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Edward

Polarity issues with Cobalt IP Digital Motors

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Having wired up 5 points with bonded stock rails so that the frog polarity would be controlled by DCC Concepts cobalt IP Digital Motors, I fitted them to the track work, with insulating joiners at the frog ends. Then fitted and wired the motors being careful to use the same terminals IE my "black" to Term1, the "red" wire to Term2 & the frog feed to Term3. (The Red/Black wires are the track feeds ,of course. )

Then programmed in the Accessory numbers. Tested & all worked correctly. Decided I should check the track feed before putting the board on its legs.

Then discovered that only the frog on the "wrong" side was getting any voltage. All the the rest of the track was giving a reading of 13.8 volts (AC). After usual panic, and trying various things, suddenly hit on swapping over the red and black wires to the motor terminals. This seems to work and the correct side of the frog is now live.

I've yet to try a loco on it as the board is still held securely in a vertical position in my trusty Workmate. And the 3 way asymmetric point doesn't have any readings at all.

 

Sorry it's all a bit longwinded but my question is I thought the IP motor would automatically choose which side to make live. ? It doesn't seem to be mentioned in the manual.So is there a proper rule to say which way round the feeds should go?

 

A second question is what are the steps to program the motor to change direction 197 with the NCE power cab? Somebody here gave the steps for giving it the Accessory Number which I printed off and works a treat (but you must let the Power Cab to fully power up each time).

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Edward

 

Sorry it's all a bit longwinded but my question is I thought the IP motor would automatically choose which side to make live. ?​ You have to determine which track feed goes to which terminal on the cobalt

This will change depending which way the cobalt faces

The 2 drawings on the LHS show the cobalts facing in different directions. The top example shows red going to term A whereas in the bottom example the red goes to Term B

( Term A & B refer to term 1 & 2 on the cobalt but I am not sure if A to 1 & B to 2 or A to 2 & B to 1)

 

It doesn't seem to be mentioned in the manual.

So is there a proper rule to say which way round the feeds should go? Short answer Maybe

Longer answer, looking at the point from the blade end, left rail is A & right rail is B & the point motor mounted as shown in the top drawing then A should go to the same terminal every time(I'm not sure which)

If the cobalt is mounted as in the bottom drawing then A goes to the opposite terminal

 

To test if the cobalt is wired correctly refer to the drawings on the RHS

 

post-28417-0-65699200-1496814219_thumb.jpg

 

As for the 3 way point  & the NCE I don't know either well enough to help

 

Hope this helps

 

John

 

 

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Having wired up 5 points with bonded stock rails so that the frog polarity would be controlled by DCC Concepts cobalt IP Digital Motors, I fitted them to the track work, with insulating joiners at the frog ends. Then fitted and wired the motors being careful to use the same terminals IE my "black" to Term1, the "red" wire to Term2 & the frog feed to Term3. (The Red/Black wires are the track feeds ,of course. )

Then programmed in the Accessory numbers. Tested & all worked correctly. Decided I should check the track feed before putting the board on its legs.

Then discovered that only the frog on the "wrong" side was getting any voltage. All the the rest of the track was giving a reading of 13.8 volts (AC). After usual panic, and trying various things, suddenly hit on swapping over the red and black wires to the motor terminals. This seems to work and the correct side of the frog is now live.

I've yet to try a loco on it as the board is still held securely in a vertical position in my trusty Workmate. And the 3 way asymmetric point doesn't have any readings at all.

 

Sorry it's all a bit longwinded but my question is I thought the IP motor would automatically choose which side to make live. ? It doesn't seem to be mentioned in the manual.So is there a proper rule to say which way round the feeds should go?

 

A second question is what are the steps to program the motor to change direction 197 with the NCE power cab? Somebody here gave the steps for giving it the Accessory Number which I printed off and works a treat (but you must let the Power Cab to fully power up each time).

 

As John KS diagram shows, it depends entirely on which way around the point motor is. So reversing the red & black wires is the correct solution.

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I had endless problems with a 3 way asymetric till I fitted a frog juicer and it's worked fine ever since .

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Thanks to John ks and to kevinims  for the answer!!  Oh dear pctrainman, it looks like I'm going to have a few problems with the 3-way.  I'm off to fortify myself with a nice cup of tea before having a go. 

 

Anybody any idea how to do the 197 code to the point motor?

 

 

Many thanks

 

Edward

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Thanks to John ks and to kevinims  for the answer!!  Oh dear pctrainman, it looks like I'm going to have a few problems with the 3-way.  I'm off to fortify myself with a nice cup of tea before having a go. 

 

Anybody any idea how to do the 197 code to the point motor?

 

 

Many thanks

 

Edward

 

Are you using an NCE PowerCab?

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This post might help when using a PowerCab (or any other NCE throttles.

 

Substitute 197 for 198 as required and you shouldn't need to set the accessory address a second time.

 

Brian Lambert's website provides a guide for dealing with three way points.

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Thanks to John ks and to kevinims  for the answer!!  Oh dear pctrainman, it looks like I'm going to have a few problems with the 3-way.  I'm off to fortify myself with a nice cup of tea before having a go. 

 

Anybody any idea how to do the 197 code to the point motor?

 

 

Many thanks

 

Edward

 

Using 197, you have to completely remove the power after sending the command. It does not need re-addressing afterwards - even though some instructions do say so. As per the link in the post above

 

You haven't said which pointwork you are using. Peco Electrofrog?

Treat the 3-way as two separate points.

Do one frog at a time and test. If it shorts, swap the DCC feed wires to the motor - as per your ordinary points.

 

The frog switch in the Digital IP is exactly that - a switch. It isn't a frog juicer type device.

 

Remember that wiring a point for DCC is no more different than wiring for DC. Either way, you have to have correct polarity to the frog.

 

Cheers,

Mick

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You haven't said which pointwork you are using. Peco Electrofrog?

Treat the 3-way as two separate points.

Do one frog at a time and test. If it shorts, swap the DCC feed wires to the motor - as per your ordinary points.

 

The frog switch in the Digital IP is exactly that - a switch. It isn't a frog juicer type device.

 

Remember that wiring a point for DCC is no more different than wiring for DC. Either way, you have to have correct polarity to the frog.

 

Cheers,

Mick

 

Thanks for the reply Mick.  Yes it's a Peco code 25 Electro frog.  Spent some time yesterday on it but still having dead spots in the stock rails. I think I am going to take it off the track and resolder the droppers etc.  Ah I thought/hoped it might be a frog juicer!  Understood about turning off the power after the reprogram.   

(...And so hefting my trusty soldering iron off I go again!   But slight delay while I have to investigate buying a new bed apparently. )

 

Regards

Edward

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Also if you are having issues with dead spots then you should ensure you are not relying on the switch rail to carry the power, bond it like making two separate points "DCC friendly" as per Brian Lambert wiring.

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Sorry for resurrecting an old thread.  Did you ever manage to sort this? I’ve been fitting Cobalt IP Digital point motors and have also had issues with shorts, I’m using Peco HOm trackwork and so the space for the modification is limited.  I’ve also been wiring them as you would for DC so that I can keep the accessories on a separate Bus and noticed that even with just having the common connected only, I get a short on with some points/motors, though not all. If I disconnect the feed to the frog, the issue goes away....bizarre.  

 

I will I’ll try wiring the motors up on the track bus and see if I still get the same issue with the frog them

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I suspect it you get a short when the frog wire is connected, the problem is that you have the common and return wires the wrong way round and should switch the wires going to the A and B terminals.

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1 hour ago, MartinB said:

Sorry for resurrecting an old thread.  Did you ever manage to sort this? I’ve been fitting Cobalt IP Digital point motors and have also had issues with shorts, I’m using Peco HOm trackwork and so the space for the modification is limited.  I’ve also been wiring them as you would for DC so that I can keep the accessories on a separate Bus and noticed that even with just having the common connected only, I get a short on with some points/motors, though not all. If I disconnect the feed to the frog, the issue goes away....bizarre.  

 

I will I’ll try wiring the motors up on the track bus and see if I still get the same issue with the frog them

You are taking the feeds for the frog switching from the trackbus? I hope you are as you need to do that with a separate track and accessory bus and must not use the frog output on the motor.

 

as said if you are getting a short the track wires are the wrong way around, 2 sec job to swap them round and cure the problem.

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Thanks for the replies.

 

i have 5 of the motors in a row next to each other. 3 are ok and 2 give problems, whilst all being orientated in the same direction and wired the same.  The accessory bus and track bus are separate.  I noticed the issue when verifying the polarity of the track feeds and initially went looking for shorts elsewhere.  I will have another look in the next day or so.

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36 minutes ago, MartinB said:

The accessory bus and track bus are separate.

 

That's good practise, but I understand that if you are using the 'frog' output on the Digital IP rather than the separate single pole changeover switch then the frog will be powered via your accessory bus while your stock rails will be on your track bus.  This means that when a train passes over the turnout, you will get current flowing between the two buses, which sort of negates the benefit of two separate buses.

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I think I have tracked down my issue to a couple of damaged insulating fishplate after undoing several soldered wires :mellow:  I’ll redo the wiring tomorrow and see if it’s resolved or not.

 

thanks for the help gents..... much appreciated

 

Martin

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Interesting to see the problem raised again.  As the OP I'm very pleased to report that the layout now has over 50 Cobalt IP motors and after following the advice given above,  no issues with polarity.  15 of the motors are controlled by the Alpha switches via the Cobalt Encoder Units and the rest by the Powercab using direct accy key and some macros. 

Only a track bus is used which feeds each motor terminals 1 & 2.  The frog wire from each point frog goes to the Terminal 3.  Recently I have fitted centre off passing micro switches to the fiddle yard points; just to make life easier but these are in addition to the accy button! 

I'm aware that there could be a potential problem in not having a circuit breaker but not sure how to proceed on that so have  "parked" it for now.

 

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