Rocker Switch on Main Battery Panel

I am adding an additional circuit off the main battery panel in the aft sect of the bilge on my 2004 34' Pilot Sedan. Just thought I would pass along the info on the panel breakers. They are made by Carling Switch......here is the picture.
For those on yahoo its
Part# CO1-B0-14-650-33B-C
F.L. Amp 50
Max Volts 70
Hertz D.C.
Delay 14
Trip Amps 62.5
I was able to order it from Flounder Pounder Marine OEM Surplus obsolete boat parts for 39.90

I am a little curious why you are adding a 50 amp breaker back there. That aft panel supplies loads that never should be turned off, like bilge pumps. The other panel with typical Airpax breakers is at the aft of the cabin.


David

I am running a separate line up to a switch panel on the dash for the electronics I just put in. I don't like that all of it is off the helm breaker in the cabin. I would like to be able to pick and chose at various times what electronics I have running. This way I have a dedicated electronics line with a circuit breaker protecting the wiring that keeps to the 3% voltage drop, a switch panel that has its own built in circuit protection, and a way to turn on and off the different electronics. It's probably overkill but the dash panel that I am putting in has the ability to have a max 45 amps, so in the future I will be able to add or change things around and not have to worry about exceeding wire rating. After saying all of that I am more than willing to take suggestions. If I go another route I can always keep the breaker as a spare.

I won't be able to look at my boat for a few weeks, but if the interior panel has a 30 amp breaker and #10 wire feeding it, then I agree with you. But if it is a 50 amp breaker with #8 or so then you could just tie in to the load side of the 50 amp breaker and feed you sub panel from there.


The only electronic item that draws a lot of current is the autopilot hydraulic pump and it is less than 10 amps. Everything else will be less than 20 amps total off of that main DC breaker. So 30 amps at 16' round trip length on 8 gauge gives you less than 3% drop.


David

I believe that it is a 50 amp breaker with 8 wire at the cabin panel. But if I were to go that route why not just tap off the positive post under the dash panel? I could go from the positive post right to the switch panel.

This is where I get start to get confused. and when confusion sets in, I tend error on the side of caution.
To measure the length of the circuit for the voltage drop don't I need to factor in the run from the batteries to the cabin breaker panel as well as the distance to the helm and back to the batteries to correctly size the wire for the voltage drop? Or can I just measure the voltage at the panel with a digital multimeter to ensure I have adequate voltage?
Currently everything is connected to the helm breaker,
Fore and aft ceiling lights
2 windshield wipers and I am planning to add one for the center window
Blower
Raw water wash down pump
2 fans
Nav lights
Courtesy lights
Trim Tab Controls
12 volt receptacle
Vhf radio (max draw 6 amps)
Autopilot (according to Raymarine 15 amps)
9" display 2 amps
7" display 1 amp
Radar 2 amps
Have not hooked up a stereo as of yet
All of this is why I figured on running another circuit. I would rather be safe then sorry,
Your thoughts on this David or anyone else reading this?

The reason I suggested picking up at the load side of the 50A (yay!!) breaker at the aft cabin is that you don't need another big breaker to protect the wire going to your sub panel. The 50A does that.


Yes, all of that stuff you listed adds up to a lot of amps, but electricians accept that not all will ever run simultaneously. I stand by 10A for an autopilot and 20A for everything else that could reasonably be expected to run simultaneously. My 50A breaker has never tripped and I have all of the stuff you listed (minus a 9" display- why two on a Pilot?)!


My NextGen 3.5 KW genset won't run every AC load simultaneously either, but I get by ok. But come to think of it, neither will the 30A shore power cord.


David

I wanted to go with 1 12" monitor but it was actually cheaper to go with a 9 and a 7. This gave me redundancy and it allowed me to go with both traditional sonar and the new downvision. Each mfd has a different capability. I am planning to use the boat for scuba diving hence the downvision. But back to the original subject, mostly I am just trying to do this as correct as possible and not have it look like to much of a hack job. I have almost 20 years as a fireman and I have seen the devistating effects of a fire. Add to that my wife and my grandchildren are onboard constantly which means no matter what the situation I am responsible for their safety and anyone else on my boat for that matter. So I am just trying to "do it right" the first time around and have one less thing to wonder or worry about.
I am going to be back on the boat in the morning to confirm the breaker and wire size that is there. Just to be clear, are you referring to the helm breaker or the dc main breaker? I am not ruling out your suggestions and I do appreciate your time, effort, and input.
Kevin

OK, to be clear. In the main cabin on the aft bulkhead is the AC and DC panels. The DC panel has a main breaker, a 50A you say. It powers all of the others, including the helm breaker near the bottom left. That supplies power to the helm panel and each device has switches and button breakers.


So what I am suggesting is to tie in to the load side of that 50A main breaker to feed your subpanel.


And there is nothing unsafe about powering multiple breakers and devices from that 50A breaker as long as the breakers are sized for the wire that they protect. The NEC understands and allows it.


Think about it, if you plugged in three 1,000 watt heaters into three outlets in your house that were all on the same 15A breaker, you would trip that breaker which is what it is designed to do: protect the 14 gauge wire.


David

I will double check the breaker and wire size and go from there. What you are saying does make sense.