How To Install A Dcc Decoder

Summary: Installing a multifunction decoder for the first time tin exist a daunting chore. After you've washed a couple, it will exist like second nature. This guide will help you through the process.

Read the Instructions

Many decoder manufacturers provide much more than detailed instructions on their website. Visit their site and download any manuals or other documentation they provide. Also read the instructions for DCC Conversion that came with the locomotive.

If this article is in conflict with the documentation provided with the decoder, follow the manufacturer'southward installation directions.

Outline

If the chosen locomotive runs poorly on analog power, installing a DCC Decoder will make no departure. Correct the drivetrain problems before conversion.

The post-obit outlines the process of installing a DCC multifunction decoder.

Decide the locomotive'due south stall current
Make up one's mind where the decoder volition fit in the locomotive/rolling stock
Select a decoder
1. Determine if there is a socket for decoder and select a matching decoder
2. Select a decoder that fits inside the body shell
3. Has the required electric current rating
Isolate the motor from the track pickups
Verify the motor is isolated from the frame
Install the decoder along with wiring for any extra furnishings
Exam the completed installation.

If you take a locomotive designed to meet Eu requirements, delight read this on their RFI Suppression Circuit. If the locomotive will stay in the Eu, it must comply with the regulations, which will crave a decoder designed for service in the European union.

Measuring the Stall Current

This procedure is Optional for modern locomotives. Those manufactured in recent years have much more than efficient motors and drive trains, which draw less current than older models. If the conversion involves an older product manufactured prior to the turn of the century, checking stall current is necessary.

Y'all volition demand a meter (a multimeter or an ammeter) that can measure out DC amps.
Connect the DC ammeter in series with your analog power supply and the track (come across picture on right). The ammeter is wired in series to mensurate all the electric current flowing in the circuit. Exist sure to use the terminals marked "Runway" or consult the instructions for the ability pack if you are non sure. Do not employ the "Accessory" terminals every bit they are alternate current.
Gear up the meter on the DC Amps (DCA) calibration, and set the range if needed. If the meter isn't autoranging, use a loftier range first to determine the range needed. It may as well crave connecting a lead to a specific terminal. Be aware that some ammeters may not have a fuse in the circuit for certain ranges.
Grasp the locomotive so it doesn't take off and plow the ability pack to full.
Push downwardly until the motor stalls (stops) and notation the current. This is the stall electric current. Do non let the motor to stall for more 5 to 10 seconds. Doing so can cause harm to the motor, or other electrical components of your locomotive.

Plan the Installation

Make up one's mind Where the Decoder Will Fit

Audio decoder, Northward Scale locomotive, and frame of a similar locomotive in HO.
Decoder mounted on weight
Decoder being installed in a boiler
TSU installed in an FB-2
NCE N Scale Decoder installed in a Walthers American Crane

Decoder siting is often the the most difficult problem to solve during the decoder installation. The decoder needs to be located in a place coming together several criteria:

At that place must be room for a decoder
Is it away from heat sources, such equally incandescent lamps or the motor?
It should ideally have free air around it for cooling
- Without proper cooling, the decoder could overheat and exist damaged. Some decoders accept thermal protection to prevent this - information technology will simply shutdown.
It should ideally be invisible from outside

Finding room for a decoder is unsurprisingly easier on larger models, and becomes more and more hard as the calibration (or size) decreases.

Ideally, the decoder should be located in the aforementioned area of the loco as the motor and pickups. It is possible to place the decoders in the tender of steam locomotives if needed. Some people have been successfull at installing decoders in rolling stock and permanently coupling it to the loco. However, this should exist a final resort as you volition want to change rolling stock in the future.

If a sufficiently large area cannot be located inside the locomotive, it may be possible to create infinite by removing some of the material from the torso or chassis. If the installation appears marginal, try assembling the model with plasticine or blu-tack in the space being considered to observe out how big it is with all the parts in identify.

"Due north" and "Z" judge models are considerably more difficult than say "G", just at that place are some small decoders available now. However, information technology is likely that material will need to be removed, though. See beneath for specific calibration data.

Sound Decoders

Select the largest speaker which will fit. If that isn't possible, ii or more smaller speakers will perform the same. Larger speakers accept better low frequency response, and can produce louder volume, for a ameliorate sounding locomotive. Many installs are now using speakers designed for the iPhone, which are efficient and provide good sonic performance.

A proper enclosure/baffle is needed to optimize the sound quality. A poor baffle, or none at all, results in poor or weak sound. Read the folio on speakers for more than information.

Enclosure Volume

The Enclosure should fit the speaker. Too small and the sound will be muffled, and frequency response suffers as well.

The platonic size is ane based on the size of the speaker. There should be a cubic relation between the dimensions of the speaker and its enclosure. For example, a speaker measuring 1" should have a 1 cubic inch enclosure, or 1 × ane × 1" in dimension.

The enclosure should be stiff to reduce or eliminate resonances, and securely affixed to forestall distracting vibrations.

Motive Ability Considerations for Sound Installs

Steam

Steam provides a tender, which tin can solve several problems: Decoder location, closed enclosure, and easy locating of the speaker.

For the all-time sound, the speaker cone should face out in free air. This tin be done either through the coal load, or the floor of the tender. A baffle can be synthetic if needed. The coal could be perforated with minor holes to allow the audio to escape, or a hole can exist cut into the floor.

Diesel fuel Electrics

The decoder volition exist, by necessity, installed in the carbody. Avoid locating it on top the motor, for temperature considerations. Locate it where possible in an expanse where airflow can help absurd the decoder. Speakers are frequently installed in the fuel tank, or under the roof peak fans. Over again, a baffle is required for optimum sound quality.

Select a Decoder

In one case the stall current has been measured and the available space has been found, yous tin motion onto selecting a decoder. There is alot of information available on various decoder sizes and specifications. You can see a local comparison list of decoders, however since it's make new, information technology's non anywhere near complete. You tin besides find information on various manufacturers' websites, besides as other DCC related websites.

Many decoders are made to go into a specific locomotives for a particular calibration. Delight see the scale specific article beneath.

However, it is possible (and in fact many model railroaders follow this do) to use an N scale or even a Z scale decoder in an HO gauge locomotive. Equally long as the current rating of the decoder meets the minimum requirements of the locomotive (most newer HO locomotives have a rating of 1 amp, equally practise most decoders currently in production) then there shouldn't be any difficulties using a smaller scale decoder. Considering larger scales (O, South & G) have a higher current rating simply decoders fabricated for these scales should exist used.

The decoder mandatory requirements are that it must have an acceptable current rating (i.e. tin can supply the stall electric current continuously) and that it will be small plenty. At that place are however other considerations to have into account:

Are any "accessory" outputs required? Most decoders can command one or more accessories - east.thou. lights, windscreen wipers, uncouplers, sounds.
How many speed steps are needed?
- The original DCC standard specified 14 steps: even so the steps between these are too obvious. 28 steps are unremarkably available, just at low speeds can exist discerned. Some systems offering 128 steps, which appear "stepless" to most people.

DCC Set up

A number of locomotives offered for sale are advertised as DCC Fix. This term can mean several things.

Being DCC Ready could mean that the motor is already isolated from the frame, meaning yous volition not accept to isolate it prior to installing a decoder.

It tin can also mean that the locomotive is equipped with a socket that mates with an 8 pivot connector. Simply remove the shorting plug and plug in a new decoder.

Some locomotives may have a light board with connectedness points for a decoder, cutting a couple of traces volition disconnect the motor and lighting from the rail pickups. The PCB can be left in and used as a connectedness point, or removed. The internal wiring is normally not soldered to the board, making removal like shooting fish in a barrel.

Isolating the Motor

The motor must exist completely isolated from all track pickup points. If the locomotive has a built-in command control socket, (usually advertised every bit DCC Ready) the motor is already isolated and should exist DCC ready at this indicate.

Checking Motor Isolation

See the Video.

An older model or one without a NMRA socket requires finding and eliminating all connections between the motor brushes and track pickups. Typically, this is the biggest problem people have when they get-go get into DCC. Diesel locomotives are fairly straightforward, merely with brass steam engines the mechanical pickups can exist quite ingenious and well hidden - and may accept some time and work to get these units DCC set up. Some models will have a circuit lath that routes power to the motor and the lights. You may need to cut a couple of traces to disconnect the motor from the power source. Check the instructions that came with the locomotive.

Verifying the wiring, and the motor isolation checks require an ohmmeter. A simple analog or digital MultiMeter will suffice. Set your meter on the Ohms (resistance) scale and touch both probes together. The meter will indicate a short (0 ohms), and will test your meter (and its battery) for proper operation.

The first examination should exist to decide that the wiring is right and functional. Affect ane probe to a motor terminal, follow the wire, and the other probe to the truck or wheels it connects to. Check both trucks if the locomotive has "all wheel" pickup. Do the same for the other motor terminal. Right whatsoever wiring problems, such as bad connections or cold solder joints, and then proceed to disconnect the motor leads from the power source, every bit per the decoder and locomotive maker's instructions.

To verify electrical isolation, y'all will demand an ohmmeter. Place one of the probes on a brush or ability last on the motor, and so touch the other probe to the chassis or correct rail pickup wire, then move to the left track pickup wire. If the motor is isolated you lot will read an open circuit on the ohmmeter. Move the probe to the other castor and repeat. If both tests indicate an open up circuit, the motor is isolated and you can safely go along with decoder installation.

Installing the Decoder

Earlier installing a decoder, especially if you oasis't done this earlier, please read the pages on Soldering and ESD Protection. It is vital to have the correct type of solder, the advisable flux, and a soldering iron/station suited to working with electronic devices.

Connecting the Motor

How the motor is wired is defined by the NMRA. See the folio on Locomotive Interfaces for more information.

Reference: NMRA Electrical Standard S-9

Ii. CONTROL A. Direction command by polarity reversing shall be provided. Positive potential applied to the right paw runway shall produce forward motion.

The term "right hand track" as used herein means the track to the right of the observer standing between the rail with their back to the front of the locomotive.

Make note of the wire which connects to the pickups on the correct side of the locomotive (where the engineer sits). The motor terminal it connects to is the POSITIVE (+) final, which is connected to the ORANGE wire from the decoder.

Lighting

Lighting tin be washed using incandescent lamps, or LEDs. Many decoders have track voltage outputs for their lighting, and so appropriate wiring is required.

Tips for Incandescent Lamps

When using 12-16V bulbs, nothing additional is needed. All the same, incandescent bulbs have a surge current when common cold, up to 10 times their rated amperage. For example, a 40ma seedling can have up to a 400ma surge current when turned on cold. This probably won't kill the decoder on the get-go turn-on, or even the 2nd, third, or three hundredth, but information technology volition wear on it, and could impairment it in the long run. To limit the electric current add a 47 ohm resistor in series. This isn't enough resistance to dim the lamp much, it will limit the surge and aid protect the decoder. If you can add more than 47 ohms without dimming the bulb beneath your requirements, and so much the better.

If using Calorie-free Emitting Diodes, every LED shall take a series resistor to limit the current. The series resistor can be installed on the anode or cathode side.

Testing the Decoder

Decoder Testers are available which allow you to test the decoder prior to installation, and even configure information technology kickoff.

Employ a program track the first time you test the installation. The program track limits the current, so a miswired decoder won't be destroyed by a short circuit.

Troubleshooting

One issue that can crusade issues is RailCom beingness active. Some decoders are not compatible with RailCom. Turning that feature off in your control station usually solves the outcome. If you wish to use RailCom on your layout, select decoders which are compatible with RailCom.

External Links

TCS has instructions on how to strip and can a wire for decoder installations: TCS Wire Guide
- Installation Pictures

European Websites

These sites are non in English. They may offer a page in English or crave translation.

Installing decoders in European Outline Locomotives

Decoder installations of all formats and sizes
Installation and Programming of NMRA-DCC-Decoders
Selection of NMRA DCC Compliant Loco Decoders

Different Types of Motors & How to use them with a Decoder

Motors and Isolation