Electrical System write up

Everything related to San Juan 21 and the Class Association
Ben G
Posts:24
Joined:Tue Apr 05, 2011 6:02 pm
Re: Electrical System write up

Post by Ben G » Sun Jun 10, 2012 9:30 pm

An SJ21 will sink if swamped or left moored with a leak. I've read the accounts of these events and the subsequent salvage via tire tubes and a compressor. I think positive flotation was the main reason my parents' first boat back in the 70's was a Catalina 22. Their club also had an SJ21 fleet which caught my eye and some day,I thought, I'd like to have one -- that day was 35 years later!
Ben Gibson/'77 Mk-II/#1864/cruiser/Greenville, SC

Condre
Posts:16
Joined:Fri Aug 05, 2016 2:16 am

Re: Electrical System write up

Post by Condre » Fri Jan 06, 2017 4:44 am

Kuriti;

Any idea what the max amp draw for your system is? I was thinking about a sixty amp system with extra heavy wire, like 2 awg, for the battery leads. But my battery is in a compartment next to the transom. The 2 awg boat wire to run from there to the cabin is kind of pricey. Is that why your battery is in the cabin?

kuriti
Posts:243
Joined:Tue Sep 13, 2011 12:48 am

Re: Electrical System write up

Post by kuriti » Mon Jan 09, 2017 1:19 pm

My battery is inside the cabin because that is where the electrical panel is and I keep my gas can in the lazzerette. I can't remember what gauge wire I used, but no need to greatly overdue it, that will only add expense. I used Nigel Calders book as a resource, but you can find recommendations for gauge size based on the run and expected draw online. I went one size larger than the recommended just to over build. Make sure it is tinned wire and use appropriate connectors for marine. The wire from the battery to the bus should be short and thick, but the wires to the components should be based on run and draw. Planning for a 60 amp draw is way overkill. My battery is only 50 amps to start with. My motorcycle amp that runs the speakers is my biggest draw at max 5 amps. With LED lights on, I might get to a 5 amp draw at a given point, but probably more like 2-3 while playing music.

Electrical circuits are confusing for sure, study up and you will get it. Buy your wire for the runs in bulk from eBay and buy your battery positive/negative thick wires from a local auto store since you shouldn't run it farther than a foot or two.

Tim_M
Posts:14
Joined:Sat Nov 28, 2015 10:06 pm

Re: Electrical System write up

Post by Tim_M » Sat Apr 01, 2017 5:56 am

My boat does not have an electrical panel and I'm going to put one in this year. Where did Clarke put the panel on boats that came with them?

Roamer
Posts:37
Joined:Tue Sep 08, 2015 6:00 pm

Re: Electrical System write up

Post by Roamer » Sat Apr 01, 2017 4:02 pm

I have read in this forum that the designer said the boat will NOT float when swamped. No reason to avoid opening up the hull liner to provide extra storage. If you take that much water into the cabin, it's headed for Davy Jones' Locker...

edit: oops... didn't read page 2... this has already been mentioned...

kuriti
Posts:243
Joined:Tue Sep 13, 2011 12:48 am

Re: Electrical System write up

Post by kuriti » Sun Apr 02, 2017 1:45 pm

Tim, my panel is on the starboard box at the head of the coffin berth. Mine is a MK II

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