Author Topic: Wiring question  (Read 2794 times)

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cec209

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Wiring question
« on: August 25, 2009, 03:46:06 PM »
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I'm getting ready to wire/rewire several NTrak modules to the latest NTrak RP (12 AWG bus and 22 AWG feeders.)  Though these modules will normally be part of my home layout using DCC, I want them to be wired so they can be included in a larger show layout with DCC

I'd like to minimize the soldering and use suitcase (Scotchlok) connectors to connect the feeders to the bus. My problem is finding a suitcase connector that can handle the 12 AWG bus and the 22 AWG feeders. I've tried doubling over the 22 AWG feeders but without getting a connection.

The DCC corner in the Sept MR has an article touching on the subject and using Scotchlok connectors but no mention of which size.

I thus submit my dilemma to you, the experts. Please forgive the cross posting.
Charlie

Philip H

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Re: Wiring question
« Reply #1 on: August 25, 2009, 04:13:08 PM »
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The problem is I have yet to see a 12-22 scotch-lok or other suitcase connector.What I find are a lot of 12-18 and 16-22's.  If you do get a sources, let us know.
Philip H.
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bicknell

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Re: Wiring question
« Reply #2 on: August 25, 2009, 04:31:21 PM »
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Never seen such a thing, unfortunately.

I find it really easy to remove a short segment from the 12ga wire with an xacto, just go all the way around about a half inch apart, then cut a line between the two with the tip.  That segment of insulation should pop right out.   Wrap the feeders around it and solder them all at once.

See http://realityreduced.blip.tv/file/947002/ for a video of how I do mine.

qantaqa

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Re: Wiring question
« Reply #3 on: August 25, 2009, 05:32:03 PM »
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This seems like a pretty common issue...

Hit up your local NAPA and look for "T-tap Female Connectors" in yellow (10-12ga) p/n 784388 for the 4 pack.  These are really similar to our revered suitcase connectors, except that the "2nd wire" is a 1/4" male blade disconnect (NAPA p/n 784390, 18-22ga 20pack)... also larger quantities available... I can post (or send) pics of the packaging, too...

Prolly possible to locate these type of products at other stores... NAPA is where all the local RR'ers buy them (small island, I guess) -- also they offer an AAA discount (and if enough of us ask, maybe an NMRA discount, like we convinced our local home supply to do, too)

Cheers from Fidalgo Is.

John

mmyers

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Re: Wiring question
« Reply #4 on: August 25, 2009, 08:11:55 PM »
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I'm with Leo favoring soldering. That's why there is only a brief reference to 3M #567 suitcase connectors in the RP or the FAQ.
I gave a clinic on it at Louisville last year. Instead of wrapping the feeder around the bus cable, separate the strands into two halves with a hole in the center. Bring the end around both halves and thread the end back up through the hole so that it's paralel to the rest of the feeder wire. Now solder the whole works. Even if you get a cold joint, the wire still has a mechanical connection to the bus.  Offset the feeder connections so they don't short out. I had a wire strand poke through several layers of tape and short on the other bus wire. Connections were side by side on the bus wires. Took a while to find that one because it was intermittent. Some lessons are learned the hard way. :(

The T-Taps mentioned are also an option if you use wire for the bus that will fit in the IDC. Low voltage lighting cable won't fit, I Tried that already.
Another option would be to use a 567IDC and 18 ga wire for the bus tap. Run the 18 ga to a terminal strip and connect your 22ga at the terminal strip.

Martin Myers

Dave Schneider

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Re: Wiring question
« Reply #5 on: August 25, 2009, 08:30:43 PM »
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I haven't gotten to the stages where I am ready to wire up modules, but I am hoping to do so soon.  It looks like 14-22 AWG connectors are readily available. How long of a run can be made with a 14 AWG bus?

Best wishes, Dave
If you lend someone $20, and never see that person again, it was probably worth it.

mmyers

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Re: Wiring question
« Reply #6 on: August 25, 2009, 08:33:48 PM »
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The RP is 12 gauge. Standard is 18 gauge. Both are acceptable. Haven't tested 14 ga for voltage drop. We did tests for 12ga and found that lengths up to 100 feet one way would work. For practical reasons we dropped that to 80 feet maximum one way. there is real improvement in both DCC and DC operation with less adjustment needed to DC throttles to maintain speed over the lengthn of a block. We've also found that Dc blocks can be more reliably powered from the ends. That allows throttles for adjacent blocks to be grouped together. Less operators needed.

Martin Myers

Dave Schneider

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Re: Wiring question
« Reply #7 on: August 25, 2009, 08:38:11 PM »
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Thanks for the quick reply and information Martin! I appreciate it.

Best wishes, Dave
If you lend someone $20, and never see that person again, it was probably worth it.

Hiroe

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Re: Wiring question
« Reply #8 on: August 25, 2009, 10:46:57 PM »
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why not just strip about 1.5" from the 22-ga wire, fold it over twice (so it's 1/2" long total, but tripled), and solder the triple segment into a solid before inserting it into your scotchlok connectors? That should give it the meat necessary to make a good connection.
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Walkercolt

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Re: Wiring question
« Reply #9 on: August 25, 2009, 11:30:20 PM »
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The USAF taught me to strip and tin the "buss wire" then tin the "feeder"(I prefer solid conductor) then "spiral wrap" the feeder several turns and solder it then use MIL SPEC electrical tape. However, I believe "Joe Average" would be better off using 40-60 AMP Euro Terminal strips with tinned wires. Less chance of "cold" solder joints to me. (I have fixed too many on my back under a module the night before the show opens and dropped hot solder on arms, hands, ears, and face.) "Suitcase" connectors cut alot of conductors, so I'm not a fan of them for high-current use. BTW: 14 ga. vs: 12 ga. will cut your current and more importantly the DCC signal 25-30% over 80 feet (N-TRAK RP).

oakcreekco

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Re: Wiring question
« Reply #10 on: August 25, 2009, 11:41:07 PM »
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On my layouts I use "DIN Rail" connectors. You can buy them at Automation Direct.
A "western modeler" that also runs NS.

mmyers

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Re: Wiring question
« Reply #11 on: August 26, 2009, 04:35:10 AM »
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I don't think that Euro terminal strips can be used. The RP calls for an unbroken bus to reduce resistance. Wrapping and soldering is the best connection because as noted, IDC's can damage conductor which also increases resistance.

bicknell

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Re: Wiring question
« Reply #12 on: August 26, 2009, 10:12:23 AM »
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Terminal strips do not hold up well to vibration.  If the layout were static then I would be all for terminal strips, but the reality is when you haul modules around in the back of a pickup or trailer the vibration makes the connections go loose or even fall out.  That's why the new RP doesn't allow them.

The T connectors aren't bad, good solid connection and a nice blade connector which should stand up to vibration.  Still, I think soldering is the way to go to be 100% sure.  Nothing can turn people off of railroading faster than a 3 hour electrical troubleshooting session while the public keeps asking if a train is going to run soon.  The electrical not only needs to be up to scratch, it needs to be over-engineered, over-installed, and over-labeled.

ChrisNH

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Re: Wiring question
« Reply #13 on: August 26, 2009, 12:36:06 PM »
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I am a big fan of the European style connectors. They are reliable and do not require the wire to be bent around a screw.  They can be trimmed to length and each conductor is completely isolated. I use this style of terminal strip for all my connections where a terminal would be appropriate. Otherwise, also being an air force guy, I open, wrap, and solder. I may re-examine this since while I share the same misgivings about suitcase connectors they seem to be working reliably for a lot of people.

Anyway, I think groups which do not allow terminal strips need to re-examine this in light of the newer ones available.

Chris

Hiroe

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Re: Wiring question
« Reply #14 on: August 26, 2009, 04:44:06 PM »
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I'm also a fan of the Euroblock style terminal strips. With the compression-type connection, i don't see them being too much of a problem for signal loss. I've used dozens of them over at Cherry Valley on the 10-ga busses for the mainlines with no issues; and i even used them at each end of a 3000' 10-base-T network cable, which i'm actually using right this very instant to be online typing this post. Works great!

--Drew
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