The Life Span of a DCC Decoder


Greg@mnrr

Section Hand
This is directed to the modelers using DCC systems, but the DC guys may find the subject interesting. I run a Digitrax DCC system with six throttles on my modest layout and I'm usually the sole operator. I disconnect the unused throttles from the Digitrax LocoNet Interface to kill all internal power to the unused throttles with the only reason being is why have them use some electrical power if not in use, even if the electric power drain is so minor?

Now on to DCC decoders. I was reading an article in the February NMRA Magazine in the Mail Car column about DCC decoders. A modeler wants to isolate the storage tracks on his layout to prevent the parked locomotives from consuming electrical power. The Editor spoke of DCC system start up issues with locomotives that are equipped with energy storage devices and their large inrush of current when first started.

The closing reply from the NMRA Editor was simply even through the locomotives maybe silent, they are still powered. And while powered they are generating heat and heat kills electronics and thus reduces the life of the decoders since they only have so many given hours of life. Still, the choice of powered or non-powered tracks is a personal choice said the editor.

On my layout, many locomotives are stored in the Saxeville Interchange and while silent they remain powered. I often thought about the heat factor with decoders, but never gave the subject any serious concerns. Prior to my retirement, the Facilities Department and Public Safety Departments had computers and servers running 24/7 and I replaced several computers only because of software upgrades and not due to PC failures. Comparing a PC to a DCC decoder is not apples to apples since a PC has an internal fan for circulating cooling air. Many of our decoders are installed above a heat producing electric motor and the motor or the decoder do not have any type of cooling other the latent air surrounding the decoder.

I can think of many household electronic type items that run 24/7 like door bell transformers, cable boxes, wall chargers, home alarms, fish tank aerators and many more. Most without any form of cooling. When was the last time you replaced a door bell transformer?

Recently, I test ran a Broadway Limited locomotive without a shell and the motor was warm to the touch after several hours of operation. Not hot, but never the less still warm. Its DCC decoder sat directly above the motor and I'm sure it was warmed by the motor generated heat along with any heat the decoder produced.

Personally, I never had a DCC decoder failure other than the "Blue Smoke" occurring after incorrectly installing a decoder.

What is your opinion or experiences with decoder or throttle failures and do you keep locomotives on powered staging tracks or spurs when the locos are not in use?

Do we need to be concerned about our DCC locomotives' decoder life spans reduced due to heat generated while idle or even while operating?

Thanks.

Greg
 
Last edited:
Greg, mostly it’s the inrush current that will shorten the lifespan of almost any electronic component. Not exactly the same thing, but I’ve noticed our shop lights which are on 10 hours per day have a significantly lower failure rate than identical lights in the bathrooms, which are turned on and off many times per day.
 
I don't see running electronics for long periods of time being a problem, not at all ..
Even though inrush may be higher with stay alives, as long as the sum is not over the capacity of the wall wart / power supply .. and temperature ?? if they are 'idle' there should be little [if any] increase there .
 
I've never had a decoder fail, either. All my storage tracks where locomotives (& Trains) are stored have switches which turn off the track power when not in use. I never leave a loco on a powered track, unless it is in use.
 
The Editor spoke of DCC system start up issues with locomotives that are equipped with energy storage devices and their large inrush of current when first started.
Yeah but, that has everything to do with the stay alive capacitor and very little to do with the decoder proper.

I can think of many household electronic type items that run 24/7 like door bell transformers, cable boxes, wall chargers, home alarms, fish tank aerators and many more. Most without any form of cooling. When was the last time you replaced a door bell transformer?
Apples and oranges. Most of the devices you mention are electric not electronic, the exceptions of cable boxes and alarms are engineered to be on 24 x 365, while decoders are not. Also neither of those are driving a load like a motor.

What is your opinion or experiences with decoder or throttle failures and do you keep locomotives on powered staging tracks or spurs when the locos are not in use?
No, all of my failures have been while in service.

Do we need to be concerned about our DCC locomotives' decoder life spans reduced due to heat generated while idle or even while operating?
I personally don't think so, but I still turn storage tracks off - just to save electricity. DCC power is relatively expensive.
 
Last night, at my club, one of the other members had a Digitraxx decoder release it's smoke with only the short warning of jerky movement. Apparently had had it for quite some time.
 
I don't think I've been running my stuff long enough to hit against any limits, and I've never had a decoder burn out in use -- just in fiddling/installing them when I make a mistake. I leave the tracks powered as of now.

I am on N scale so the motors may generate less heat (or more?)
 
'I've had one burn up after a derailment-caused short, and two "infant mortality" failures, one total, and the other where the motor driver worked, but the sound section was dead. Manufactures replaced all three under warranty.
 
I asked the Help Desk at Digitrax about keeping DCC locomotives on live tracks and if the decoders produce any heat and here's my answer.....

"It will not shorten their live.
Yes, decoders generate heat."
Please note that all tickets are Administratively Closed after a response is made. If further communication is required, please reopen the ticket instead of creating a new one.

Greg
 
I have decoders that are 20 years old. They still work. All of my failures have been in service, and I lost one to the Proto 2000 PA unit motor inrush current issue, and a couple to wiring mishaps/mistakes. It's more likely that older decoders will be replaced to update features than because of casualties, at least with me.
 



Back
Top