Refrigerator on Shore Power (Newbie Q)

[SailingErrant]

New (to me) Catalina 310 almost one year ago, but still plenty of newbie questions. In fact, each time I solve a mystery two new ones pop up. I've worked my way through the manual, but it seems to overlook lots… Thanks in advance for any help you can offer. Or links to back-posts I've missed?

I seem to only be able to operate the refrigerator on battery power even when I'm plugged into shore power. In other words, if I am plugged into shore power, I still need to have the Perko switch turned to battery number one, battery number two, or all in order to get the refrigerator to run. Is that normal? Am I missing something? Shouldn't the refrigerator be able to run on shore power when I have the "AC On" circuit switched on?

And a related question: is it only possible to recharge the batteries when the engine is running? Or can I recharge them from shore power as well? If it's possible, I haven't figured out the secret formula.

 

[JK_Boston_Catalina310]

Welcome to the group.

First thing, go to my blog and download all of the manuals I have there. Under "The Boat" page I have posted a lot of manuals for the Catalina 310 near the bottom. I have others that I haven't put up there do to space so don't hesitate to ask a question if there is something you are looking for.

To answer your question on the refer, the stock refer unit on the Catalina 310 is a 12 volt only system. We don't have one of those fancy systems that can run on 12 volt or 120 volt. So being plugged into the shore power doesn't help you other than you can run your battery charger non-stop.

To answer your battery charging question, the alternator does charge the batteries but there is a big but here. The stock alternator is 40 or 50 amps (can't recall which at the moment) but the alternator is regulated on the unit itself and not temperature compensated. So the end result is that you probably aren't getting more than 20-30 amps to the batteries. The factory setup also has that charge being carried by undersized wires for part of the run as well so that could reduce this further. Our boats use about 40 Amps per day. So will need to run the boat for 2+ hours to put back your usage. What type of batteries you have, how good they are and other factors will all play a roll.

The first thing to do is actually check if the alternator is working. Get a digital multimeter, set it to voltage 20 mark and touch the appropriate posts to the battery terminal while the engine is running. You should see something in the high 13s to low 14s.

Another thing you need to know is that the way Catalina setup the boat, the Perko switch also directs the charging of the batteries from the alternator too. So you won't be charging battery #1 if the switch is set to #2. This is one of the first things I changed.

Good luck and don't be afraid to ask questions here.

Fair winds,

Jesse

 

[rpwillia]

Battery Charger Switch

As you refrigerator is 12V only, if you leave it on at the dock you also need to turn on your battery charger. Your battery charger is one of the switches on the AC portion of your panel to the left.

You did not ask, but you water heater is also heated by the coolant in your engine through two hoses. The water heater is also on the AC portion of your power panel, but you should use the electricity only if you need hot water and leave it off the rest of the time (sometimes bad things happen).

 

[wufibugs]

Same deal as my Hunter. So I added a dedicated a/c plug on the port side of the aft berth and installed a dorm reefer there. Keep it running on shore power so the cold beverages and some condiments are there to welcome me on weekends. Plug goes dead when dock cord is unplugged. The unit stays cold for a couple of days at which time things can be transferred to 12v unit.

 

[SailingErrant]

Many thanks, everybody. Slowly demystifying this vessel. And [mostly] loving the adventure...

 

[seadaddler]

My H-36 has the Ref run on 12 volt only also and just to let you know I added a AC/DC
transformer and 1 year later it stop working and was not cheap.
I leave my ref 24/7 at the dock so I have cold drink all the time.
I added solar and never need to use the charger.
Nick

 

[Stu Jackson]

Congratulations on your fine boat. You're no longer a newbie!

The information you'll gain here is priceless and will save you tons of time.

One of the important things that Jesse has shared is a resource of a ton of material that will save you looking all over the internet.

Many of us provide handy links to other resources as well, and most boat systems are NOT boat-specific. Electrical and plumbing systems on your boat and mine are essentially identical. OTOH, we both have M25 series engines, but your M25XPB is much different than my M25, so the best place I've found information on the entire internet about yours is right here on the C310 forum.

Please be aware of these resources on our C34 website and make use of them:

Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html

"101 Topics" lots of stuff all in one place http://c34.org/bbs/index.php/topic,6437.0.html

 

[Alansails]

Welcome and also please consider joining Our Catalina 310 association to support those who support us! You also get a Discount for BOATUS and Mainsheet magazine comes with your enrollment.
The benefits far out weigh the cost, on many levels!
Again welcome, further information can be obtained from our treasurer, Curt Sawyer : Curtis.sawyer@gmail.com
This has benefited me greatly, I am still learning new things!