I have soldered all of my 12 GA buss to my 20 GA feeder wires. Is it necessary to tape the connection after it is soldered? The wires are not necessarily that close to each other so I am not worried about a short but I don’t know if they can get dirty over time and this will cause a problem with the connection. If I do need to tape all of the joints, is it advisable to use liquid tape. Thanks Gary
There’s no reason to tape them off unless you have anything that can short. My buss wires don’t even have a jacket on them
Someone’s been pressing up against the wood with the soldering iron [:D]
I keep my connections offset, so there should be no issue with shorting. I do usually go back and paint each connection with liquid electrical tape though, just to be sure. Make sure you have a window open, the stuff is kind of stinky.
–Randy
I have to be a contortionist to work under the layout so I press away [:)]. Nice thing about bare copper is it’s cheap and it doesn’t have to be stripped every time I add a feeder.
I solder and tape all of my connections why, it’s just the way I was taught. With my luck I would have that one lone screw or piece of metal fall through the layout and come to rest on my unprotected buss wire.
I use that soft flexible electrical tape that used to mark wires, it comes in various colors so of course I use the corresponding colors on the buss connections to match the drops red/white That liquid electrical tape also is very handy to have around or that stuff used to coat tool handles insulating them. I use that when I need to isolate a motor when converting to dcc
A screw or any other object wouldn’t hurt anything when the bare conductors have enough separation. But if they’re jacketed like romex or any other paired wire. they should be taped or protected another way.
When you’re just putting down the trackwork, the underside of a layout looks pretty clean and orderly. But, years later when you’ve got the turnouts wired, you’ve installed signals and you’ve put lights in your structures and installed streetlamps, then the upside-down landscape gets more and more complicated.
You can only get away with un-insulated connections and bare wires for so long. Eventually, it will bite you. I burned out a power supply a couple of weeks ago when two wires below my layout touched. (That circuit is now fused for protection, but that was done in hindsight.)
When I soldered my wiring, I used Micromark’s liquid electrical tape on my connections. Came out neater than regular electrical tape, which I’ve seen come loose in the past.
Kevin
I bought the equivalent at Home Despot for a few pennies - 2?oz. can with a brush in the cover. Takes all of five seconds to dab a bare-wire solder connection - less if you are doing several at a time.
Chuck (Modeling Central Japan in September, 1964)
I agree with you on this. There’s just something about having those bus wires bare that makes me uncomfortable. If that works for someone, okay, but I don’t think it should be recommended as a general practice.
Case in point, the part of my layout that I started first. There will be THREE bus lines in the area. One for the power district that run the staging yard, one ofr the power district that runs that half of the main, and one for the power district that runs the yard and cement plant. Actually the 4th bus line for the other half of the main will ALSO run in this area since it is underneath this section I am putting my DCC shelf.
I’ll stick with ordinary insulated wire, my trusty Ideal wire strippers for no hassle middle fo the wire striping, and my trusty Weller 150 watt soldering gun to make the connection. My layout it high enough that I can sit under it on a short stool (I’m a little too tall to do it sitting on a regular chair) without having to contort my neck. And just liekw ith my previous layout, despite having feeders to every section of track, for now the two parallel 12 feet sections fo track I have work just fine with one set of feeders each. I do a little bit of everythign each time I work ont he layout - so next time, more of the feeders will get connected, and since I finished that staging yard I will be able to terminate the bus wire at the terminal strip and truly finish it off.
–Randy
I’m more than comfortable keeping the buss bare. Of course I probably wouldn’t be if I hadn’t been in electronics for 33 years. I see it as being like high voltage wires on phone poles. They run bare and not far from lower voltage wiring. It’s not a problem as long as only qualified people handle the wiring. I do agree if you’re uncomfortable with it you shouldn’t do it.
The problem is many model railroaders are novices with electrical/electronics so to publicly advocate using bare conductors may not be entirely prudent when the knowledge/skill level of the reader is unknown.
Oddly, it’s my 30+ years of experience with electrical wiring and electronics that make me want to insulate conductors all the time. In my experience the unexpected can and will happen so I like to cover all my bases by insulating conductors.
Of course, opinions vary and to each his own.
I can see how some can be concerned but if separated enough most are more than safe. I guess I picked it up replacing old knob and tube wiring in my first house. A lot of the conductors were bare from age but since they had separation a single nail or screw could never short the conductors which actually made it safer. I had left it in place for ceiling lighting at the recommendation of an old timer electrician. Many times as a technician I found shorts caused by nails or screws in paired jacketed wires. I would trust 2 single conductors spaced by 4 or more inches over a pair of 12 gauge jacketed wires any day. Take a handful of nails and try to short each one by driving them through the board above. The single wires will survive every time. Then take a drill bit and drill random holes as a modeler does with building lighting around the feeders and you’ll have similar results. The single conductors will never short but a hit to the twin conductors, not so lucky. It doesn’t sound good on the surface but if you think about it, not bad IMO.
Interesting. I have never seen Knob and tube wiring that I myself would consider SAFER than ROMEX NMD-90 but I have removed plenty of knob and tube that showed signs of being a potential fire hazard. If electrical wiring is installed correctly the incidents of a standard length drywall screw shorting a cable are not all that common. Now if a homeowner hangs pictures with 3 inch deck screws anything can happen!
In any event on the layout I wouldn’t use a cable with two or more conductors in a jacket. That just seems inconvenient for stripping and soldering. I would use single conductor insulated wire and space them adequately for easy access and convenience. I’m with Randy and his Ideal wire strippers.
I’m not saying what you do is wrong, for you, just not ideal for the masses perhaps.
FWIW: This evening I had to track down a short on the railroad. I have been doing hardshell work for the last six months and when I fired it up tonight, dead short. Took twenty minutes to find the crossed bare wire feeders. Ironically they were insurance feeders I put in before the hardshell buried the track., They weren’t hooked up to the buss and were hanging there, crossed.
In general I dont cover or insulate connections unless they are leading up to the switch panels where movement of accessing the panels might cause contact. I do use insulated (but not romex) buss wires and stagger the feeder connections ala Randy and others. I am also careful to use point to point wiring with no splices to cut down on extraneous places to short. With 500 feet of track, 70+ switch machines and tons of other electrical, I would still be taping if I insulated every connection.
Guy
The vast majority of my electrical connections are uninsulated - but they fall into two distinct categories:
-
Wires soldered to solder lugs on various components.
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Wires secured to stud-and-nut terminals on terminal blocks, several per stud with washers between.
All of the wire connecting the usual 1 - 2 - 2 - 1 circuit are insulated full-length and unspliced.
Chuck (Modeling Central Japan in September, 1964)
I used the liquid insulation stuff painting on each connection after checking out the circuits and testing. Doesn’t take very long to go down the buss and paint each soldered joint. Just makes sense to me to not leave bare.
Hal
I guess one way to look at it is the buss wire is uninsulated and only a little more than a half inch apart. (It’s called the track). It’s even closer at turnouts. So an uninsulated buss that has 4 inches of separation is almost 7-8 times the separation.
I agree wholeheartedly. I wouldn’t be so worried about something touching the two bare wires and creating a short, but rather an overload/short (or even a lightning strike-have you got a surge protector?) somewhere else in the line and the close proximity of the bare wire to the wood benchwork, the wire could overheat and ignite the wood, which has most often been the cause of house fires with the old knob and tube wiring.
This may not be much of an issue with a DC layout, except with the aforementioned lightning strike*, but with DCC it’s another story; DCC has a potential of 2-5 amps or more going thru those wires, any overload/short could be a danger with the bare wire. 5 amps can easily create enough heat to weld, let alone burn wood. One thing Knob and Tube had, was standoffs to prevent direct contact with wood. I do think what you are doing is wrong from a safety point of view and would never recommend it.
If and when I have to use tape to insulate a join, I also use a cable tie so the tape won’t unravle over time.
&n