DecoderInstallation1

Decoder Wiring:

A guide to quality installation part 1

“Basic Decoder Wiring Rules”

Decoder installation is well described in worksheets packed with SOME brands, but others assume far more knowledge than users really have!

So…We’ve drafted a few “basic” rules that will guide new DCC’ers and perhaps remind seasoned installers, about good “installation practice”. As with all good “techniques” there are a few basic rules, a few important tools, and a couple of important checks to be done before the work begins.

Strange thing with lists – again we have ten subjects, five “preparation and resources, five “tips and techniques”.

We hope you find them useful…We’ve separated them into paragraphs which effectively group common issues. Feel free to copy or download them if you find them helpful, and pass them on to any “new DCC’ers” that they may assist.

Please note that this section is a “Primer” only and a guide to the important issues. You will find more comprehensive notes on areas such as specific loco installs and specialised subjects like loco lighting elsewhere on the website.

If you find these tips useful, Email us and let us know. If you have a suggestion, criticism, change or other useful data, Email us, and we’ll do our best to integrate it into the site for the benefit of all railway modellers who use DCC.

Read everything...please!

Of all the questions I receive by phone or in the 100+ emails that arrive on my desk via E-groups and customers every day, more than 99% can be answered by reading easily available information, and thinking it through.

Please don’t misunderstand… I genuinely enjoy corresponding with you and answering questions, but I also know that many frustrated modellers that have either become “stuck” in the middle of a project, or have made an error that “let the smoke out” and destroyed a decoder could have been able to enjoy a simple install and would already be running their newly decoder equipped loco if only they had just READ THE INSTRUCTIONS and FOLLOWED SIMPLE GUIDELINES in the first place. So please…

• Read the manuals (if any) that came with your locomotive – Or - visit the makers website to look for a manual or disassembly chart if you don’t have one.

• Read the worksheet that came with your decoder. Read it properly. Much of what you’ll need is already there.

• Look at websites for installation tips – this is we hope a good example, but there are some really great “modeller” websites out there too.

• UK modellers should definitely take a look at:

http://home.intekom.com/wurzel/DCC/index.html

Several nice examples of high quality European prototype installs in several loco brands can be found at:

http://www.lolkebijlsma.com/ns2200_dcc.html.

US modellers have many resources – some of the best are hosted by Decoder manufacturers such as TCS at:

http://www.tcsdcc.com

• If you are STILL stuck email me – I’ll either respond by return with the answer, or if I don’t have it to hand, I’ll refer you to someone who does… Or so I can learn myself I’ll do the research for you and find the answers.

Use the correct tools for the job

A good set of tools makes everything easier. You don’t always need to have all of them especially if most of your locomotives are DCC ready or relatively new in design - BUT without good tools the more complex installs will become difficult.

Here are a few of the key ones, however we strongly recommend you read the whole list in detail You’ll find my personal “must have” for good workmanship and reliable performance in the section The Modellers Workbench (What, why and how are all covered there).

• A good desk lamp and excellent lighting. We can’t help with these, but we can’t emphasise enough that good lighting is really important when doing installation - you can’t afford to miss the little things when working with fine wire!

• A reasonable quality Digital Multi-meter. We have an excellent meter available from DCCconcepts. Its not a “cheapy” or the lowest cost meter but it has exceptional features and is really excellent value. Click here to see or purchase.

• A “Continuity tester”. This is an exceptionally useful tool. Rather than lights or dials it simply uses a Piezoelectric buzzer to let you know when you have a short circuit or where two contact points have continuity (ie if you clip one end to a rail and then check against the brush holders it will tell you there is an electrical path between them, or if you clip one lead to each rail when wiring, it will tell you immediately if you connect the bus to the correct rail!

DCCconcepts make these simple devices—Click here to see or purchase.

• Magnifiers or magnifying glasses. Again, not a DCCconcepts product but some things need a little magnification to help the work go well, so consider them!

• A high quality soldering Iron – Best is a “base station” type with temperature control. Expensive yes, but it will last a lifetime. We only stock the best of brands, and we will only stock Soldering irons where we have continuous availability of spare parts and spare tips. We guarantee any soldering Iron we sell is as good as it gets, and strongly recommend that you take a look at our range Click here

• High quality Solder. Yes, I regard it as a tool as good installation work is impossible without it!) My personal favourite is our own “Sapphire 179” solder which flows beautifully and has a rapid solid-to-liquid melt transition which makes it nearly impossible to get a bad joint! Click here for more details, or to purchase some and find out for yourself what a huge difference there is, Click here

• Quality wire Strippers. We recommend the screw adjustable type . I was given a pair by an electronics designer 20 years or more ago. I’ve used them ever since: they are truly excellent…. and they NEVER wear out! They are perfect for stripping droppers or the finest decoder wire. (And the super sharp cutters we’ve added to the design between the stripping grooves mean one tool does two jobs).

We couldn’t find a good source of these anywhere.

However we are so convinced that they are the best there is that we commissioned our tool makers to re-create them exclusively for us, so they are now Available from DCCconcepts at a far lower price than you'd expect.

Click here to see them! If you buy, We are certain that you will soon wonder how you ever did without them!

Always use the best materials

It’s hard to do a great install without a few specialised items that are actually quite commonplace. Here are a few I use everyday. A fuller explanation of most items in this list is given in the section “Useful materials”

• Kynar Wire. I love this stuff... Want to learn more about it? Click here

• Soldering Iron Tip Reviver. This little tin contains a real “miracle cure” for soldering difficulties. I guarantee that you will find soldering easier and better if you use it. For more details. Click here

• Soldering Iron Tip Cleaner. This tip cleaner eliminates the temperature variation associated with the wet sponge approach and does a better job as well! To see one of these, Click here

• SHRINK tubing. With all installations, insulation of wiring joints becomes important – the slightest touch of a wire to the chassis can destroy an LED or decoder, and many “Mystery” or intermittent faults are caused by the wire that’s inched or moved by the body shell when its installed resulting in it contacting somewhere it shouldn’t be. One pack contains enough shrink tube for many installations. To see an image or purchase some Click here

• There are many more “Useful materials” that can make the difference between a failure, a good job and a great one. Please DO take a detailed look at the whole range of DCC installation accessories

Basic Universal pre-check & pre-install tweaking

This may NOT be quite what you expected…. However, looking at the decoder comes later... There are several other important things to check first!

(a) For DCC-Ready locomotives, Remove all the suppression capacitor(s) if they are fitted.

Please note – steam loco’s usually have only one or two, but recent diesel locomotives may have three on their PCB. . IGNORE all the talk about C-tick and suppression – the decoder will have enough onboard protection to cover this issue properly – but the decoder will NOT work its best if you leave the capacitor in – and some brands (Bachmann stands out) are nearly uncontrollable with some decoders fitted if the capacitor is left in place – ditch it!

Minimum fuss – you will have to un-solder any “chip” type capacitors, however you can simply snip one lead of the more conventional ceramic disc type. Just cut one lead with the side cutters. (Best method however is to remove all of the suppression components - with the soldering Iron.)

Please note that there is NO need to add a wire link when only the capacitor is removed, in fact you must NOT do so as it will create a short circuit across the motor. (The capacitor is installed across the motor leads and not in series with them).

FYI, the most common configuration on a loco also includes two “inductors” , one in series with each of the motor leads in addition to the capacitor across both motor leads. These Inductors have little or no effect and can be safely ignored and left in place

However be aware if you DO choose to remove them you will need to either replace them with a plain wire link OR wire the decoder outputs (Orange and gray) directly to the motor. (Inductors are easy to spot – they are usually long and round with fine wire wrapped around them)

(b) Thoroughly check the pickups.

Check that all wheels that have pickups actually DO pick up power correctly. EVEN ON NEW LOCO’S. Invert the loco and, using a multi-meter OR a pair of wires attached to a normal DC controller, check that each wheel really does pass current to the pickups. Test every wheel combination. Even the best install will NOT perform well if pickup is not good.

(c) Check the integrity of the DCC socket and make sure a careless manufacturer hasn’t placed it dangerously close to the chassis block!

Check first that the decoder socket has not been badly soldered when the loco was manufactured. It is surprisingly common to find that solder or copper wire “threads” bridge the gap between pins on the decoder socket.

This doesn’t affect the loco on DC but when you add a decoder, a short from any of the four outer pins to the four “inner” pins can destroy a decoder – and will the loco manufacturer take responsibility for your blown decoder? …. NO WAY!

Check that the decoder pins will not short against the chassis once it is fully inserted into the socket, Close is TOO close – body pressure just may bridge the gap – SO - If they are close, then either cut the end off the decoder pins after you insert it or insulate the area well.

I’ve seen many decoders destroyed by this design error! Again, the manufacturer will just shrug his shoulders at your dead decoder – so CHECK FIRST.

(d) Check the lighting.

There are a surprising number of supposedly DCC ready loco’s out there with bulbs that just won’t last when run on DCC voltages, and others where the lights will need re-wiring so you can use them properly with your decoder (turn on/off, set up mars lights, etc).

Incandescent lamps give off a LOT of heat if not properly fitted with an added resistor to cope with DCC voltages and they are comparatively short lived too, DO consider changing to “Daylight white” “Sunny White”, “Golden white” or red LED’s as appropriate – Its well worth the effort as better quality lighting, lower current draw and a super reliable lighting installation will result.

DCCconcepts has the worlds widest and best range of LEDs created for model railway use at excellent prices. They are very low cost to ship worldwide so to take a closer look at what is available, why not Click here and see what we mean!

WARNING – If you do not check, some incandescent bulbs will get hot enough to damage your rolling stock or locomotives if you do not either add resistance, or program the decoder to limit voltage to the bulb.

This damage will NOT be covered by the loco warranty! We strongly recommend replacing all bulbs with LED’s for better results and a longer problem free life. Whether you do this or not, we also find that some systems, especially those made in Europe, have a track voltage that is too high.

If possible we strongly recommend that you lower your DCC track voltage to approximately 13 volts if you do NOT want to modify wiring or replace all incandescent bulbs. If your unit cannot do this with internal settings, we can show you how to achieve voltage drop simply and at low cost. If you’d like to find out how, please Email us and we’ll be happy to show you.

Now—one more time:

Check the wheels again… Also be sure to check and adjust back-to back if necessary on every wheel-set. They should be a minimum of 14.5mm, and personally I’ve found consistently better running through Peco in particular with 14.75mm.

Whatever you prefer, adjust and make sure they are ALL perfect before you add the decoder. Out of gauge wheel-sets cause intermittent shorts that shorten life and confuse the odd decoder - and of course they definitely add to derailment problems.

While you are at it, give the wheels a clean with a cotton bud soaked in something like alcohol or mild thinners. Ex factory wheels can have a coating of turning lubricant or even overspray from factory weathering which will negatively affect performance. It also tends to be sticky so attracts crud to quickly spoil current collection and running qualities!

Work out where the decoder might fit conveniently: Consider wire length. Consider added lighting if any. Think about getting the body back on, and where any extra wire length might safely go.

(b) For NON DCC-Ready locomotives.

Trace the pickup wiring: Be sure you know where ALL the wires go, as a missed wire can create a “sneak” path to the decoder and destroy it.

Check the wiring between tender and loco if it’s a steam loco, or between the 2 bogies/trucks if it’s a diesel or electric… you MUST make sure that connections are maintained to all pickups for best results, so be methodical.

Dump the Capacitors / suppression parts: (see note in section for DCC ready loco’s – same problems, same results, same fix – DUMP the suppression!)

Lighting wires: In a loco designed for DC use, these can be a confused and confusing issue as they are often in parallel or series with the motor, or rely on reversal of voltage to interact on DC.

This means that almost certainly, all-new wiring, or at least a small PCB modification such as cutting or linking tracks will probably be needed in almost ALL non-DCC ready locomotives.

Be patient. It can almost always be done simply if you take your time & think it through first!

Test for brush to chassis contact: Once you are sure that you know where ALL the wires go (a diagram helps memory) take the wires off the motor brushes and then test for any contact with chassis or pickups. Hold one meter probe on the brush, then touch each wheel, every part of the chassis. Repeat for other brush.

If contact exists, investigate: You might need to insulate the chassis so that the brush no longer touches it. You may need to remove a small amount of metal to make an insulating gap. You may need to cut a tag made from shim copper or phosphor bronze that the Mfr added to the motor to create chassis contact for DC running – there WILL be a way to insulate each brush – there is NO motor that cannot be modified, and most are easier than you might think!

If in doubt – email me and I’ll do my best to help .

Now do ALL the wheel and pickup pre-checks listed above for “DCC-ready locomotives”... DON’T forget to clean the wheels well too!

——————————————————————————————————————————

MY opinion – Important Specs!
• Make sure the decoder brand is NMRA compliant, and generally AVOID stripped down cheapies.

• Stay with DCC, not train-set brands, no matter WHO claims to have made them. Think about it – if a brand that costs X makes a decoder for another brand, and they then sell it at LESS than X – what has been left out?

• Avoid “Badge engineered” decoders – (Means made by one company, sold under another companies name) Just like the “train-set brands” the same decoder direct from the primary manufacturer MUST be better value cost wise – there is one less profit margin in the way after all.

• Avoid ANY decoder without silent/supersonic/high frequency drive. Motors run sweeter, quieter, better and much cooler with a silent drive decoder. How cheap is a non-silent drive decoder if your locomotive motor lasts less time because of the coarse drive pulses – and it WILL fail MUCH sooner, you know. Silent drive is a MUST for good long term reliable performance.

• SIZE Matters – For smaller installs I’ve personally standardized on the very small TCS M-1 because it has all the features I need for my hand-built brass loco’s AND a superb motor drive with a ton of power handling. SMALL RULES when it comes to decoders – an easy fit means easy install and wiring after all!

• Look at the Warranty and backup very critically. Warranty varies from “totally Goof proof” to “until you install it”. The difference is extreme, & as we ALL make mistakes, a bit of free “Insurance” is well worth having!

• Avoid decoders with only ONE function. Apart from the fact they will NOT be silent drive, they will be limited in application. Fully functioning decoders such as the TCS T-1 have everything at the same price or lower than those “stripped down jobs” that are so often taken up by new DCC’ers, and offer better value, better performance and better flexibility in application.

• Look for DECODER LOCK as a function – it makes multiple decoder installs a breeze, and is a great aid to control for things such as “loco plus coach lighting”.

There are LOTS more issues, depending on your needs. Do YOU have an opinion on this – please feel free to email me and “add your thoughts” to the list.

OK – time to look at “The Second 5” of this list… Now we are looking for more specific issues, and planning to get the tools out and do some install work. Hope this helps!

The locomotive

It doesn’t matter whether its Z, N, HO, 00, O/7mm, G or any other scale or gauge… it MUST run OK on DC if its to run OK on DCC. That means reasonably good pickups, Wheel back-to-back set OK for smooth running on the rails and through turnouts/points, clean wheels.

It also means a clean motor (no oily build-up, clean commutator, clean slots in the commutator, good brushes, oiled gearbox, oiled axle bearings, no binding in steam loco valve gear…etc…etc… If you HAVEN’T given your loco a “Pre-DCC service” do it NOW. Before you add an expensive decoder, and before you create a problem because your loco wasn’t ready for the transition to happen.

The following is a big list that looks a bit intimidating….

I’m NOT trying to frighten you off – just give you the chance to learn what MIGHT await the unwary installer. DO bear in mind that MOST of the loco’s you will install have NO problems at all – this is just a set of precautionary checks that MAY be needed especially if your loco is “older” or “hand-made brass”. Most “off the shelf loco’s are very DCC friendly and install will be EASY.

NEXT: Take the top off and LOOK carefully. Where does the wiring go to/from. Which pickup goes to where. Are the brushes insulated OK, where can I put the decoder, what are the lights, LED or bulb – do I want to ADD more lights – where will I run the wires?

Make a simple drawing – and a list of things to do. A check list, just like the Mechanic fills out when he services you car – He does it so he can bill you as much as possible – YOU should do it because if you miss one step you could end up with a frustrating failure – or a dead decoder.

Older locos

Do check the current draw! If the motor draws over an amp, choose a 2 amp max decoder such as the TCS T Series. Service the motor and see if it runs smoother – if so it will probably also run at a slightly lower current draw. Be careful how many other accessories you add to a loco with a high current motor – A decoder power rating is always for the TOTAL of motor drive + accessories.

If the loco draws much over an amp – consider replacing it if possible – with a modern can motor. Running will get better, and your decoder will appreciate it!

Does the loco use incandescent bulbs? If so, plan to replace them with LED’s – MUCH less current draw, incredible reliability, better quality lighting, ZERO heating problems to damage plastic loco bodies or brass loco paintwork.

Is there a capacitor on the motor: If so, cut it out or remove it – it will stop good slow running, and will interfere with motor drive options like Back EMF or the TCS “DITHER”.

Does the lighting rely on “reverse of DCC” or track voltage? If so, plan to rewire so ALL lighting is via the decoder – full control, dimmable levels and a much better “realistic operational possibility” will result.

Is it an open frame motor? If so, check that both brushes can be insulated from the frame of the motor. 99% of the time this will be easy – that 100th time, consider replacing the motor with a modern “Can” motor for easier DCC conversion and of course better and smoother running.

Is the chassis used to collect power? If so, think how to insulate the motor brushes from the frame 100% reliably. Also explore pickup options – can you make insulate pickups to render the chassis dead – NOT always necessary, but a VERY GOOD idea if you hope to double-head or “Consist” the loco with others! Live “chassis to chassis” contact can MELT couplers!

Newer locos

Does the wiring use those “clips” to hold it in place? If so, plan to replace them with soldered connections – unsoldered wires are a recipe for unreliable performance!

Is there a capacitor on the motor: If so, cut it out or remove it – it will stop good slow running, and will interfere with motor drive options like Back EMF or the TCS “DITHER”. NOTE: Newer loco's may have "chip-type" capacitors (surface mount) on the PCB, and there MAY be more than one. If you are NOT sure, ask a question on a DCC E-group about that particular loco - someone will have done it, and they'll be able to tell you where to look.

Does the loco have a DCC socket – if so, DON'T assume it is OK - Sadly, Mfrs sometimes mess it up, so still check carefully to be sure there are no bad solder joints etc, before U plug in. ALSO – be aware that not all DCC ready loco’s have DCC ready bulbs in the light circuit. If you loco HAS an incandescent bulb, run it without the body on and se how hot it gets on DCC voltages – if it gets warm, replace it with an LED or add a resistor – HOT bulbs don’t last long – and DO melt plastic bodies!

Click HERE to see a range of LED’s with correct colouring for modelling use in a range of sizes (Prototype white / Golden white)

Is there a complex PCB with lighting and other functions in place? If so, and you are a bit confused as to the next step, Use the WEB to get data. Email me if you like, or do a search using Google.. for example “DCC install in Proto 2000 E7”. OR – why not join a DCC “user group”. There WILL be diagrams showing how to do the modification, photo’s too – as well as many users out there with the answer… and it’s a great way to “meet other DCC’ers” and learn about DCC too.

There is lots more to say on this subject—it continues on the next page!

Do you have any questions? No problem – just click here to email us and ask, we’ll be happy to help!

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