dcc wiring

[pharro]

hello there I am building a n guage layout and its about 8ft 5ft and i am onto the wiring stage. I have got myself some 7 x 0.2mm wire and was just wondering if this could be used for both bus and feeders. also has any one used Splice Connectors before, did they make the job easier.

[Edwin_m]

7/0.2 is OK for feeders but in a layout of that size is too small for a bus. 24/0.2 might be OK but 32/0.2 is probably better.

 

When you have wired up make sure you short each rail section together with a coin and check the command station cuts out. If it doesn't then you have too much resistance in your wire and a short circuit could just sit there getting very hot instead of cutting out.

[PaulCheffus]

hello there I am building a n guage layout and its about 8ft 5ft and i am onto the wiring stage. I have got myself some 7 x 0.2mm wire and was just wondering if this could be used for both bus and feeders. also has any one used Splice Connectors before, did they make the job easier.

 

Hi

 

I would go with Edwin's suggestion. My N gauge layout is 11ft x 8ft and I used 24/0.2 wire which passes the coin test everywhere.

 

Cheers

 

Paul

[Pete the Elaner]

Biggest gauge you can for the bus. I used mains cable.

[Guest Moria]

Theres a lot of myth and opinion about the wire, the capability to handle current, the distance etc etc, theres also a lot of fact and science and sometimes not all of that comes across in equal amounts.. the best piece of advice is the coin test.

 

If you want to check in advance.. take 2 wires that run from your booster to the furthest point away from it that you will need to feed and solder them to a piece of track.. power up and drop a coin across the tracks. If you get instant cut out.. good.. if not bad, increase the wire size

 

After all, based on where your booster is, the longest run of wire on an 8' x 5' layput could be 4', or it could be 9 and a bit feet.

 

 

On my N gauge, I have used much smaller than perhaps I should over much further than perhaps I should in some cases, but in all cases the coin test is perfect in all cases and no issues have been observed yet, either through the DCC delivery or the operation of current detectors.

 

Don't always assume, either that because the first coin test was good, the layout will be good.. coin test every section you wire up to be absolutely sure The last thing you want is either melted wire, or worse, melted loco. Interestingly. if you use huge wire for the mains bus then it will be the loco that melts. The coin test is still vital.

 

Regards

 

Graham

[Pete the Elaner]

if you use huge wire for the mains bus then it will be the loco that melts.

 

Rubbish.

 

Have you not heard of ohm's law?

The whole point of bigger wire is to keep resistance down & deliver the least distorted or reduced wave possible to the decoder. Domestic mains cable just happens to be a cheap solution.

 

Big wire is hardly going to increase the voltage. Only a faulty or mis-matched booster will do that.

[Guest Moria]

not worried about the voltage, worried about the current

 

Regards

 

Graham

[melmerby]

not worried about the voltage, worried about the current

 

Regards

 

Graham

 

The current is limited by what comes from the booster, thick cable is not detrimental to the wiring or the locos.

Ideally you want 0v drop from the booster to the loco, anything else is a necessary compromise.

A fault is a fault is a fault and will always have some negative effect, whether it is a blown loco chip or burnt out wiring or whatever, trying to limit current by adding resistance is a definite no no and is likely to make things worse.

 

Keith

[Edwin_m]

If you add resistance this will indeed limit the current, but by doing this it will stop the command station detecting the over-current and cutting out.

[Pete the Elaner]

not worried about the voltage, worried about the current

Worried about your knowledge of electricity

[devondynosoar118]

I am doing the same thing- wiring my N-Gauge layout. Not wanting to get involved in the above, just sharing my solution.

I have used mains cable for the bus wires, simply buy the grey 3 core solid that they use for sockets in houses, strip off the outer (grey) insulation by pulling out the uninsulated earth cable. You then have blue for one side, brown for the other. Use the thinner wire for your droppers/feeds. This will be reliable- in houses it lasts 50 years or more! It will be also be safe, if it'l take the load from a hair dryer or convection heater, plus the telly and kettle, it'll power locos easily! Keep the droppers or feeds short.