I have three-conductor tinned 22 AWG stranded wire that I'd like to use on my railroad. Reading online, tinned wire is not recommended with screw terminals because tinned wire compresses or shrinks under the screw and becomes loose, increasing resistance. Is this a concern on a model RR, enough to say buy new wire?
not a problem ..
Are we talking a wire end dipped in solder or a solder colored wire that is plated. There are no issues with plated wire. It is actually better because it resists oxidation. If the end is dipped you can cut it off if you don't like it. The big concern with the types of wire and connections is when you need UL or some other agency approval.
Lee
"Can tinned wire be used with distribution blocks or screw terminals?".
IDRickReading online, tinned wire is not recommended with screw terminals because tinned wire compresses or shrinks under the screw and becomes loose, increasing resistance.
"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."
Hello All,
I tin the wires on my screw terminals and when using crip on connectors and have had no problems.
When I tin the wires for screw terminals I bend the tinned end into a "J" shape and feed the wire from the left side, so as the screw is tightened; clockwise, it "pulls" the wire into the terminal.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
Lee 1234 Are we talking a wire end dipped in solder or a solder colored wire that is plated. There are no issues with plated wire. It is actually better because it resists oxidation. If the end is dipped you can cut it off if you don't like it. The big concern with the types of wire and connections is when you need UL or some other agency approval.
My wire is labeled as being tinned by the manufacturer and looks like aluminum wire when stripped. Sellers frequently describe it as reducing oxidation. Sounds like it is the plated type and should be good to go! Thanks!
Thanks JaBear and jjdamit for your answers and added information! Most appreciated!
The 'revealed wisdom' when I was learning soldering technique was that tinning stranded wire was done with adequate flux of the correct type, with correct heating of the 'joint' between the strands for full wetting and bond, and using a solder alloy that was not brittle under compressive stress (in other words, comparatively soft).
The conductivity of solder is lower than bare copper. But untreated, copper under a screw terminal may oxidize to an ultimate lower conductivity than a tinned conductor...
I don't think I have ever used push terminals with untinned wire when I had the option of tinning. I found tinning stranded wire correctly relieves the tendency to 'crush' the strands out of the contact region between the screw head and base, especially as the screw is tightened with no 'restoring tension' to keep the looped wire tight against the screw 'all the way around'.
Of course for serious 'screw' terminals the screw is at right angles to the axis of the wire, and compresses the conductors without stretching or spreading them.
I would be concerned with how much current the 22 AWG wire would be carrying. A few hundred mA, no problem. As far as attaching the wire to a screw, a closed terminal lug crimped with a calibrated crimp tool would be best. A tinned wire the least.
Former Car MaintainerI would be concerned with how much current the 22 AWG wire would be carrying. A few hundred mA, no problem. As far as attaching the wire to a screw, a closed terminal lug crimped with a calibrated crimp tool would be best. A tinned wire the least.
The general conclusion is that the voltage drop over any length that 22ga wire would be used is not particularly significant. You wouldn't use it for feeders, but no one would.
The major issue with tinning is actually that it contributes to stress raising at the point where the tinning goes to bare copper, which may lead to cracking or breaking at that point. Correct tinning would tend to anneal the copper a fair distance from this zone, in my opinion reducing the potential issue; equally obviously, providing bending strain relief across the transition limits the concern.
I'd concur that a good spade or ring terminal attached to the wire end would be better than any clamping bare wire under a screw head. But I would also be concerned with a crimp connector that poses a sharp transition from the effective 'crimped zone' to what may be unannealed drawn wire. This might be significant at the smaller solid as well as stranded wire sizes. (And tinning outboard from the crimp would give stiffer bending resistance at the crimp, distributing the bending load better...)
Overmod We've had a number of threads over the years discussing these. The general conclusion is that the voltage drop over any length that 22ga wire would be used is not particularly significant. You wouldn't use it for feeders, but no one would. I'd concur that a good spade or ring terminal attached to the wire end would be better than any clamping bare wire under a screw head. But I would also be concerned with a crimp connector that poses a sharp transition from the effective 'crimped zone' to what may be unannealed drawn wire. This might be significant at the smaller solid as well as stranded wire sizes. (And tinning outboard from the crimp would give stiffer bending resistance at the crimp, distributing the bending load better...)
We've had a number of threads over the years discussing these.
Anti wicking tools are employed to prevent tinning traveling too far up the wire.
Any wire suffering an annealing problem with the use of crimp lugs should be upgraded to a more suitable wire.
The original poster referred to distribution blocks which imply "feeds".
Routing Consideration of 22 AWG bundles should take into consideration cross interference, ground loops and voltage drops for small signals such as DCC or block level controls.
IDRickCan tinned wire be used with distribution blocks or screw terminals?
The OP did not seek guidance regarding the application- -but the viability of using "pre-tinned" wire.
Former Car MaintainerRouting Consideration of 22 AWG bundles should take into consideration cross interference, ground loops and voltage drops for small signals such as DCC or block level controls.
Great point!
Our responses should focus on the OP's initial question and our not presumption of usage- -which is another subject (thread).
If the OP is seeking guidance on the application, I am confident in their ability to post that topic.
jjdamnit The OP did not seek guidance regarding the application- -but the viability of using "pre-tinned" wire. Our responses should focus on the OP's initial question and our not presumption of usage- -which is another subject (thread). If the OP is seeking guidance on the application, I am confident in their ability to post that topic. Hope this helps.
Exactly. Without knowing the specific application, a precise answer can't be deduced.
Former Car MaintainerExactly. Without knowing the specific application, a precise answer can't be deduced.
Thank you... !!!
Oops, sorry for not explaining my application. I'm setting up a 2 ft x 8 ft switching layout with atlas undertable switch machines and mini SPDT toggles (temporary on off on). Max of 8 turnouts (no more than 2 operating at one time) and using a Circuitron Snapper CDU. I have them on hand, figured I would use them. BTW, I switched out the three conductor 22 AWG stranded, tinned wire with four conductor 22 AWG, stranded, tinned wire. I could take it back if it is an error. Gives me four unique colors, most helpful for careful wiring of the atlas switch machines + SPDT toggles.
Wiring plan
1) 18 AWG from AC terminal of power pack to the CDU
2) 18 AWG from CDU to distribution block
3) 22 AWG drops from the distribution block to the SPDT toggles and switch machines
4) solder connections to CDU
5) screw terminal connection at the distribution block
6) solder connections to the toggle switch
7) screw terminal connections at the atlas switch machine
8) Use 18 AWG solid copper wire to solder to rails for feeders.
IMO, this should work, don't believe I am breaking any rules according to Atlas...
The comment on interference is concerning to me. I have not heard of there being interference issues with Atlas products and SPDT toggles.
Thoughts?
Overmod,
I am planning to use these connectors for the 18 AWG feeder drops to 18 AWG power buss (only one locomotive on layout on 8 ft long layout) Probably should use 14 AWG power buss in considering DCC
https://www.amazon.com/Connectors-Wiring-Conductor-Terminal-Assortment/dp/B09TPPVMK5/ref=sr_1_68?keywords=Wago+Wire+Connector&qid=1660783370&sr=8-68
Kinda pricey but, IMO, a good way to organize wires to the power buss. I like the wago connectors and like to use them.
What are your thoughts?
Good day JaBear! We're on the same page.
I will use a similar terminal strip for setting up the turnout power buss.
For example, see https://www.amazon.com/FIXITOK-Terminal-Positions-Pre-Insulated-Barrier/dp/B08D3H52KV/ref=sr_1_1?crid=3SGZZFCMYH8EC&keywords=Terminal+Strips%2C+FIXITOK+6+Sets+4%2F5%2F6+Positions&qid=1660838674&s=industrial&sprefix=terminal+strips%2C+fixitok+6+sets+4%2F5%2F6+positions%2Cindustrial%2C142&sr=1-1
The wago connectors (mentioned in my previous post) are $1.39 each to connect both rails of three tracks to the power buss. Tidy and easy to make connections. Reduces the amount of wiring under the layout.
And speaking of terminal strips...
Using terminal strips for DCC wiring
It's an oldie but a goodie.
jjdamnit Hello All, And speaking of terminal strips... Using terminal strips for DCC wiring It's an oldie but a goodie. Hope this helps.