Bus Wire Questions

[DairyStateDad]

First of two posts...

For a twice-around schematic (assume the size is big enough that it's operated from the center; black represents the track)...



Should the bus wires (represented by red and gray) go around once and feed both portions of the twice-around? (Just showing one set of feeders for simplicity). ** NOTE: I understand the importance of making sure the polarity is consistent all around the track.



Or should it go around twice, too? (Feeders not shown in this example).



(I kind of think I might have asked this a couple of years ago but I can't find the post and forget the answer...)

Second question, with more illustrations, in the next post.

 

[DairyStateDad]

Second question....

Not quite the same....

Two stretches of track on this twice-around are at different levels:



Again, can a single pair of bus wires feed both?



Or should a separate set of bus wires track the upper level track more closely?



With both this question and the previous one, I lean toward the once-around for the bus and one bus for both levels. I realize that if the feeders are too far from the bus there might need to be an intermediate size wire between the bus and the feeders to reduce voltage drop.

But is it really as simple as that?

 

[logandsawman]

With both this question and the previous one, I lean toward the once-around for the bus and one bus for both levels. I realize that if the feeders are too far from the bus there might need to be an intermediate size wire between the bus and the feeders to reduce voltage drop.

But is it really as simple as that?

One set of bus wires should suffice for all your track. Your same gauge feeders should be fine with 1' or less runs.

 

[DairyStateDad]

One set of bus wires should suffice for all your track. Your same gauge feeders should be fine with 1' or less runs.

That's a relief -- the answer I was hoping for! I'm guessing even at the higher level the feeders -- which are (i don't remember if they're 20 or 22 AWG) solid [not stranded] bell wire -- won't have to run more than about 6 inches.

Thank you!

 

[bwells]

I have the same thing as you do and I used a single buss, 14 AWG solid for the buss and dropped 22 AWG solid feeders to the buss. Longest was maybe 14" but they are every 6'. You shouldn't have a problem with whatever you do.

 

[DairyStateDad]

Another wiring question...

Each section will have its own bus wires, and they will connect from one section to the next.

Option 1 would be to put a terminal strip at each end of a section, then basically connect the terminal strips from section to section with short "jumper" wires.

Option 2 would be to put connecting plugs at either end of each section's bus wire.

I'm leaning toward Option 2. Any reason to be cautious?

I have seen all sorts of connection plug systems at Home Depot... any particular kind I should avoid?

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[DairyStateDad]

I have the same thing as you do and I used a single buss, 14 AWG solid for the buss and dropped 22 AWG solid feeders to the buss. Longest was maybe 14" but they are every 6'. You shouldn't have a problem with whatever you do.

That's great news. Thanks!

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[jim81147]

Erik , I would opt for the terminal strips with short jumpers. My (very limited ) experience with attaching plug connectors to solid 12 ga wire was not all that desirable . You could make the short jumpers out of stranded wire and use crimp on connectors that way the jumpers are flexible enough , yet you have the convenience of the simple screw lug ends .

 

[DairyStateDad]

Actually, I'm using 14 awg stranded for the bus, although I don't know if that makes a difference where your suggestion is concerned, Jim.... The solid is just for the feeders.

I certainly can see the security in the terminal strip option. ...

 

[Logger Mike]

Another thing to ask is: how long is the total length of your Track/Buss......after a certain length (I can't remember at this moment), you nee to bump up the gauge to 12-ga....ill look for it later and let you know the max recommended use for 14. Also, you didn't say if you're using DCC or DC.


Logger Mike,
Charlotte, NC Area

 

[DairyStateDad]

Another thing to ask is: how long is the total length of your Track/Buss......after a certain length (I can't remember at this moment), you nee to bump up the gauge to 12-ga....ill look for it later and let you know the max recommended use for 14. Also, you didn't say if you're using DCC or DC.


Logger Mike,
Charlotte, NC Area

The layout is roughly 8 feet x 11 feet, So roughly the whole length of bus wire is 40 feet. Everything I've read has said 14 awg is adequate, especially if the power is positioned about in the middle of the run, so that the current travels maybe 20-25 feet in either direction at most.

But, if you have other information, I definitely would like to take a look at that. So I appreciate the heads-up.

And, DCC.


Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[roofintrash]

You should be fine with what you're planning. I have 12x24 with the same wire gauges and have no issues.

 

[Logger Mike]

Let's see....((8x2) x2) + ((11 x 2) x 2) /2 = (32 + 44) / 2 = 38' +/- from each end to Power supply.....assuming you're not putting the rails on the absolute edge of the layout, you're about at the max suggested bus length for 14ga. Again, assuming DCC, if it where me, I'd go to 12-ga, just to be safe of not having any significant voltage drops, especially if running multiple Locos at the same time. Also, I'd recommend twisting the main buss a minimum of 1 twist per ft to cut down on interference.

Here's a link with some good basics for wiring for DCC....http://atsf93.qstation.org/Wiring.pdf

Another good source is "WiringforDCC.com"..... Really breaks down stuff to easily understand.

Good Luck...

Mike


Logger Mike,
Charlotte, NC Area

 

[DairyStateDad]

Let's see....((8x2) x2) + ((11 x 2) x 2) /2 = (32 + 44) / 2 = 38' +/- from each end to Power supply.....assuming you're not putting the rails on the absolute edge of the layout, you're about at the max suggested bus length for 14ga.

Thanks for the links -- I will check them out -- but I'm puzzled by your math.

8 feet x 11 feet translates to a total perimeter of 8+8+11+11 = 38 feet. So if the bus wire just goes around once (see earlier posts), we're talking a bus wire run of 40 feet or less for the entire layout; with the power halfway between, current is going 20 feet in each direction. Am I missing something?

In case it's helpful to the calculation... I expect to mostly operate solo, but based on the size of the layout and the basic operating scheme, I would think it wouldn't run more than 3-4 locos at a time if there were a fully staffed operating session.

 

[Logger Mike]

Yes, you're correct....I was stuck on the mind set off running a buss under the entire loop, rather than your OP.....MY BAD.....either way, there is some great info in those links.

M



Logger Mike,
Charlotte, NC Area

 

[DairyStateDad]

Yes, you're correct....I was stuck on the mind set off running a buss under the entire loop, rather than your OP.....MY BAD.....either way, there is some great info in those links.

M



Logger Mike,
Charlotte, NC Area

Definitely is. Thank you for them!

 

[DairyStateDad]

So, with the bus wire connection question... Since the layout isn't intended to be taken down and put up a lot, I guess I will go with terminal strips and jumper wires rather than a plug connection. (And it occurs to me that if I use terminal strips with some extra posts on them, I can later run some additional bus wire branches in certain places where they might be needed.... I hadn't thought of that until just now.)

 

[Logger Mike]

Something else you haven't mentioned is how many and where you may be having turnouts...if your going to have them...then Term Strips are definitely the way to go....makes it much, much easier to isolate shorts. Takes a little planning, and time to set up the power from the main buss, but much faster to connect to the feeders...at least to me.....plus if you decide to change things later and have to "cut" feeders, you won't have the suitcase connectors remaining around unused....just my 2 cents.


Logger Mike,
Charlotte, NC Area

 

[DairyStateDad]

Something else you haven't mentioned is how many and where you may be having turnouts...if your going to have them...then Term Strips are definitely the way to go....makes it much, much easier to isolate shorts. Takes a little planning, and time to set up the power from the main buss, but much faster to connect to the feeders...at least to me.....plus if you decide to change things later and have to "cut" feeders, you won't have the suitcase connectors remaining around unused....just my 2 cents.


Logger Mike,
Charlotte, NC Area

Oooh --- Great tip -- especially since several of my turnouts will be controlled from more than one point (I will mostly use PECO machines).

 

[Hawkesburytrain]

Let's see....((8x2) x2) + ((11 x 2) x 2) /2 = (32 + 44) / 2 = 38' +/- from each end to Power supply.....assuming you're not putting the rails on the absolute edge of the layout, you're about at the max suggested bus length for 14ga. Again, assuming DCC, if it where me, I'd go to 12-ga, just to be safe of not having any significant voltage drops, especially if running multiple Locos at the same time. Also, I'd recommend twisting the main buss a minimum of 1 twist per ft to cut down on interference.

Here's a link with some good basics for wiring for DCC....http://atsf93.qstation.org/Wiring.pdf

Another good source is "WiringforDCC.com"..... Really breaks down stuff to easily understand.

Good Luck...

Mike


Logger Mike,
Charlotte, NC Area

Thanks for the links Mike
So what you're saying is that my 14 gauge stranded wire is not the right gauge for my 170' double line layout which will run maybe 5 loco's at a time? (no lights and tortoises will use this wire, they'll have a separate one)