hornby surface point motor

[Paul.P]

can anybody tell me if there is a way to test the hornby surface motor,i dont have a multimeter,the point was working fine this morning,then after about a hour,nothing,or could it be the accessory decoder r 8247,all wired correctly,again,is there a way to test the decoder without a multimeter?

[Chrissaf]

Extend the three wires (disconnected from the R8247) of the R8243 surface mount solenoid to the 15VDC Auxilliary output of your Select. Touch the Hornby Green and Black wires across the Aux output, then the Red and Black wires across the Aux output. The solenoid should throw, if it does. Then check your R8247 configuration has not been corrupted.

.

But before doing all that, first turn everything off and restart everything from scratch in case of a software glitch.

.

[96RAF]

@Chris

 

I've just tried a 9V PP3 brick battery across  Peco and Hornby surface mount motors and a normal Hornby big solenoid and with no load they all threw on that battery power.

 

What it would be like installed to a point I have no idea, but certainly on the bench it gives a positive indication of all is well (or not).

[Chrissaf]

@Rob, I would expect that with a physical point load, a 9 volt dry cell might just raise an audible click. But as I was still in edit mode with my last post, I had a re-think and deleted the references to the battery anyway.

.

Paul, when you were running your trains this morning whilst all was well. Did you, at any time, have any accidental 'short circuits' on your layout?

.

Short circuits have been known to cause Hornby R8247s to loose configuration. This more often than not requires the R8247 to be reset to factory status and re-configured. The problem is, that the Hornby Select can not reset a R8247 because it cannot write anything to the decoder CV8. In some cases the 'short circuit' glitch just resets the R8247 ports to addresses 1-4. But as you have a Select, these would have been changed by you as part of the setting up stage to addresses in the 61 to 99 range. If this is the case with yours, you may just get away with re-configuring the addresses to the ones previously configured and negate the need for the CV8 reset. But bear in mind, if a 'short' causes this to happen once, then the likelihood is that it will keep on happening every time a 'short' occurs.

.

You can alleviate problems with the R8247s being corrupted by 'shorts' by fitting a suppressor across the DCC track. The suppressor consists of a 120 ohm (1 watt) resistor in series with a 0.1uF Ceramic Disc Capacitor of 50 volt rating or more. This just gets connected across your DCC wires in close proximity to where the R8247s are connected to them. The resistor will get VERY warm, this is normal.

[Paul.P]

the point motor is fine,i connected it to the aux output as you said Chris,and it works,all reset and re addressed the decoder,nothing,so the decoder is dead,tried all ports and nothing,addressed corrctly as 61,62,63,64,the decoder is new so a case of returning it,also what size wire should i use to extend the point motors wire,thanks again

[Chrissaf]

Nothing smaller than the wire Hornby use themselves on their wiring looms.

.

Personally, I use 24/0.2mm wire (24 individual strands of 0.2mm dia wire in a common insulation sheath). That is probably a bit thicker than Hornby's wires. But there again I use Peco products not Hornby and made my own custom wiring looms.

😇

.

When you say, "addressed correctly as 61,62,63,64" did you actually go through the addressing process to reconfigure those addresses on the apparently faulty decoder.

.

Before boxing up the R8247 and sending it off. One more thing you can try. In the Select manual there is a section on 'resetting' the Select itself. You can try doing a factory reset of the Select controller itself.....worth a try.....no harm lost in doing it.

.

Did you have a 'short' at all this morning? (reference to my previous reply)

[Paul.P]

Hi Chris,yes I had a short, i have done a reset of the select but I have not tried re  addressing the decoder with different numbers, I will try that tomorrow,thank you again Chris for the advice and help, I also have found some 16/0.2 wire for extending the wires on the point motor

[Paul.P]

Not that it makes any difference as it was running fine but I had the 2 wires from the decoder into the power track as well as the 2 wires from the select, so  2 wires in the B slot on the power track and 2 wires in the A slot on the power track

[Chrissaf]

Slight misunderstanding Paul, when I said reconfigure the R8247. I meant with the same addresses 61,62,63,64 the same as you had before, just overwrite the configuration that might be corrupted due to the short with the same previous configuration. If that indeed recovers the situation, then review my comment regarding fitting a short circuit suppressor as per my previous reply.

[Paul.P]

how do you reconfigure then Chris,i did use the same numbers ,61,62,63,64,after i reset the select,but still nothing,i reset the select,so i pressume the first time i put the 61,62,63 and 64 then reset the select that was wiped

[Chrissaf]

The 61-64 addresses are held within the R8247 Accessory Decoder. The Select is completely oblivious to them, resetting the Select has no affect on the addresses in the R8247 decoders.

.

I am talking about the process of configuring the R8247s as if you are doing it for the very first time. That is.

.

Disconnect the Select from the track, so only the R8247 is connected to the output of the Select.

.

Then configuring the 61-64 addresses back into the R8247 just like you did the very first time, just overwriting the same 61-64 addresses that were previously configured but may have been corrupted. If you remember, you only had to address the first address i.e 61 and addresses 62-64 were automatically added by the configuration process.

.

Then once the LED flashing sequence (I think it is 5 flashes from memory) confirms that addressing has been accepted, then reconnect your track and test again. If you don't get the 5 flashes confirming configuration acceptance then something is wrong (maybe another indicator that the R8247 has gone faulty).

.

If this still fails to revitalise your R8247 and you have also reset the Select (which doesn't affect the R8247 addressing in any way). Then it would appear that the 'short circuit' you had earlier today has indeed damaged the R8247. These R8247's have a history of being susceptible to such damage.

.

Unfortunately the Select does not support the capability to perform a full factory reset of the R8247. To do so, can sometimes recover a R8247 from a deep configuration corruption. The full factory reset of the R8247 involves writing decimal value 8 to CV8, but the Select does not support writing CVs except the DCC Address and Acceleration / Deceleration CVs.

[Paul.P]

will do,many thanks

[Paul.P]

just reconfigured Chris and the select led flashed 3 times,decoder still not working,so the decoder is definately going back,the suppresor you mentioned,can you buy them?

[Chrissaf]

You can buy them. I bought the one made by DCC Concepts. Only used it once before removing it and making my own using the components I listed in my previous reply. I was most disappointed with the DCC Concepts one, made too cheaply from inferior and under specified components, yet grossly overpriced - see below.

.

The cost of a 100 to 120 ohm 1 watt resistor is about 12 pence and a 0.1uF 100v Ceramic Disc Capacitor is about 8 pence. The DCC Concepts shop bought one was £8 for a pack of two.

.

Note: My Resistor / Capacitor prices NOT based on Maplin prices. By all means use Maplins for the convenience, and saving P&P costs. Still significantly cheaper than DCC Concepts price.

.

Suitable Maplins components for making your own are:

D100R 100 ohm 2W Metal Film Resistor (nearest equivalent spec I could find) at 49 pence

N43CJ 0.1uF 100V Ceramic Disc Capacitor at 49 pence

[Paul.P]

thankyou Chris for taking the time to reply,as i said,no luck with the decoder

[96RAF]

From the manual

Programming:

1. Press and hold “SELECT”.The LCD display will flash “LA”.

2. Enter the first address (61) on the keypad, and press “SELECT”.The red led will flash up to seven timesduring which the decoder will be accepting the command. If the LED flashes eight times, it is advisable tore-programme the Decoder again.

3.The point/accessory is ready for use.The other outlets have been automatically coded 62, 63, 64.

 

If you connect a solenoid to port 4 of the acc decoder you should also hear it click as programmming completes.

[Paul.P]

done exactly that RAF96,nothing,my select red led flashes 3 times

[Chrissaf]

Paul,

Have posted a drawing with a suggestion on how to add the suppression components to your layout. Needs to be moderated so probably won't appear until sometime tomorrow.

[Chrissaf]

Paul, drawing as promised.

.

/media/tinymce_upload/02dc72e7ebb11497d8cfcc87c83e5217.jpg

[Paul.P]

okay,thankyou,all i can keep saying is thankyou,for your help,advice and time,it is appreciated Chris,first lot of rolling stock is arriving tomorrow,6 hornby R6760's to go behind my class 47

[Flashbang]

A typical DCC bus filter is shown in the link below.

The resistor value can be from 100 Ohm to 150 Ohm (100R to 150R) but do use a 2W or higher wattage resistor.

The drawing shows a filter connected across the end of a DCC bus pair of wires, but it can be connected anywhere across a pair of DCC feed wires - say at the terminals where the DCC arrives at an accessory decoder etc.

http://www.brian-lambert.co.uk/DCC.html#On

[Chrissaf]

My drawing and FBs drawings are very similar. Mine is tailored to your particular layout wiring as you are not implementing the DCC Bus shown in FBs.

.

The Maplin components I gave links for were for a 2W resistor. The main reason I dumped the DCC Concepts product was because their resistor was only a 0.5 W one and it got so hot it burnt my fingers and started to scorch the plastic covering. I felt it was too much of a fire risk. Hence I made my own with uprated wattage components. The resistor still has to dissipate the same amount of heat, but because it does it over a much bigger resistor surface area, it doesn't feel as hot to the touch.

[Chrissaf]

Want to learn more about why the Resistor / Capacitor can help protect the R8247's against damage caused by short circuits. Then have a look at these two web pages by Mark Gurries

Decoder Damage

RC Filter.

[96RAF]

@chris and others

The second link is much more informative as to the how's and why's and what's to be done.

Even I was tempted to lash up a filter for my 6x4' 'desktop' layout.

[Paul.P]

thankyou Chris,another thing i new nothing about,having to protect the decoders