I have a 4 x 8 DCC layout composed of EZ track. I am getting ready to get rid of the terminal re-railers and solder feeders from each piece (or maybe every 3rd or fourth piece) of track.
my question is as follows:
can i use 22 gauge for the feeders and 16 gauge for the bus? feeders will only be 9 inches long max each and bus wire will be approximately 30 feet long along the track in total.
the 12 gauge from the NMRA standard for the bus , or it might have even been 10, seems over kill IMO
thanks
The bigger the better.Too small of feeders under heavy load will causes resistance issues.Just like plumbing if you use a 1/2 inch pipe for flow when a 3/4 or 1 inch is required to supply a good source you will have higher pressure ,but lower volume. This restriction will cause a drop in volume on demand of max volume.In electrical terms brown out,or burnt melted wire when they are too small.Just seems the simplest way to describe how it works being you cannot see the electricity until it jumps out and bites you.
Johnny
On a 4x8 I use 12ga solid wire for the bus and 20ga stranded wire for feeders. 22ga might work okay, but I find it gets warm under a heavy load. YMMV.
Len
Thanks , well I definitely don't want any problems so I will use 12 and 20. I just find it hard to believe that an amp or two could cause wire to heat up but I will take the advice that is why I asked ... The dollar amount between those recommended and what I wanted to use is very small.
I have successfully used 18 guage dual conductor wire on layouts far larger than 4x8, even with dcc the
re wasn't a problem. on a 4x8, you shouldn't have any feeder over about 6 feet long if your command station is properly located.
Well ... I don't really have a good quality command station ... I have dynamis ... So I didn't want to gang the feeders together and then connect them to the unit because it has a small electrical connection in the back so I decided to go with buss wires. Therefore each feed from the track to bus will only be about 9 inches. The buss wire will be about 50 feet total to cover the perimeter of the layout and then I'm gonna have the station further away so it is out of the way and so that the receiver is placed in better sight
Dynamis has good quality in power to where a booster is not needed unless your going over a scale mile and a half 2 track with sidings. I can run 3-4 large trains with sound. Only problem I have had is communication with the base .A few mirrors in the layout room fixed that.Bounces the signal.
Johnny
I haven't had any problems with reception but I do get major interference with my tv and or my ceiling light ... The light had to be off or it will NOT work
So you have a night time railroad.
QuoteI have a 4 x 8 DCC layout composed of EZ track. I am getting ready to get rid of the terminal re-railers and solder feeders from each piece (or maybe every 3rd or fourth piece) of track.
Quotecan i use 22 gauge for the feeders and 16 gauge for the bus? feeders will only be 9 inches long max each and bus wire will be approximately 30 feet long along the track in total.
QuoteThe buss wire will be about 50 feet total to cover the perimeter of the layout
How many lokies you running at a time? How many with sound? More than 2?
There is absolutely no reason to have a 50' buss for a 4x8 layout. You are adding unnecessary cost, without adding benefit. And you're fighting yourself dealing with wire length resistance. ??
Not sure I understand the logic in that.
A six/seven foot strip right down the middle would suffice (long end to long end and centered). You could spider your feeders from this or tidy it up with a terminal block(s).
In this case, 12 buss and 20 feeders is way overkill, fine enough, running one or two sound lokies.
I too, like plenty of reserve when wiring. And yes, error toward bigger size. That is always good advice.
Just I have to do a CBA to justify.
QuoteWell ... I don't really have a good quality command station ... I have dynamis ... So I didn't want to gang the feeders together and then connect them to the unit
I want to put my command station away from the layout on the other side of the room ... I have four or five engines on there two with sound but only one running at a time usually
remember that with dcc it is not how many locomotives you are running at any given time, but how many that are on the layout that determine what your current draw is. decoders draw power whether or not they are running or sitting still. this is why I recommend having tracks where you can turn off power to those locomotives not in use.
in your situation, having the command station away from the layout complicates things a little bit. normally, when I wire a layout I use one wire size, 18 guage, for everything. but in your case you'd probably want the connection from the command station to the layout to be much heavier in order to minimize current loss due to wire resistance. once at the layout itself I personally would switch to 18.
why 18 guage you ask? 18 is small enough to solder to the side of code 83 or code 100 rail, yet large enough that current loss due to wire resistance will not be a problem on a smaller layout. if you plan your wiring you can run your heavy guage bus from a terminal block under the center of the layout, and run all of your feeders from this node. you can keep all feeders under about 6 feet in length on a 4x8 layout if you do this.
j ward ... got you. I have 4 engines right now and with the lights according to info I read they probably only draw about a quarter amp each. my command station I believe can provide 3 amps. I tried looking for a specification on 18 gauge and everything i've found says it can handle up to 6 amps. to be conservative though (and to ensure the wires don't heat up) I bought 18 gauge and 12 gauge. i'm running the buss with the 12 gauge and each feeder is 8 inches from rail to buss. I personally think it is major over kill but the reason why I posted is I have no experience so i'm basically going with all of your recommendations (for the most part). The NMRA i think recommended 10 gauge for buss wire and it was only a couple dollars more but my soldering iron cant easily solder that thick of wire so that is why I wanted to use 12. As it is i have to clip off a couple of strands just to get the wire to be able to fit in to the connections on the back of the command station. thanks for your input though and your right soldering 18 to the rails is pretty straight forward. I was hoping to be able to use 22 gauge because that is REAL easy to solder to the rails.
Wire resistance? Should not have any! Connections yes ,if not soldered correctly or not at all. 0.2 ohms can be considered normal per connection. Resistance goes up with temp.So if your locos mechanism is not maintained it will pull more amps to operate and heat up.If not vented properly along with the high switching rate of say a Tsumani sound decoder you will pull more and take the chance of finding that bad connection somewhere if not solder correctly or not at all in the loco ,wiring connections or rail connectors.
I also had some issues with communication with Dynamis this was due to cracked solder joints in the circuit boards in the hand held and the receiver possibly due to the lack of lead in the solder they use now and or a little rough handling. Baked the boards in the oven stripped down completely of everything that would come off at the lowest oven setting for about 5 minutes on a cookie sheet with foil on it untill the smell of electronics that was heating up(If anybody has smelled fried smell of electronics) electronics .That is when they come out of the oven. This was a last ditch effort to fix it and it has worked flawlessly since. Found a article about somebody dong this with a pc motherboard that had success.
Johnny
Y ah ... i mean my solder joints are real good I'm testing resistance from one part of rail to another part and I'm getting 1.8 ohms consistently. If I test from rail to feeder wire I'm getting 1.8 ohms so I mean there is virtually no resistance measurable being added by the wire.
Quote from: Vizzin72 on August 13, 2016, 10:03:24 AM
As it is i have to clip off a couple of strands just to get the wire to be able to fit in to the connections on the back of the command station.
This would seem to me, to defeat the purpose then of using that particular gauge. Why not use the next smallest gauge wire then?
I know there are a million writings out there about wiring; they should all make note we are not talking about Transformer Power Lines here that are bringing electricity to cities and homes. We're talking a few feet, maybe a few yards, not miles of wire. How much resistance builds over several feet between 18 ga and 20 ga or even 22 ga for that matter ::)
@jbrock27, I know your question was rhetorical, and people will only hear what they want to hear. Neither you nor I will convince them otherwise. It's like beating a dead horse or talking to a rock. ::)
I don't understand the why it is, of one's choice, to do this either, other than they read on the internet, so it must be true. Therefore the "right" way. ???
Dunno.
I don't want to take the spectator view on this thread.
But just to show others how silly this all is...
(Don't take my word, research this for yourselves) I will feel better if you do.
Let's, just for example, say one's feeder lengths are 12in. (x2), so one would have 24 in. per feeder, and one's choice is to use 20 gage AWG wire.
Let's also say one's lokie is drawing 2A for a DCC/Sound equipped lokie running full speed (yes, I'm inflating that draw, most are probably less than half that) but again, just a hypothetical scenario.
Empirical data suggests that one's resistance will measure .020 ohms. Therefore one's voltage drop will measure 0.040v.
Using 22 AWG gage wire (same length, same current draw) will have a resistance of 0.032 ohms and a voltage drop of 0.064v.
0.064v drop. Not even a tenth of a volt. Negligible, miniscule, unnoticeable, undetectable, and whatever other adjective one chooses to use to describe the ridiculousness of all this.
So to those that want to wire a 4x8 layout with Romex (12-2 or 14-2) for busses, and lamp cord (16/18 AWG) for feeders, knock yourselves out. I still don't see the advantage but rather the disadvantage as the op states...
QuoteAs it is i have to clip off a couple of strands just to get the wire to be able to fit in to the connections on the back of the command station.
I'm just suggesting, IMO, even if your CFO allocates funds to do this, those same funds could be better utilized somewhere else in the general fund account.
YMMV.
I'm done with this. It's pointless to argue, there are no merits (cost vs. benefit). Again do your own research, and as always...
Good luck
James if you'll remember my original thread was asking can I use 22 gauge wire. I didn't want to use anything larger but I did because a few people with experiment suggested it. I had also noted that I was getting the same resistance from rail to rail as I was rail to feeder which means my multimeter can't even measure the difference. However clipping off some of the buss wires to make it fit is not harming anything it's not the same as say putting a 1/4 inch fitting on a half inch pipe.
The main thing here for me as with all things in life .... I don't want to have to fix anything down the road. I just booked my layout up with one feed only to test everything and it works like a charm however over time maybe somthing does out that's why I put multiple feeders in. I don't want to have to be tearing stuff apart and finding problems and fixing stuff and sticking feeders up after I have ballast and dirt down.
You're right
James, right down to the points about the horse and the dead rock. Or was it rock and dead horse? Rock n Horse? Which is smarter anyhow? :D
Quote from: Vizzin72 on August 14, 2016, 06:08:20 PM
clipping off some of the buss wires to make it fit is not harming anything
No one said it is; but why do it in the first place, instead of just using the next smallest gauge wire? You have demonstrated to yourself, the increase in resistance is immeasurable.
Quote from: Vizzin72 on August 14, 2016, 06:08:20 PM
I don't want to have to fix anything down the road. I don't want to have to be tearing stuff apart and finding problems and fixing stuff and sticking feeders up after I have ballast and dirt down.
And no one wants you to and no one want to see you have to. My attitude about Feeders is add them as you find you need them. I tried to get this concept across recently to
TM203 but he had some difficulty grasping the concept. You should anyway, be seeing how the layout runs BEFORE adding ballast (why dirt BTW?), then as you find you need to add Feeders you can. That test operation should be taking place before ballasting anyway. Even if for some inexplicable reason you later on found you needed a Feeder somewhere, all is not lost. You can clean an outside section of rail with a small brass bristle brush, use some Rosin Paste Flux and solder where you need to. Don't think that has ever had to be done before by a Model Railroader?
Quote from: Vizzin72 on August 14, 2016, 06:08:20 PM
I don't want to have to fix anything down the road. I don't want to have to be tearing stuff apart and finding problems and fixing stuff and sticking feeders up after I have ballast and dirt down.
And no one wants you to and no one want to see you have to. My attitude about Feeders is add them as you find you need them. I tried to get this concept across recently to
TM203 but he had some difficulty grasping the concept. You should anyway, be seeing how the layout runs BEFORE adding ballast (why dirt BTW?), then as you find you need to add Feeders you can. That test operation should be taking place before ballasting anyway. Even if for some inexplicable reason you later on found you needed a Feeder somewhere, all is not lost. You can clean an outside section of rail with a small brass bristle brush, use some Rosin Paste Flux and solder where you need to. Don't think that has ever had to be done before by a Model Railroader?
[/quote]
i'm testing it now ... so far so good. why dirt ? i dunno I want it to look real. my switching yard i'm modeling after the strasburg railroad in PA and there is no ballast in their yard its just dirt and stuff .... muddy water and stains from the coal.
Quote from: James in FL on August 14, 2016, 05:46:48 PM
@jbrock27, I know your question was rhetorical, and people will only hear what they want to hear. Neither you nor I will convince them otherwise. It's like beating a dead horse or talking to a rock. ::)
I don't understand the why it is, of one's choice, to do this either, other than they read on the internet, so it must be true. Therefore the "right" way. ???
Dunno.
I don't want to take the spectator view on this thread.
But just to show others how silly this all is...
(Don't take my word, research this for yourselves) I will feel better if you do.
Let's, just for example, say one's feeder lengths are 12in. (x2), so one would have 24 in. per feeder, and one's choice is to use 20 gage AWG wire.
Let's also say one's lokie is drawing 2A for a DCC/Sound equipped lokie running full speed (yes, I'm inflating that draw, most are probably less than half that) but again, just a hypothetical scenario.
Empirical data suggests that one's resistance will measure .020 ohms. Therefore one's voltage drop will measure 0.040v.
Using 22 AWG gage wire (same length, same current draw) will have a resistance of 0.032 ohms and a voltage drop of 0.064v.
0.064v drop. Not even a tenth of a volt.
Negligible, miniscule, unnoticeable, undetectable, and whatever other adjective one chooses to use to describe the ridiculousness of all this.
So to those that want to wire a 4x8 layout with Romex (12-2 or 14-2) for busses, and lamp cord (16/18 AWG) for feeders, knock yourselves out. I still don't see the advantage but rather the disadvantage as the op states...
QuoteAs it is i have to clip off a couple of strands just to get the wire to be able to fit in to the connections on the back of the command station.
I'm just suggesting, IMO, even if your CFO allocates funds to do this, those same funds could be better utilized somewhere else in the general fund account.
YMMV.
I'm done with this. It's pointless to argue, there are no merits (cost vs. benefit). Again do your own research, and as always...
Good luck
james what are you a wizard or somthing?
Hold both leads of your ohm meter together .It should be 0! 1.8 ohms is a indication of something going on somewhere .May be your meter leads.Your resistance should be 0 in the rail /wire connection .Any turn outs on your layout?
Johnny
It's the internal resistance of the meter .... I can't imagine there being zero residence through the rails that's impossible. I do have six turnouts but I measured lengths of track not connected to any of the turnouts as I was soldering several length of track together at the rail joints before placing them on the layout and the resistance was the same before and after connecting the turnouts. Thanks for your constructive input though.
As I recall, when I had been soldering 3 sections of 9" straight Atlas n/s Code 100 track together and I tested a rail with the meter, I was consistently getting something like .003 OHMs.
Your right ... You made me think ... I was actually measuring continuity on the same rail ... Across the rails I'm getting zero. I think someone had said that before "there should be no resistance". So it's all about voltage drop I guess. I suppose then resistance doesn't factor in until there is a load in which case it's proportional to the voltage and current. I suppose one cannot evaluate how adding feeders helps unless the VOLTAGE DROP is measured under load which I think is what jward meant when he said add feeders as you find it necessary
Quote from: Vizzin72 on August 15, 2016, 07:12:10 PM
I think is what jward meant when he said add feeders as you find it necessary
I had said that ;D, but I am sure he feels the same way ;D
sorry i said jward i meant to say jbrock ha ha ... your advise is always good
LOL! Maybe not always, but I thank you nonetheless :)
NO PROB ..... in summary though "emperically" i think it definitely is best to have several feeds even on my 4x8 because already with only two engines just sitting still my track voltage is lower than when nothing is on the track. what's the normal DCC track voltage 16 right? i'm down to 15.5 right out of the gate and i think after i finish soldering the other feeders it will be much closer to 16 most importantly of course when they are running and going over turnouts.
Mr. Ward's suggestion to install a switch to be able to cut off power to any section of track where you might have a loco parked is a good one. As he had said, this way, the loco is not drawing anything. I would consider that suggestion if possible. SPST Toggle switches should do just fine for that.
noted ... this would be a good time for me to do it. so what ? put an insulated joint in and then a SPST on a wire to one of the rails?
Yes, but specifically to the same rail you put the insulated joiner on (or you can cut a gap, CA glue a piece of styrene in the gap and trim once dried, but the insulated joiner is easier to work with). Also be sure you connect the wire coming off the SPST switch to bring power to the rail, to the correct side of where you have placed the insulated rail joiner/cut the gap.
nice ! thanks I will definitely do this!