DCC power consumption and when does enough become enough for the system

[ERIC ALLTORQUE]

Since i dont want to blog the specific threads and it comes up in them with models acting up where voltage and current are seeming more critical to the issue,its been discussed here in high places over tea......Since i dont want to blog the specific threads and it comes up in them with models acting up where voltage and current are seeming more critical to the issue,its been discussed here in high places over tea......

 

[Roy Langridge]

Why not post this in the DCC forum?

 

Roy

[Suzie]

What is the question?

[Bucoops]

9 minutes ago, Suzie said:

What is the question?

 

Don't know but the answer is 42.

[Hal Nail]

23 minutes ago, Suzie said:

What is the question?

Whether or not to do it.

[spamcan61]

I'm not risking burning over an hour of my life on that, anyone kind enough to provide an executive summary?

 

Edit: or does it amount to Ohm's law shall prevail?

Edited January 21 by spamcan61

[The Johnster]

2 hours ago, ERIC ALLTORQUE said:

Since i dont want to blog the specific threads and it comes up in them with models acting up where voltage and current are seeming more critical to the issue,its been discussed here in high places over tea......Since i dont want to blog the specific threads and it comes up in them with models acting up where voltage and current are seeming more critical to the issue,its been discussed here in high places over tea......

 

You can say that again!

[Philou]

Wut??

[Michael Hodgson]

23 minutes ago, Hal Nail said:

Whether or not to do it.

Do what?

[maico]

?

[Hal Nail]

9 minutes ago, Michael Hodgson said:

Do what?

No idea, they didnt say!

[The Johnster]

In fact, didn’t say twice…

[ERIC ALLTORQUE]

1 hour ago, Roy Langridge said:

Why not post this in the DCC forum?

 

Roy

Have you listened to the conversation they are having from where ive set the video? its 90% about Accurascales model current usage and only at the end does Pete conclude the other manufactures will head down the same route,its coming up time and time again that track voltage and current are crucial to good running,thats why its here.

[Bucoops]

7 minutes ago, ERIC ALLTORQUE said:

Have you listened to the conversation they are having from where ive set the video? its 90% about Accurascales model current usage and only at the end does Pete conclude the other manufactures will head down the same route,its coming up time and time again that track voltage and current are crucial to good running,thats why its here.

 

Ok watched it for longer this time. The first while is them going on about men of their age not going away for too long.

[spamcan61]

14 minutes ago, ERIC ALLTORQUE said:

Have you listened to the conversation they are having from where ive set the video? its 90% about Accurascales model current usage and only at the end does Pete conclude the other manufactures will head down the same route,its coming up time and time again that track voltage and current are crucial to good running,thats why its here.

So is he saying the AS 37 is particularly high current consumption? Doesn't seem that way from comments spread across the relevant megathread. Way below my Heljan 52s for example. 

For sure, as a general point, DCC sound equipped locus in particular are going to be fussier about DCC voltage level (not easy to measure accurately) across the track, and the capability of the controller to deliver sufficient current at that voltage.

[ERIC ALLTORQUE]

2 minutes ago, spamcan61 said:

So is he saying the AS 37 is particularly high current consumption? Doesn't seem that way from comments spread across the relevant megathread. Way below my Heljan 52s for example. 

For sure, as a general point, DCC sound equipped locus in particular are going to be fussier about DCC voltage level (not easy to measure accurately) across the track, and the capability of the controller to deliver sufficient current at that voltage.

The point they are making is the total off current draw on the locomotives,they run more than 37,s and the coach packs are maxing out the supply capability of DCC system and its often come up here that the track voltage has to be on the high side of a lot of the systems around at the moment,i guess this is why Aegis has the ability to alter it when it arrives.Is a lot of the troubles with the high spec electronic models that the current makes and models available not up to the job to run anything more than a few train set size set ups and with multiple stay alives to charge its putting strain on the layout control system.It seems folk are paying to buy multiple models and thats fine but need to understand they need to spend good money on a high spec control system to keep up.In not getting at Accurascale and knowlege is helpful to us all from as many sources as possible to iron out issues.

Note..... going by the above comments being a moderator here must be like directing a carry on film.

[Roy Langridge]

56 minutes ago, ERIC ALLTORQUE said:

Have you listened to the conversation they are having from where ive set the video? its 90% about Accurascales model current usage and only at the end does Pete conclude the other manufactures will head down the same route,its coming up time and time again that track voltage and current are crucial to good running,thats why its here.

Yes, and this is not an Accurascale problem, it is a problem with the laws of physics and people expecting them not to apply to their models. 
 

I have watched the discussion here with a mix of sadness and frustration. DCC is fantastic, but it it needs to be correctly used. How many people with large layouts have DCC districts with power supplied that is fit for what they expect to power in that district? Probably few, far more have a couple of feeds and probably 2-3 amps and expect to power a small town…

 

As I said, this problem is not of Accurascale’s making, it is a lack of understanding by their customers, and it will be seen across a wide range of models from various manufacturers as the spec of those locos improves. I, therefore, consider this more relevant to the DCC forum than here under a specific manufacturer. 
 

Edit: the highest demand for power I have had is a sound fitted Heljan 47, Accurscale locos going nowhere near it. 
 

Roy

Edited January 21 by Roy Langridge

[Free At Last]

At 50:30 Pete has got a stick in his ear scratching around and then at 51:05 he puts it in his mouth.
Was it Kylie's earworm he was getting out of his head.

[NIK]

Hi,

 

I think the bit about Accurascale coaches was they drew 30?ma for 20 seconds on so on DCC power up after a period with no power to the track. I guess the problem is 10 coaches makes 300ma draw and then there is the short startup current of the main capacitors of sound fitted locos and together they appear to have tripped 3 amp district cutouts on their layout (assuming all accessories and their  decoders are powered from a separate supply).

 

Many years ago for Beggarwood Lane, a 'large' OO DCC layout I did some calcs which included trains double headed by big Heljan diesels and concluded we could get away with a 5 Amp command station  and three power districts with 3A district cutouts (accessories and accessory electronics powered from a separate supply). The power districts were divided not by baseboard but by track so a train was unlikely to span two districts on DCC power up. Dividing a fiddle yard power districts by baseboard or baseboard groups has some merits if the layout is very big.

 

My calcs did not include coaches with lighting and Accurascale Mk1 coach stay alives since they were not around then. The calcs did not include the surge current of sound locos on DCC power up either.

 

Regards

 

Nik

[maico]

They should consult miniatur-wunderland who have 15km of track and over 1500 DCC HO train movements a day. Energy input every 150 to 200 meters using Marklin 3-rail, Peco code 75 in the American section, and some Roco and Fleischman 2-rail track.

 

Edited January 21 by maico

[Damo666]

To narrow down the point @ERIC ALLTORQUE is trying to raise here (if I understand him correctly) is at 42: 00 into the video, not where the link starts. I listened until I got to 56min in.

 

Salient points for me were:

• 26 coaches (with lighting). I’m not going to have that any time soon.
• It’s a large 90 foot layout.. Much as I’d like to, I’m not going to have that either.
• And most importantly, they acknowledge (@48:10) that all the Accurascale stuff “isn’t production ready, are samples” which will be taken back to Accurascale for them to sort out issues prior to production.

[MichaelE]

I noticed greatly improved operation when I switched from an NCE Powercab to the ESU Cab Control.

 

The NCE only puts out 2A constant with a 3A maximum. Not having anything to compare it to, I thought I didn't have enough drops. No. It was the NCE unit.

 

When I bought the ESU Cab Control and upped the amperage to 4.5A trains suddenly started running smoother without stops or slowing. Headlights and coach lights were brighter without flickering, and overall operation was actually fun again. 

 

In addition, the NCE unit will strain to put 12 volts on the track, whilst the ESU unit is adjustable for voltage and current. I am running 17VAC at the railhead @ 4.5A and operation couldn't be better.

 

All but one locomotive has sound and three or four trains are lighted.

[Gray69]

The conversation was that if there is a short on the layout that took a little time to find, if all the stay alives in the coaches and locos had been drained when the power came back on, all the current draw to recharge them would then trip the power again because of an excessive power draw.

They did say that it was mainly an issue that only really affected large layouts with long rakes of coaches, but did say that if the current trend to fit big stay alives to locomotives and rolling stock was to continue, it could cause issues on smaller layouts in the future.

Accurascale were been talked about because they had these issues when running their 37, 50, 66 and 92 locos, as well as the Mk2 and Mk5 coaches.

 

It was not them having a go at Accurascale, it was a discussion about the issues stay alives can cause if you have a large fleet of locos and coaches fitted with them.

I found it a very interesting and informative discussion.

 

[ERIC ALLTORQUE]

The NCE system,theres quite a few out there and im one of them and had it for many years seems not to have the capability to produce the voltage that is preferable to run the full fat DCC layout,i would think thats why the Aegis set up has been developed to bring the handset up to date and it gives it wireless capability and thats a plus in a lot of cases. It would seem by the threads and im no different that quite a few of us have bought or have to come many of these models and thats great,but if people are buying ten plus locomotives and running twelve plus coaches on multiple trains the issue will not be long sufacing even if your not running Petes behemoth layout, especially with the other high spec locos from otheres getting close.Its probably part of the issue with the deltic 37 and 92 threads having so many anomilies with sound fitted models.Perhaps we do need Accuracab to appear.

[Pete the Elaner]

So in summary, if you have an insufficient number of boosters & power districts, you will get poor running.

 

In that case, when planning a layout, wire it with more sections than you think you need. Give each section a separate power bus, but connect them in groups you think will be sufficient. If that works well, then great. If not, then you can just separate the power busses into smaller groups.

 

That is what I did several years ago anyway after learning from others on here.