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Blue Sea Question


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Maybe this is a simple question...

 

I currently have a the power to the box fused, but I'm not sure if I can source a larger fuse than a 30A. This may be a problem as I have wired all lights redundantly. I'm betting that when the HID's fire up, it'll pop the 30A fuse.

 

The block is rated at 60A. Opinions?

 

Other than that, it's turning out to be a clean install!

 

Thanks for any input,

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ShovelStrokeEd

Allen,

40 amp fuses are available.

 

You might not pop that fuse when the HID's fire up. The word fuse derives from fusible and that's what happens when the fuse goes, it melts. Well, the melt comes from heat which comes from time and current. If the time for the inrush current on the HID's is short enough, no need to worry about fuse.

 

In point of fact, fuses are there to protect the wiring from damage due to excess current. If the fuse is properly sized and the wiring is as well, you should have no problems.

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Without knowing all the loads you're going to run, hard to say what you need in the way of fusing and whether 30 or 40 amp protection will be adequate.

 

This might be helpful in calculating proper fuse size

 

Good luck

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Allen, I run my MotoLights (70w), my Hella's (110w), my Gerbings power supply (I forget how many watts) plus radar detector and autocom (10w tops) through a 15-amp fuse. Hasn't popped yet. If it ever does, I'll bump it to a 20-amp.

 

You should be more than adaquate with 30-amps. I'd start around 15 and work my way up as they pop. No sense in over fusing a circuit.

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I have not fused the hot lead 'TO' the fuse block on any of my installations, but I'm extremeley carefull about hot lead routing and protection.

 

Fusing the lead to the fuse block is not actually required, but is certainly a good idea. You can get fuse holders for fuses rated up to hundreds of amps, but they won't exactly match the fuses in your BMW or Blue Sea fuse blocks.

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Thanks guys! Good replies. I haven't computed the amperage yet, but I'll have two sets of lights at 110w each, 220w total, plus the HID's 70w total maybe? Plus the tank bag power which is really negligable...

 

Call it 350/14.4 and I get ~24A. Should I use the charging voltage of 14.4 or just use 12v? Either way, it looks like I'll be fine.

 

I was mostly uncomfortable in NOT using a fuse to the panel. If the hot lead shorts to the frame, it won't be pretty. Unless you light flaming BMW. That might look cool actually. Just not on my bike.

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Without knowing all the loads you're going to run, hard to say what you need in the way of fusing and whether 30 or 40 amp protection will be adequate.

 

This might be helpful in calculating proper fuse size

 

Good luck

 

THAT is a cool link. All this time I've been guessing...and guessing wrong! But close...

 

Thanks!

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Allen:

 

I installed the 12 fuse BlueSea unit on my K1200LT. All my accessories run of the fuse block except for the powered Hide-Away FM stealth antenna. That is run through an ignition switched source. I used a circuit breaker between the BlueSea and the Battery positive. I used the 75 AMP one. My total on the fuse block is 64 AMPs. But not all items will be on at the same time. There is no relay between the BlueSea and the battery.

 

Raffy

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Thanks Raffy! Good to see you trolling around over here. I've seen some pics of your set-up over on the K12 site.

 

Question; What type of fuse did you run between the battery and the blue sea? It's out of curriosity really as I don't think I'll exceed the 30a I've currently installed.

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I used a circuit breaker between the BlueSea and the Battery positive. I used the 75 AMP one. My total on the fuse block is 64 AMPs.

 

Zowwie, wowwie, Raffy. What are you running that requires a 75 amp circuit breaker? That's like 1,000 watts. eek.gif

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ShovelStrokeEd

Not only is it 1000 watts, if the wire between the battery and the Blue Sea is anything smaller than 8 gauge or so, in the event of a short circuit, the wire will heat up and maybe start a fire before that breaker trips. Remember folks, the fuses are not there to protect the loads, they are there to protect the wires.

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I used to have a link for Sesquhana <sp> motorsports, a company that sells lights and equipment for rally cars. On their website, they used to have a very handy tool for determining loads and selecting proper wire gauges.

 

As a note, a common mispercecption is it's OK to use larger gauge wires, when it fact, it can cause voltage drops. On the other and more dangerous hand (left hand for me) too small of a gauge and your wires melt. Especially if the calculation for the the fuses is wrong!!

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I used to have a link for Sesquhana <sp> motorsports, a company that sells lights and equipment for rally cars. On their website, they used to have a very handy tool for determining loads and selecting proper wire gauges.

Someone mentioned them somewhere before- rallylights.com.

 

They've got some decent deals on lights and have a selection of relays, light harnesses with relays, fuse blocks, etc. in addition to all the wiring information.

 

I'm thinking of getting the Optilux 1100 or 1450 for compiscuity lighting.

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Quote:

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...As a note, a common mispercecption is it's OK to use larger gauge wires, when it fact, it can cause voltage drops...

 

--------------------------------------------------------------------------------

 

Uhh, would you please expound on that?

Yeah Allen's totally lost me on that one too. That's not the way I leaned it in electrical engineering school. 'course that was 30 years ago. Maybe electricity in wires works different now. wink.gif

 

OK Allen, this ball's in your court. Care to explain how bigger wires are worse?

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Quote:

--------------------------------------------------------------------------------

...As a note, a common mispercecption is it's OK to use larger gauge wires, when it fact, it can cause voltage drops...

 

--------------------------------------------------------------------------------

 

Uhh, would you please expound on that?

Yeah Allen's totally lost me on that one too. That's not the way I leaned it in electrical engineering school. 'course that was 30 years ago. Maybe electricity in wires works different now. wink.gif

 

OK Allen, this ball's in your court. Care to explain how bigger wires are worse?

 

Nope, I can't explain it. I'm wrong. I was taught, ableit not in engineering school confused.gif that at a point, a larger wire would cause a voltage drop. It seems (seemed) to make sense to me. However, and you as guys know, this is not the case:

 

http://www.powerstream.com/Wire_Size.htm

 

Here is a really cool link that allows one to choose wire size, current and length of wire and gauge of wire to determine voltage drops. My premise is simply not true! I've learned still more here!

 

Of course I DID post it on the internet, therefore it must be true! blush.gif

 

Thanks for the challenge and giving me the chance to research! This is fun stuff. thumbsup.gif

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Nice mea culpa, Allen. thumbsup.gif

 

It's really hard to slide things past these guys. There is always someone around who has a substancial experience with the relevent topic. It helps keep things accurate and on the up-and-up. cool.gif

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Nice mea culpa, Allen. thumbsup.gif

 

It's really hard to slide things past these guys. There is always someone around who has a substancial experience with the relevent topic. It helps keep things accurate and on the up-and-up. cool.gif

 

Damn, it IS hard to slide things past confused.gif The great thing is though that there a great folks that can help set the rest of us straight when in comes to mis information. There is plenty out there as well! Of course then idiots like me spread bad info, so the tech police have to step in grin.gif

 

But really, this shows how helpful and knowledable this board is. I love it! thumbsup.gif

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I'll try to help you save face.....Maybe you were thinking wire gauge "designation", as gauge designation increases in value as wire gauge decreases in size/cross section. ie: #10 is physically smaller than #8....smaller wire=more resitance=higher voltage drop.

This is only true till you get larger than # 1 and get into "ought" sizes...gauge designation increases w. cross section however, it would be a bit of overkill to use something like 2/0 on the bike :-)

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Damn, it IS hard to slide things past The great thing is though that there a great folks that can help set the rest of us straight when in comes to mis information. There is plenty out there as well! Of course then idiots like me spread bad info, so the tech police have to step in

 

I've seen it work really well here when folks don't get stubborn and don't have their ego invested in the point they're trying to make. When the opposite is true, the threads stretch to many, many pages and become quite comical. Fortunately, with technical things, we can usually find some objective info to set us straight. I guess that's why I like tech stuff. grin.gif

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Maybe you were thinking wire gauge "designation", as gauge designation increases in value as wire gauge decreases in size/cross section. ie: #10 is physically smaller than #8
Good point. Never could understand why that is anyway. It's probably in the old memory banks somewhere, but then I've forgotten more than I ever knew.
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I'll try to help you save face.....Maybe you were thinking wire gauge "designation", as gauge designation increases in value as wire gauge decreases in size/cross section. ie: #10 is physically smaller than #8....smaller wire=more resitance=higher voltage drop.

This is only true till you get larger than # 1 and get into "ought" sizes...gauge designation increases w. cross section however, it would be a bit of overkill to use something like 2/0 on the bike :-)

 

That could have been it...at least while I know that smaller numbers mean larger wires, I could have inversed those while I was learning without inversing that in my memory banks leading me to believe that larger wire would cause a drop.

 

Hey, I'm wrong a lot. It's no big wow. grin.gif

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I think "gauge" designations originate in the number of units it takes to make a certain length.

 

So maybe eight 8awg wires side by side makes an inch or something like that. Then 24 - 24awg wires make an inch. Hence, it takes more of something smaller to make the same distance. Thus the number goes up as the actual size goes down.

 

I don't think those are the actual numbers, but that's the general idea.

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That could have been it...at least while I know that smaller numbers mean larger wires, I could have inversed those while I was learning without inversing that in my memory banks leading me to believe that larger wire would cause a drop.

 

Hey, I'm wrong a lot. It's no big wow. grin.gif

 

 

I think you're supposed to say (doing your best John Lovitz imitation) "yeah, I meant gauge designations....that's the ticket" :-)

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Ed,

 

Nice table! I was looking for one like that when starting the project!

 

One thing to note, and if anyone is in the middle of a project, have a look at this; You can generally and safely use as much smaller guage (higher #!) wire than you probably thought. I listed another table in this post which will allow you to measure voltage drop which is particularly important for light upgrades.

 

I'll post pictures of the completed project, but...I've got a bunch of light...might have a little overkill...I don't know yet. thumbsup.gifthumbsup.gifthumbsup.gif

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