is to actually install a remote battery switch controlled in the cabin (future).

Question goes, if I want to power a charger off the shore power that's powered on whenever shore power is plugged in, I just basically connect the charger before the ATS?

PS, this is what will eventually control my inverter's power supply via. a switch in the cabin.
http://www.amazon.com/Blue-Sea-Systems- ... B0016HRUPE

It's winter off season and it's time to finish this whole A/C and 120v house power project! If I ever sell this boat it's going to make someone's dreams come true lol

Surface Interval · **Posted:** Sun Dec 08, 2013 6:58 pm

Ric, the automatic transfer switch is a good thing to have to automatically switch between sources of power. There are some considerations to be aware of though. If you lose shore power the transfer switch will revert back to your house battery system and inverter if they are on. If you are away or not aware of this and you have higher electrical loads turned on you will go through your house batteries pretty quick. Another possible issue is that this transfer switch is limited to 110 VAC and 15 amps input from shore power. Most standard shore power plugs for boats this size are capable of 30 amps. This means that the transfer switch will limit to how many electrical accessories you can use on shore power. Look at the amperage or wattage each appliance or circuit draws and keep this in mind when planning or using your system. Since your battery bank is 12 volts and you have a 110 Volt AC system, and since inverters are never 100% efficient, you can use a 10 to 1 comparison to roughly estimate for amperage draw. If a 110 VAC appliance draws 5 amps, it will need approximately 50 amps at 12 volts from your battery bank. This is just a rough estimate and you can mathematically calculate loads, but keep in mind that you may have higher surge loads during an appliance's start up.

You mentioned a single bank battery charger in your other post. One question I would have is.....why not have a two bank charger to keep both the engine and the house battery banks charged? Any boat connected to shore power at the dock is getting both battery banks charged/maintained all week between trips, unless the charger is switched off.

Wiring the charger into the shore power side of the transfer switch should work fine. Use a switch and circuit breaker. If the charger is wired after the transfer switch you have a situation when using the inverter where battery power goes through the inverter to power the charger to recharge the very batteries that are providing power. This is a waste of power and may also cause the inverter to be overloaded and show a fault reading. In this case you would have to turn the charger off when using the inverter. Just make sure to follow recommended practices, wiring schematics, and grounding procedures for safety and outdrive corrosion reasons.

ric · **Posted:** Mon Dec 09, 2013 12:20 am

The only thing the house battery bank runs is the A/C system and in the future the TV via a cigarette lighter outlet in the cabin. The TV currently runs off the boat bank but it's draw is so low (24in LED HDTV) that I would have to run the TV for nearly a week straight to get a no start situation on the boat.

The inverter came with the A/C system as a package. Roughly 48-50 amp draw when running the compressor, which runs approx. 20 minutes per hour when it's mid 80's outside. With a 230ah bank (around 200 usable) it equates to roughly 12 hours of A/C in the summer. On a night like tonight when it's in the mid 60's it's just going to circulate air every 15 or so minutes which just spins up the air fan, not the compressor or water pump. Amp draw is minimal.

On a weekend out on the water (sat/sun) with one overnight, it's plenty of power to sleep comfortably even in the hottest florida summer nights. What I use it mostly for is on my local lake to get out of the sun and chill out watch football or play cards with buddies when it's 95 out.

ric · **Posted:** Mon Feb 10, 2014 12:00 am

Okay I'm starting to get my ducks in order to finish my wiring project. I want to get the AC built in before May.

Found a better transfer switch that handles it all:
http://gpelectric.com/products/30-amp-transfer-switch

Breaker panel:
http://www.defender.com/product3.jsp?pa ... id=1324806

Remote battery switch for house bank (so I can turn on/off inverter in cabin, save power):
http://www.defender.com/product.jsp?pat ... id=1508894

Shore Power connector:
http://www.defender.com/product.jsp?pat ... id=1357589

Battery Charger:
http://www.defender.com/product.jsp?pat ... id=1982743

Anything else electrical that I might need to order? Other than some more marine rated 120v a/c wire?

www.iFourWinns.com

Wiring for shore power

Who is online