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Fuse Rating on track Feeders

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Fuse Rating on track Feeders
Posted by Anonymous on Sunday, February 17, 2008 12:32 PM

Call Me Redundant, but Safe....

I want to use fuses in my track power feeders, 1 fuse per block, I might have 2 engines running short trains in 1 block at a time (powered A, powered B) Will a 2 or 3 amp fast blow fuse be ok?

Or what should I use, I have mostly deisel Athern, Walthers, Tyco (yeah I Know), Life Like

Im not running DCC for a few years yet. 12' X 16' layout

 Thanks again for all your help.....

 sowwy, I id a wedneck hillbiwwy  lolol 

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  • From: Winnipeg Canada
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Posted by Blind Bruce on Sunday, February 17, 2008 12:49 PM

I agree with you. The fuses ARE redundant. Your power pack fuses will be good enough and when one of them blows, you will know where to look. Individual fuses at feeder locations will need to be located at the feeder location OR have long wire leads to a master panel. Lots of extra work in my opinion.

So, to answer your question, figure 3/4 A per loco and use 1 1/2 A fast blow fuses. If you run the fuse wires back to a panel, use #18 or larger so the voltage drop will be small.

73

Bruce in the Peg

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Posted by SteelMonsters on Sunday, February 17, 2008 1:25 PM
 TerminalCardiac wrote:

Call Me Redundant, but Safe....

I want to use fuses in my track power feeders, 1 fuse per block, I might have 2 engines running short trains in 1 block at a time (powered A, powered B) Will a 2 or 3 amp fast blow fuse be ok?

It is redundant. I don't have a problem with that. The problem is that it is not functional. Every short will cause a fuse to blow out. The layout will not run until you correct the short then replace the fuse. If there is still a short on the line and you replace the fuse, you will be replacing it again. Fuses seem cheap until you realize that shorts happen often. The layout won't be any safer, it will just be less enjoyable to run.

Auto-reset electronic circuit breakers are great. If there is a short, then shut off and every few seconds send a test current then shut back off until the short is clear. At that point, they come back on automatically. DCC boosters have them internally and there are external breakers for making power districts. Power districts allow larger layouts to be split up so a short in one district won't effect other districts. DC power packs usually have something simular. Fuses just don't work for track power. 

On the other hand, I strongly recommend fuses for any accessory power that you have. You don't have the protection from the power supply. Also, it's more difficult to find shorts in the wiring if they occur. Fuses will help you locate shorts and significantly reduce the chance of anything happening. Light bulbs draw 7-10 times as much current on startup so either get a larger fuse or a slow blow fuse for the current drawn. Once a fuse is correctly sized for this application, they shouldn't blow unless there is a problem.

-Marc
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Posted by tomikawaTT on Sunday, February 17, 2008 1:58 PM

Rather than use fuses, use automotive bulbs.  Pick one that uses approximately 2 amps, and wire the sockets in series with your track blocks.  If the current reaches the point that the light comes on, you know you have a problem.

The nice things about using bulbs:

  • They give a visual indication of where the trouble is.
  • They can be installed in your track diagram - no trying to remember which bulb is connected to which section of rail.
  • They reset themselves - no cost, no fuss, no action required.

Not exactly a new idea.  I picked it up from a 1974 article in MR

Chuck (modeling Central Japan in September, 1964)

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Posted by Anonymous on Sunday, February 17, 2008 2:28 PM

 Once again I am amazed at the vast amount of experience on this forum!!!

AND THE SPEED!!!   WOW!!

Advice well taken gentlemen!!Approve [^]

I find myself humbled, and as usual,... swallowing my pride!...whew Bow [bow]

besides sounds like less work for me!!  lolBig Smile [:D]

fuses? did I ask a question about fuses?...  not me!! lol Dunce [D)]

Thank you!  Thank You! Thank You! 

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Posted by larak on Monday, February 18, 2008 10:57 PM
 tomikawaTT wrote:

Rather than use fuses, use automotive bulbs.  Pick one that uses approximately 2 amps, and wire the sockets in series with your track blocks.  If the current reaches the point that the light comes on, you know you have a problem.

Chuck (modeling Central Japan in September, 1964)

 #1156 Bulb 

The mind is like a parachute. It works better when it's open.  www.stremy.net

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Posted by selector on Tuesday, February 19, 2008 12:53 PM

I have four such bulbs wired into four sub-buses on my layout.  They work superbly, cheaply, reliably.  Light goes on, I look to that part of the layout, quickly see what needs attention, fix the problem, light turns off on its own.  Cost per district...maybe $1.50?  I don't get the base station cutting out with the bulbs, and none of the decoders gets the damaging short current that might cause the magic smoke to come wafting out of the enclosure.

(We need a smilie for magic smoke)

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Posted by Anonymous on Wednesday, February 20, 2008 1:21 PM

so does this bulb (an old brake light bulb, right,.. or were these the reverse gear bulbs?) apply in the circuit in place of a fuse? ; Spliced into either the hot or the ground wire, and does it matter which one? Question [?]

 

 

myself and the magic smoke have been WELL acquainted for decades!!!  lolSign - Dots [#dots]

 

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Posted by selector on Wednesday, February 20, 2008 2:36 PM
Yes, the older tail light bulb, #1156 I think it is, and they are wired in series to one of the feeders.  I cut the + feeder, soldered the one end to the bottom "button" and the other end to the side of the metal cup holding the bulb.  That's all there is to it.
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Posted by Anonymous on Wednesday, February 20, 2008 5:15 PM

Functional, Inexpensive,.. and light under my table!......kinda like a "Lighted magic SMOKELESS ASHTRAY for HO"!!!!!  SPLENDID!!!!!!  lolBow [bow]  I will be using this!!

even though im gonna use CAT5 and 20guage and 14guage, I still have brain farts, cause im a "lil" older now, and with the huge bowl of spaghetti Ill be trapped in,.. I need all the help i can git!   Sigh [sigh]

Thank You!! 

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Posted by larak on Wednesday, February 20, 2008 7:49 PM
 TerminalCardiac wrote:

so does this bulb (an old brake light bulb, right,.. or were these the reverse gear bulbs?) apply in the circuit in place of a fuse? ; Spliced into either the hot or the ground wire, and does it matter which one? Question [?]

myself and the magic smoke have been WELL acquainted for decades!!!  lolSign - Dots [#dots]

 

Either feeder as long as you double gap. If you use common ground wiring then the bulb goes in the hot lead.

The bulb is used instead of the fuse but does not serve exactly the same purpose. A fuse limits current (to zero and forever). An incandescant bulb limits current to some maximum value (2 amps for the 1156), and self resets after the short is removed. Also it has almost zero resistance below the two amp rating, with resistance rising rapidly and non-linearly as the limit is reached. It's really an excellent device. It also lights up so you can see the area where the short occured. Now that's high tech! Wow!! [wow]

The mind is like a parachute. It works better when it's open.  www.stremy.net

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