Hornby elite ERROR when two loco's on same track

[steve _thompson2]

Hello. I'm a relative newcomer to DCC chips in loco's. I've had two loco's, converted to DCC chip.
They were NOT DCC fitted or ready. They've both been programmed and seem to have accepted ok. By themselves, they seem to work fine. One, better than the other. 

My problem is, when the two are on the same track together, I get ERROR on my elite controller. This happened on the layout and when I checked on a separate length of test track.
Could this be because one is wired wrongly and is causing a short? 

Thanks for any help 

[Fishmanoz]

Given you've said they are working individually, there is no mechanism for a short just with both on the same track.

 

Do they have different DCC addresses?  You should always change all existing locos to their own addresses not being the default 03, then any new loco/decoder can be tested on 03 before it too is changed.

[Chrissaf]

Just out of curiosity. What happens when both are on the track, but one of the locos [either one, it doesn't matter] is turned around to face the other way. Do the observed symptoms change in any way. If they do, then this could be a possible clue.

 

The fact that both locos apparently work OK on their own, would appear at first to indicate that neither has a short circuit. It would also appear that the combined current draw of both locos is triggering the Elite short circuit protection.

 

I bet you haven't got a suitable AC Current multi-meter, but if you have. Put it on the 10A AC Current scale and insert it in series with one leg of the Elite feed to your test track. Now measure the current being drawn by each loco individually. Because of the nature of DCC, your meter won't read an accurate current reading, but for this diagnostic test a purely indicative reading is good enough.

 

If one of the locos is drawing a significantly higher current than the other then that is the one to investigate further.

 

If neither are drawing a particularly high current, then try to measure what both are drawing together, this may not be possible if the Elite goes into 'short circuit' protection mode before you get a chance to take a reading. If neither loco is drawing a particularly high current, then it maybe the Elite that is faulty and is triggering the short circuit protection at too low a current level.

 

You say that neither loco were DCC Ready or DCC Fitted, if they are of a certain age, does one of them have a factory DC Analogue smoke unit installed that you haven't disconnected as part of the DCC conversion. It would have really helped if you had given more information about which two models have been DCC converted ... i.e R numbers ideally, but at the very least Class and/or names.

 

You can get a cheap multi-meter from eBay. But in this instance you want to choose one that can measure at least 4 amps of current on the AC range. The bulk of the cheap meters on eBay can measure up to 10Amps on DC, but not high currents on AC, with many of the really cheap eBay meters not being able to measure AC current at all, only DC. I have however found a suitable meter with a 10 Amp AC Current capability for just under £16 UK.

 

TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

 

See also – further TIPs on how to get the best user experience from this forum. TIPs include 'How to post images' and 'How to make links clickable'.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

 

 

[96RAF]

Beware - Many DMMs have a current limit of just 200mA (AC and/or DC) and trying to do these checks will blow the internal fuse if fitted or blow the device if not fitted.

[Chrissaf]

That was precisely why I was very careful to select a specific meter to suggest. I looked at the specs.

[96RAF]

I was more concerned for folk who may already have a meter and not realise the limitations.

[Fishmanoz]

I agree with the additional qualification to my post that eventually, enough working locos on a single track will overload the controller and cause it to go into overload shutdown.  However, we are talking about an Elite delivering 3 Amps to the track and only two locos, both working.

 

We do know they are older locos as they weren't DCC Ready, and we also know older locos draw more current In general.  Even so, I would suggest that 2 locos just starting to run (not on stall) are unlikely to draw over 3 Amps.  In fact, could their decoders be drawing more than 3 in the first place?  But I could of course be wrong?

 

So next question Steve, what brand and type of decoders are you using, and what is their rated current?