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Old 29-06-2014, 21:02   #46
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Re: Circuit, Wire, Fuse Size

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Originally Posted by Maine Sail View Post
#4 Most bilge pump circuits will have two fuses, one at the battery (to protect the circuit wires) and one at the bilge switch (to protect the pump)....
Why? Assuming you are putting the bilge pump on a dedicated circuit, and using 14 ga wire for a 3 amp load, one fuse/breaker at the distribution panel accomplishes the need. Why have a second fuse in a bilge where it may be damp and corrosion could be a problem? If there is a problem, interrupting the circuit at the panel takes care of all protection requirements. In-line fuses complicate troubleshooting and serve no purpose that I am aware of when there is only one device on the circuit that is already protected by the fuse/breaker on the panel.
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Old 29-06-2014, 21:08   #47
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Re: Circuit, Wire, Fuse Size

You wrote:

1a - This is my attempt to show the internal circuitry of the 1-2-all switch. If you zoom in you should see that the output is actually the center "dot" 2 pairs of dots are connected to each other inside the switch - As the pointer rotates the contacts are made and broken appropriately (I think)


Why bother? There are three POSTS on a 1-2-B switch and four POSITIONS. KISS. Don't label it ALL, it's simply 1-2-C (common) POSTS that you wire to. That's what a wiring diagram is for, not to show the switch positions.
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Old 29-06-2014, 21:34   #48
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Re: Circuit, Wire, Fuse Size

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Originally Posted by St. Elsewhere View Post
<snip>
Why have a second fuse in a bilge where it may be damp and corrosion could be a problem?
<snip>
Agree but my bilge switch came with a fuseholder built in.

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You wrote:
[I][COLOR=Blue]

Why bother? There are three POSTS on a 1-2-B switch and four POSITIONS. KISS.
Cuz I'm a bit OCD and anal. All the components in the schematic software have to be "built" and grouped. The included library is very lacking.

There are lots of conversation around here - usually - with newbies - about how stuff works.

I figured while I was at it I would show how the switch makes and breaks. May end up being able to use the drawing in the future.

Agree, it's totally unnecessary.

Also the longer I look at the schematic the more I see can be improved for clarity and the guy who follows me. Example is the battery fuses aren't depicted right - Both will be non-post mounted. The bilge switch actually has a fuse in the switch.

As an amateur who will likely only do this one schematic - ever - There is a a balance between clarity and simplicity.
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Old 29-06-2014, 22:40   #49
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Re: Circuit, Wire, Fuse Size

On the subject of mechanical robustness, may I recommend the boat cable, which has the two 14 gauge conductors and a protective white outer layer. It's more robust than two separate conductors.
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Old 29-06-2014, 23:33   #50
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Re: Circuit, Wire, Fuse Size

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On the subject of mechanical robustness, may I recommend the boat cable, which has the two 14 gauge conductors and a protective white outer layer. It's more robust than two separate conductors.
I am considering "some" of that for "spider links" - like pairs to cabin lights.
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Old 30-06-2014, 13:33   #51
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Re: Circuit, Wire, Fuse Size

Dan-
"Oh - I still don't think one of my root questions has been answered and I actually am still a bit confused.

Wires in a bundle will have higher resistance due to interference with each other. They will also get hotter. That's why you size up."

Not really. With low power DC lines, you won't get an significant heating caused by more wires in the bundle. What happens is that every other wire is an additional HEAT source and INSULATOR and that drives up the temperature of the bundle, as opposed to having separate runs all in free space. So it is strictly a thermal concern.

When you mention the help wanting to just lop off all the old wiring? That can be a great idea, a total gut rehab. IF they are sure they can replicate and replace everything. Otherwise it can be a radical problem as you try to figure out "Gee, how was this run?". Especially when there are coaxial cables or other special wires involved. I'd say better to lay in the new wires, transfer each circuit over, and then only rip out the old stuff after you know everything is working on the new wiring.

I wouldn't run the cabin lights and the masthead/nav lights on the same forward run though. Nav lights, like the VHF and the bilge pump, really should be on their own so there is no chance of something else taking them out. And cabin lights, inevitably, get no respect and you'll find there's a reason they are often fused portside and starboard, in two separate runs.
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Old 30-06-2014, 17:31   #52
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Re: Circuit, Wire, Fuse Size

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I wouldn't run the cabin lights and the masthead/nav lights on the same forward run though. Nav lights, like the VHF and the bilge pump, really should be on their own so there is no chance of something else taking them out. And cabin lights, inevitably, get no respect and you'll find there's a reason they are often fused portside and starboard, in two separate runs.
Each service will be a separate circuit. Regards cabin lights I am probably going to do a forward and aft circuit, Why run wires to the mast base then back to the companionway opening?

All the wiring is out - I worked the schematic some more last night - as I think about equipment I keep remembering "one more circuit" - Last night I realized I forgot the ST40 stuff and someone gave me a Garmin GPS panel mount at a boat swap meet that I am considering mounting.

I have to nail the schematic in the next day or so as I really need to get the equipment order in.
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Old 30-06-2014, 17:47   #53
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Re: Circuit, Wire, Fuse Size

From the "spend less money on wiring" point of view, fore/aft cabin light splits makes sense. But functionally...if you need to work on something at night, or worse on a moonless night while underway...having power off to one side of the cabin still gives you good enough lighting to work on the other side, and vice versa. It's handy to have light and power less than six feet away, for whatever reason.

As opposed to splitting it fore and aft, when the dead "half" may be too long for light to really get in from the other half.

Depending on your layout, that may not be an issue. Just something to consider, how well you will manage on "just half" depending on how you split the halves.

Of course if the head & v-berth are "just" on the one half side anyway, that may not matter at all. It may work out to be effectively the same thing either way.
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Old 30-06-2014, 18:06   #54
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Re: Circuit, Wire, Fuse Size

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It's handy to have light and power less than six feet away, for whatever reason.
Head lights work very well. In fact they are far superior to working with light that is coming from behind you or dim light that isn't shining directly on the work.
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Old 30-06-2014, 18:11   #55
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Re: Circuit, Wire, Fuse Size

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Originally Posted by FlyingCloud1937 View Post
One thing you need to remember.

All critical circuits need their own dedicated circuit each. So anyt load that is required to operate the vessel be on it's own dedicated circuit. Ie no ganging Nav lights with any other cicruit, VHF dedicated, radar, GPS, engine electrics.

I even go as far as separate circuit for anchor light, then I lead the the nav lights switch to a gang fuse, so all running lights are fused separate. That way if you have a fault in one of the running lights, all others still work. .......
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Yup - When I got the boat the steaming light was on the same switch as the nav lights? I guess the PO always motored at night. To free up a switch I ganged the instrument power with the instrument lights - not ideal.................
Yes, I agree that all critical circuits require separate protection. With the nav lights I took a slightly different approach. Each light (stern, port & stbd) all have individual fuses which are then wired to an individual pole of a four pole switch. That way, each light has it's own pole inside the switch.

However I have "ganged" the compass light to the same switch using the "spare" fourth pole. Of course, it also has it's own fuse. I have found that I need the compass light on anytime I am using the nav lights however YMMV.
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Originally Posted by Ex-Calif View Post

Final schematic isn't done and if I have to have 12 switches I will have to find the space even if it means rearranging the cabin build. Actually with the 3-panel I could have 15!

I am adding a stereo, foredeck light and want the cabin outlets switched so I still have some homework to do.

When is enough switches enough? Never - LOL...
What switches are you using?

When I first started my re-wire, I looked around at almost every commercial, recreational boat, marine, industrial, home use, hobby etc etc switch I could find.

In the end I used Eaton MIL-S-3950 sealed toggle switches, not because they might be the best but because I knew they more than good enough. I could have looked forever trying to find something better. They were also easily obtainable from aviation outlets like EDMO or Aviall etc. I'm sure you are familiar with these switches Eaton / Military Grade Switches - 8501K4 - Switches - Toggle - Allied Electronics
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Old 30-06-2014, 18:24   #56
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Re: Circuit, Wire, Fuse Size

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Originally Posted by hellosailor View Post

Depending on your layout, that may not be an issue. Just something to consider, how well you will manage on "just half" depending on how you split the halves.
I am already overthinking way to many things - LOL.

The cabin is 20 feet long and 7 foot beam - the halves aren't that big but I get your point.

Quote:
Originally Posted by DeepFrz View Post
Head lights work very well. In fact they are far superior to working with light that is coming from behind you or dim light that isn't shining directly on the work.
I have a couple of these - brilliant! LED, red and white modes.

Quote:
Originally Posted by Wotname View Post
Yes, I agree that all critical circuits require separate protection. With the nav lights I took a slightly different approach. Each light (stern, port & stbd) all have individual fuses which are then wired to an individual pole of a four pole switch. That way, each light has it's own pole inside the switch.

However I have "ganged" the compass light to the same switch using the "spare" fourth pole.
4 fuses for 4 bulbs - I get it but that might be overkill. I have wire that can take 25a and an LED stern light. If any of the wire runs to nav lights goes over 5a I have other problems to worry about.

Ganging the compass light makes sense.

Quote:
Originally Posted by Wotname View Post
Of course, it also has it's own fuse. I have found that I need the compass light on anytime I am using the nav lights however YMMV.

What switches are you using?

<snip>

In the end I used Eaton MIL-S-3950 sealed toggle switches, not because they might be the best but because I knew they more than good enough. I could have looked forever trying to find something better.

<snip>
I have an Attwood 6 -switch panel and the 3-panel I bought is also Attwood. I have considered the modern looking Blue Sea panels etc. But I have to make some money saving decisions - in the end I still have a $18k boat.

Those Eaton switches - Wow! I don't love my boat that much - LOL...

I am going to order a second 6 switch to make sure I have room to grow.

http://www.amazon.com/Attwood-Toggle...ttwood+switsch
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Old 30-06-2014, 18:40   #57
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Re: Circuit, Wire, Fuse Size

Quote:
Originally Posted by Ex-Calif View Post
.......
4 fuses for 4 bulbs - I get it but that might be overkill. I have wire that can take 25a and an LED stern light. If any of the wire runs to nav lights goes over 5a I have other problems to worry about.
....................
Those Eaton switches - Wow! I don't love my boat that much - LOL...
.....
One day we will have to trade stories about who is most OCD, anal and such like, maybe over some

Of course with four fuses, I also had to run independent circuits to each light

The keel might fall off, the sails blow out, the mast might topple, the engine seize up but my electric's will never fail until the last electron is pushed out of the cold dead fully sealed AGM along the Mil Spec white wire (you know the ones)...

Good luck with the re-wire / re-build!
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