Wiring question for behind-helm fuse block(s)

S

Sunbeam

Active member
Edited to add: A friend happened to be looking over my shoulder and so I now think I have the answer; but perhaps this will still help someone else with my same question (and of course correct me if this is wrong). I'll put my "answer" at the bottom.

I'm preparing an order for "goodies" so that I can upgrade the wiring leading from the lazarette up to the behind-helm area. Currently, I have one "thinnish" wire heading up there that goes to one fuse block (stock setup).

So, I was planning to to run a #6 red cable from the lazarette up to the behind-helm area to supply two new fuse blocks (because I want more fuse locations than a single 12-fuse block will provide). Then run a #6 black wire back to the negative bus in the lazarette.

My question cropped up because I realized... wait... if I'm going to have two fuse blocks I have to supply them both somehow (one #6 cable is enough to carry the loads for both in terms of gauge). So how do I handle the wiring at the fuse block end? Do I just run the main feed cable to one of them, and then to the other one.... in series.... somehow? What exactly do I do with the positive and negatives "in the middle"? I get that one positive cable runs forward, and then one negative runs back to the laz, but am not sure how to handle the "in betweens" to connect the two fuse blocks.

This is the type of blocks I plan to use, btw:

fuse_block.png

Edited to add: So okay, I think I run the red feed wire up to the positive terminal on the first fuse block, then a small red "jumper" from there to the positive terminal on the second fuse block, where it can dead-end. And I do the same thing with a black cable to the negatives. So they are in parallel. This looks obvious once I saw it drawn out, of course! :wink: I'm probably fuzzy headed from trying to make up my shopping list of the various lugs, crimps, ring-terminal sizes, and etc!

Thanks,
Sunbeam
 
Sunbeam, I would treat each fuse block equally, and make the jumper a 6 also. The common point for the supply cable and the jumper is just a connection point. The jumper and the long run of cable are the same supply, and share a fuse at the source, yes? If you step down to a smaller diameter jumper, then you would need a fuse inline to protect that wire.
 
Dave,

Thanks for your input. I had already planned to use the same #6 cable for the jumper; however, I see I said "small" jumper, when I should probably have said "short" jumper (of course by nature a jumper is probably always short). Anyway, I'm glad you said something (even though I had already planned to use #6 because you really couldn't tell by the way I wrote it).
 
Captains Cat":11r2d5v4 said:
And, Sunbeam, we are all sure you meant "in parallel" and not in "in series".
Click to expand...

Well actually, in my original post (which is in regular type), I did say "in series," because I wasn't sure what to do (hence my posting the question!). I had imagined it as a big circle. But then in my edit, which is in italics, I said "in parallel" because by then I understood that was the right way to do it (a friend had been reading over my shoulder and drew it out for me, after which it made sense). I thought about just deleting the thread, but then I figured that perhaps someone else would have a similar question and find the thread helpful. And plus I always learn from comments by experienced Brats.

I think I'm going to have fun "tidying up" behind the helm (albeit cramped fun).

Now I have to decide between two 12-position fuse blocks (ah, symmetry), or one 12 and one 6 (more compact). Right now I think I have a 10-position one (original) with eleven things on it. So the first 12-position block will cover that. Then, I'm really not sure if it would be usual to end up needing an additional 12 fuses as things grow (i.e. 24 total), or if 6 would be enough (for 18 total). Comments?
 
For now I'm going to stick with two (fuse blocks, that is :lol:). Just mulling whether to go with two 12's, or a 12 and a 6. Not that I can't fit two 12's, but on the other hand, space is at a premium behind the fiberglass "cover" there, a 6 is physically smaller, and there is no sense having tons of extra fuses I won't ever use. I really just don't have a mental image of how many things I might add that will require a fuse position there. But I'm sure I'll add something(s), hence the second fuse block now. Right now I will have 11 used.

So in summary, it's a matter of having 7 spare fuse positions vs. 13 spare fuse positions. If it's likely 13 will be needed in future, then it's easy: Two 12's. If that's preposterous, and 7 will clearly be enough, then I'll use the smaller 6 for the second block.
 
That's one nice fuze panel. I need to do the same on my wiring mess...I tried to get by using just the factory fuze panel but ran out of space...

I had not thought about running a secondary feed line though...the one the factory installed looks pretty good for what I need to power..

My new electronics (Raymarine E140 and attachments) all now have separate power feeds where the old system (Raymarine C80) had everything feed from the unit itself...so I now need to install a switched accessory circuit

Joel
SEA3PO
 
I have been doing some behind the helm reorganizing myself. Here's one possible consideration:

Primarily because of unwanted battery draw from some unswitched electronics (Heading sensor and Depth Sounder Black Box), I put all electronics on one fuse block with its own switch. I'm really happy with it. I used a 6-fuse block because that allowed consolidation and isolation of the electronics. From what I could learn, trying to separately switch part of a larger fuse block was going to be complicated and beyond my meager abilities.

As it is, by my count I now have 8 fuses on the rocker switch panel on the front of the helm, and 20 fuses available (3 blocks of 8, 6 & 6) on the back side. I have 6 open spaces left spread among the 3 blocks. I have designs on one of them already.

I agree it's hard to have too many fused blocks! So I'd say go with the bigger second block unless for some reason you could contemplate a smaller grouping to be treated as a unit, and could put in a 12 and a 6 now and another 6 later.

And don't forget to label. :)
 
Bill,

That's good info, thanks. You now have me thinking two 12's for sure, and perhaps one 12 and two 6's... yet another option :D As set-up when the boat was new (and still now), I don't believe my switch panel (that faces me when I'm at the helm) has any fuses. I believe those items go on to use positions on the fuse block (so they are part of my "eleven used" at the moment). So probably another good reason to have more block positions.

My electronics do shut off with the main battery switch, as-wired, but I don't know if the "not shutting off with switch" is characteristic of the newer ones? I will likely be upgrading plotter/radar etc. in the relatively near future, and I would want/expect them to shut off when I shut everything else down. If that were not normally the case, then I'd probably want to do something like you have with the separate 6-block unit. Do you know if that's "normal" for newer electronics or just a quirk of your wiring that it was easier to adjust to than to change?

I've been labeling everything as I go along.... ahh, it's nice to have things tidy and labeled, isn't it.

Sunbeam

PS: I'm in for the full catastrophe as I just ordered a windlass, too :shock: :D
 
Sunbeam":15h6hjda said:
Bill,

. . .
My electronics do shut off with the main battery switch, as-wired, but I don't know if the "not shutting off with switch" is characteristic of the newer ones? I will likely be upgrading plotter/radar etc. in the relatively near future, and I would want/expect them to shut off when I shut everything else down. If that were not normally the case, then I'd probably want to do something like you have with the separate 6-block unit. Do you know if that's "normal" for newer electronics or just a quirk of your wiring that it was easier to adjust to than to change?. . .

Sunbeam

PS: I'm in for the full catastrophe as I just ordered a windlass, too :shock: :D
Click to expand...

Here's a link to some discussion on the subject:
http://www.c-brats.com/viewtopic.php?t=20786
(Some of the picture links don't work because I removed pictures as the project was complete. At this point, they don't add anything to the discussion, anyway.)

I don't know what's "normal." I think that in my case (a 7 year old Furuno system) the lack of a separate switch for the Heading Sensor and the Black Box are a "feature." It sounds like other brands may be switchable out of the box, or at least come with a recommendation for a switch at the time of installation. I didn't install my electronics originally, but I have looked at the installation manual and didn't find any mention of installing a switch.

Re the windlass: I don't know what make/model you're going with, but I just recently upgraded my Lewmar V700 by adding a (wired) remote switch and replacing the rinky-dink helm switch with a solenoid. Some pictures starting here: http://www.c-brats.com/modules.php?...ame=gallery&file=index&include=view_photo.php I think Lewmar includes this heavier duty switch now, but don't know for sure. When I removed the original, I was shocked (no pun intended) by how flimsy it was.
 
Thanks for the added info and links. You know, what I may do for now is just get one 12-fuse block (which will cover me for now with one extra), but make sure to leave room for another(s). That way I can wait and see if it should be one 6, one 12, two 6's, or etc. It's taking me awhile to shake the "I have to order everything now before I am away from civilization!" mentality I had on a previous boat.

I went for the Lewmar 700 horizontal windlass. Bit more of a "chunk" on the foredeck, but I'm used to horizontal windlasses, so I wanted that type. It does come with a "contactor" for behind the helm, which I gather is a relay of sorts, and more heavy-duty than older setups (I was clued in to that by reading threads here; this forum is endlessly helpful). I also splurged on a 3-button wireless remote (a Lewmar accessory). That extra expenditure can be "blamed" on Jay from Hunky Dory :wink, as after I saw his in use at Powell I just had to have one.

Of course ordering it is just the beginning. Now I'm checking stock on wire, lugs, crimps, epoxy, fillers, Weld Mounts, etc. etc. to see what else I need to order. Then.... measuring about - oh fifty times - before making big holes in the boat :smilep

Whee!
 
Sunbeam,

Unless there is not room for another 12, why would two 6 terminal fuse boxes be preferred? One twelve eliminates one #6 jumper, compared to two six terminal boxes. I assume the boxes all have 10-32 hardware where the supply lugs will go.

Only reason I can think of for two sixes is that you can separate wiring into "functional" groupings, placing all electronics on one, all pumps on another, etc., making identifying which fuse goes to what a bit easier, assuming the fuse box locations might be hard to see in rough conditions or poor lighting. Labels at each fuse location may be a little easier to see if the boxes are separate instead of one 12. This seems like a pretty fine point to me, but your layout may dictate better than anything we might speculate upon.
 
AstoriaDave":3812u2h9 said:
Sunbeam,

Unless there is not room for another 12, why would two 6 terminal fuse boxes be preferred?
Click to expand...

Ha, this will teach me to try to be less wordy (which never works anyway :D).

So, I have 11 fuse positions used now. I want to use the Blue Sea fuse block type I showed above. These don't come any larger than 12 positions, so I think I'll end up with more than one.

One 12-position is a certainty, to cover the 11 fuses I use currently.

For the second block I could go with a 6, or another 12. The only reason for a 6 was that it's more compact, and if I don't need more than that, well, it's a fairly cramped space.

Then I was introduced to the idea of making the second "block" two 6's in case I might want to isolate one for the electronics (apparently some do not get shut down with the battery switch, although the ones I have now do). You can see where this was mentioned a few posts above in the thread.

Since a single 12 will give me an extra position for now, I think I've decided to just go with the that for the moment, while making sure to leave a space for more (a 6, a 12, or two 6's). Presuming any new electronics I may get do shut off with the battery switch (as my current ones do), then I would not have any need for two additional 6's (vs. one 6 or one 12).

Hope that clarifies,
Sunbeam
 
I have a second fuse block under the galley top, against the rear bulkhead. It feeds the cabin LEDs, cockpit lamp, 3 12v aux plugs, and the demand faucet pump.

These systems now have shorter DC runs. The source feed wires now each conduct less current.

This is one reason to add a second fuse block.
 
What else you may want to add, and may require additional fuses:
Fans. I have two in the V Bunk area, and two on the windshield.
Extra lights: LED "night lights" red in the cabin--one near the helm, and one over the galley and table.
LED lights for the cockpit. "spreader" type of lights to face aft.
Some lights for each side--LED--small type or spreader type.
A circuit for a forward light for docking--either mounted on the bow pulpit, or magnetic mount on the anchor.

Extra circuilts for more than one multi function display--one for Radar/GPS sounder, or AIS
separate AIS transceiver
More than one radio.

I like having switches on the side of the console, which I can reach from the bunk to turn on the night lights in the cabin, or lights outside--either to the sides or cockpit for security at night.
 
Make sure you look on EBAY for marine fuze panel.

I just bought one of those 12 slot ones new for $40 like in your picture.. from Blue Sea (good brand)

What I want it for is to isolate all my electronics connections to a single panel that I can switch on and off... when tied up yet have my radio and interior stuff on a second "house" circuit.
 
SEA3PO":3qv3wxoy said:
Make sure you look on EBAY for marine fuze panel.

I just bought one of those 12 slot ones new for $40 like in your picture.. from Blue Sea (good brand)
Click to expand...

I have an Amazon Prime membership (includes 2-day shipping at no extra charge) and they are $40.95 there, so I have one in my cart. Like you, I find the Blue Sea products to be good. They also came through with great customer service when my ACR seemed to be defective.

SEA3PO":3qv3wxoy said:
What I want it for is to isolate all my electronics connections to a single panel that I can switch on and off... when tied up yet have my radio and interior stuff on a second "house" circuit.
Click to expand...

Aha, I see. This is "gelling" my idea to just get the one 12-fuse block for now (which will cover everything I currently have plus one extra spot) and then decide on more/how many/where in future, when I know from more experience how I want to go about it.
 
As I sit here listening to the wind blow and waiting for the temperature to drop to a minus 20, I'm thinking of spring projects. One of them may possibly involve rewiring. Currently my boat has a 50 amp circuit breaker back by the battery, in the wire leading up to the fuse block behind the helm. 50 amps seems a little high. I'll have to check later what size the wire is again leading from there, but what size should it be with the 50 amp CB? Also, the wire for the anchor windless does not have a circuit breaker at the battery, but rather one located just behind/next to the helm seat. This is nice to use as a "master" switch for the windless switch, but shouldn't the CB be back at the battery with the other CB? Colby
 
colbysmith":rl27n0u9 said:
As I sit here listening to the wind blow and waiting for the temperature to drop to a minus 20, I'm thinking of spring projects. One of them may possibly involve rewiring. Currently my boat has a 50 amp circuit breaker back by the battery, in the wire leading up to the fuse block behind the helm. 50 amps seems a little high. I'll have to check later what size the wire is again leading from there, but what size should it be with the 50 amp CB? Also, the wire for the anchor windless does not have a circuit breaker at the battery, but rather one located just behind/next to the helm seat. This is nice to use as a "master" switch for the windless switch, but shouldn't the CB be back at the battery with the other CB? Colby
Click to expand...
Some where between 4 or 6 size wire. The 4 would for for electronics, (3% voltag e drop) and 6 for fans and resistive load (10% voltage drop). However, you probably will never draw 50 amps so #8 may well be "OK" and change out the breaker. Find out how much you are drawling and size the circuit breaker appropriately.

Yes, the circuit breaker should be near the battery, but C Dory has put them
up close to the helm, probably because people use the breaker as a switch. It may not be the best practice, but the breaker seems to hold up OK. As long as there is a load on them when switched, it seems to be OK.
 
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