Points wired in parallel (dcc)

[Grande Maurice]

Hi. I'm trying to complete the electrics on my first every layout but having a few issues.

I was hoping to cut down on the number of switches i need for the points on my dcc layout by having a few wired in parallel. It'll make operation much simpler.

I have 10no. electro-frogs but also 2no. insul-frogs (it's along story but i'm stuck with these).

I've found only one diagram on-line but i can't make sense of it as it doesn't tell you which wires are which and it appears to be just for insul-frog. 

Can anyone help with some labelled diagrams? Thanks. 

[Grovenor]

Series wiring will need a high voltage, around 40 volts not generally available .

Use a CDU (Capacitor Discharge Unit) and the parallel wiring will be fine.

[Grande Maurice]

Def not going to use 'series' wiring - 'parallel' is my intended route and i have a decent CDU wired into the system. 

My question is what is the wiring diagram for parallel wiring two electro-frog points together? 

I don't understand the drawing i attached - what are the red, green, and black wires?

Also is this drawing just for insul-frog points?

I should hasten to add that all my points are either Seep PM1 (for electro-frog) and Seep PM2 (for insul-frog).

[Pete the Elaner]

The wiring diagrams you posted are just for operating the motors, so apply to both Insulfrog & Electrofrog points (Unifrog too). The extra 3 terminals on the PM1 will be for powering the Electrofrogs. You could choose to use the point blades for powering the frog, but I would recommend powering the frog from a switch.

 

I assume you want to throw 2 points for a crossover? If so, you need to wire the outside coils together in parallel & the inside coils together in parallel. The frog polarity will be opposite each other, so you can't just run them from the same switch.

Have you seem Brian Lambert's web site? It is very informative & the diagrams are useful. https://www.brian-lambert.co.uk/DCC-Page-1.html . The point wiring diagrams are about half way down this page.

 

Wiring the point frogs via switches is equally valid for DC. The only difference is DCC shuts down instantly when it detects a short. DC is more passive & allows some overload, but a short circuit is always best avoided.

[RAF96]

That would depend on which side of the point the motor (surface mount) was fitted or orientated (under-board).

[Grande Maurice]

Hi everyone. Sorry for the late reply, and thanks for all your comments. I'm afraid i'm still at a loss on how to wire these parallel points. I've attached a plan of my layout and marked the points that will be in parallel. All parallel pairs are electro-frog except one where one point is insul-frog. I need someone to tell me (or better still draw) which terminals need to be shared/linked - on Seep PM1 (EF) or PM2 (IF) motors. The Brian Lambert diagram i originally posted (above) shows cable lines but i've no idea which cable these are or which terminals they go to on Seep PM1 or PM2. To assist you i've added Seep PM1 and PM2 cable diagrams and also a diagram of the two scenarios i have. Any help much appreciated.

[Chimer]

I'm not sure I understand what you're not understanding, but I'll have a go.  First off, you're clearly operating your locos/units using DCC, but as you've posted this query in the "non-DCC electrics" section I'm assuming you're using "traditional" analogue electrics for the points.  If that's wrong, ignore everything I say and go and post your question over on a DCC thread ....

 

 

You have a power source (PSU), with a mains lead at one end and two (probably 15v) AC output terminals at the other.  There might be a number of outputs from the PSU (e.g. an old-style controller would also have 12v DC outputs for driving the trains), or it could be stand-alone.

 

You may have (strongly recommended) a CDU (Capacitor Discharge Unit) which builds up the oomph you get when you switch a point.  This has two input and two output terminals. Link the input terminals to the power source output terminals.

 

One wire (purple - let's call it the positive feed for simplicity) goes from one of the output terminals on the CDU (if using one) or directly from one of the output terminals on the power source (if not using a CDU) to your bank of control  switches.  Looking at one switch (SW A, which will have one input and two output terminals), controlling one crossover (Motors A1 & A2):

 

One wire (let's say the red wire in the parallel-wired diagram in the first post) goes from one side of the switch to the A terminal on A1, then on to the A terminal on A2.

 

The green wire goes from the other side of the switch to the two B terminals in the same way.  These are the positive feeds that throw the motor one way or the other. 

 

The black wire is the negative return from the two C terminals to the CDU (or direct to the power source if you haven't got a CDU).

 

If you are going to wire the frogs, the wire from the frog goes to the F terminal on the appropriate motor.

 

And you can ignore terminals D and E.

 

Finally, if when you connect it all up and throw the switch, the points get out of step with one another (Sod's Law says they will), switch things around so you link from the A terminal on Motor A1 to the B terminal on Motor A2, and vice versa, or take one of the motors off and reverse it.

 

I'll be amazed if Brian Lambert's explanation is not many times better, but worth a try maybe.

 

All the best

 

Chris

Edited February 16, 2021 by Chimer

[Grande Maurice]

Thank you - very belatedly for everyone's comments. I've had to leave the layout for some time due to other commitments, and only had a chance in the last few weeks to get back into it. The long & short of it is, that i've re-wired all points related wiring on the layout to install 24/0.2 wiring, so allowing more power from the CDU to reach the points (than 8/0.2 or 16/0.2).

 

The result? Well of the pairs of points i need to switch in parallel, only 1 works well. The others fire a single point whilst the other one stutters and murmurs but fails to move or does nothing at all. I've tried each point in isolation (and ensured they are well adjusted for free movement) and they all work perfectly, but as soon as they're paired up again, nothing. I've triple checked all the wiring and it's fine. And infuriatingly there's nothing different between the pair that work and those that don't. 

 

The distances are small as it's a 1.75m long end-to-end TDM layout, and most of the points sit inside a central 1m long zone. I've tried 2 different CDU's - Gaugemaster's 2.5A, and BCL (Brimal) starter unit - with identical results.

 

Any last suggestions are most welcome, as after this I'm just gonna give up on parallel switching, and re-make the control panel box (and its graphic) to allow for a separate switch for each point? It's a massive pain but at this rate I'll never get the scenic work underway.

 

 

[Derekl]

What are you using to power the CDUs? I am not sure whether that makes many difference, but my own experience with these motors was that two would throw on a 16V AC supply without a CDU with no problem, so this doesn't make sense - there must be something wrong with the power supply.

[kevinlms]

3 hours ago, Grande Maurice said:

Thank you - very belatedly for everyone's comments. I've had to leave the layout for some time due to other commitments, and only had a chance in the last few weeks to get back into it. The long & short of it is, that i've re-wired all points related wiring on the layout to install 24/0.2 wiring, so allowing more power from the CDU to reach the points (than 8/0.2 or 16/0.2).

 

The result? Well of the pairs of points i need to switch in parallel, only 1 works well. The others fire a single point whilst the other one stutters and murmurs but fails to move or does nothing at all. I've tried each point in isolation (and ensured they are well adjusted for free movement) and they all work perfectly, but as soon as they're paired up again, nothing. I've triple checked all the wiring and it's fine. And infuriatingly there's nothing different between the pair that work and those that don't. 

 

The distances are small as it's a 1.75m long end-to-end TDM layout, and most of the points sit inside a central 1m long zone. I've tried 2 different CDU's - Gaugemaster's 2.5A, and BCL (Brimal) starter unit - with identical results.

 

Any last suggestions are most welcome, as after this I'm just gonna give up on parallel switching, and re-make the control panel box (and its graphic) to allow for a separate switch for each point? It's a massive pain but at this rate I'll never get the scenic work underway.

 

 

Absolutely no need to dismantle a perfectly good control panel. We just need to work out what is going wrong.

 

First up, do you have a multimeter? This will help identify the problem.

[AndyID]

Are you absolutely sure the solenoid coils are wired in parallel (as shown by Chimer above) ?

 

If they are in series it would explain what you are seeing, either that or you are not feeding the proper voltage to the CDUs.

[DCB]

Just sounds like an inadequate Capacitor. Many proprietary CDU's are only really up to throwing one point.  They mainly stop trains slowing down while the point is being thrown where the same transformer winding is used for both traction and CDU.    The points might throw better without the CDU

[AndyID]

59 minutes ago, DCB said:

They mainly stop trains slowing down while the point is being thrown where the same transformer winding is used for both traction and CDU.

 

That may be a useful side-effect but that's not the main reason for using a CDU.  What CDUs should do is maintain sufficient current to the solenoid to ensure that it travels all the way. Some transformers are not capable of supplying enough current to do that.

[Brian]

Hi

The drawing you reproduced above at the opening post are not actual wiring diagrams, but were used to show the basic difference between Series and Parallel wiring. 

 

Seep PM1 PM2 and PM4 range of solinoid motors are notorious for needing to be accurately fitted under the point and should not be over tightened by their fixing screws either. If they are slightly out of correct alinement they frequently fail to operate correctly. So this would be my starting position to ensure they are free to move the point above.   

I would remove the pair of Seep motors from the points and baseboard and let them be still wired but hanging in free air. Then try them over and back on the switch. If they move together both ways with each switch operation then consider them as being wired correctly. Now refit one and ensure it is correctly aligned with the point above then retest from the switch. If ok refit the other one again positioning it to ensure it is directly in line with the point above.

 

Next, all Seeps PM1, 2 & 4 use the same wiring operation three pads - A & B with C as the return  So A & B are the feeds from the switch. C tab connects to the common return wire that goes back to the CDUs output Negative connection.   You can use PM1 on any point, PM2 have no change-over built in switch. PM4 has a switch plus it has a built in self lock mechanism.  The PM1 pads D, E & F are usually used for electrofrog polarity switching or sometimes for other switching requirements such as LED point position indications.   In the case of two motors operating from one switch, I usually recommend wiring each motor back to the switch rather than parallel linking one to the other. But linking will work and should do so on short wiring runs.   

So for parallel wiring, take a feed wire from one tab of the switch (outer tab) to the first motors A pad add a second wire to this and take that wire to the other motors A pad. Do the same for the other operation wire coming from the switches other end terminal to the first motors B pad. Add a second wire to this on the B and take it to the second motors B pad.    Run induvial wires from each motors C pads to the main common return wire for all motors. This run back to the CDU negative output.    Positive CDU output connects to all operation switches middle wiring connection terminals.  This is all show here if its of help?... Link to Point wiring   Scroll down a little to the Seep wiring.

  

The Gaugemaster CDU when feed from a 15/16 volt AC power supply rated at around 1.0Amp or more will be fine to operate two or more solinoid motors at once.

 

Edited February 25, 2022 by Brian
Spelling corrected

[Michael Hodgson]

Sounds to me like inadequate CDU.  The capacitor is that large black cylinder on the unit usually with white stripe on it, and it usually has the capacitance marked on it.  I am assuming you are running this from an auxiliary oputput on a conventional analogue controller, typcially marked 15/16v AC.

 

I have found in practice that the commonly used 2200 microfarad (2200 μF) is OK to throw a single point, but to do two at once reliably often needs a bigger capacitor, 4700 microfarad being a common choice.

 

Firing more than two point motors simultaneously with an even bigger capacitor is not a good idea though.  Slight differences in the electrical characteristics of individual point motors tends to mean that one draws a bit more of the current than another, and the weakest motor may not throw reliably.  In my experience you get away with it if there's only two point, but if there's more it tends to be unreliable, so you would a nummber of CDUs and a different circuit if you want to set up a whole "ladder" of points using a single switch to set a route..

[kevinlms]

41 minutes ago, Michael Hodgson said:

Sounds to me like inadequate CDU.  The capacitor is that large black cylinder on the unit usually with white stripe on it, and it usually has the capacitance marked on it.  I am assuming you are running this from an auxiliary oputput on a conventional analogue controller, typcially marked 15/16v AC.

 

I have found in practice that the commonly used 2200 microfarad (2200 μF) is OK to throw a single point, but to do two at once reliably often needs a bigger capacitor, 4700 microfarad being a common choice.

 

Firing more than two point motors simultaneously with an even bigger capacitor is not a good idea though.  Slight differences in the electrical characteristics of individual point motors tends to mean that one draws a bit more of the current than another, and the weakest motor may not throw reliably.  In my experience you get away with it if there's only two point, but if there's more it tends to be unreliable, so you would a nummber of CDUs and a different circuit if you want to set up a whole "ladder" of points using a single switch to set a route..

Many CDU's are made from 2 x 2200uF capacitors, rather than a more expensive 4700uF one. There is nothing wrong with doing that, but your CDU should tell you the maximum voltage. This might be 25V, but hopefully higher. Are you able to see this value?

[Brian]

As I pointed out in my comment in the topic "Blowing CDUs" Link   According to the images on the Gaugemaster website the two capacitors are rated at 40 volts and each is 2200uF.  When feed with 15-16 volts AC from a reasonably rated ampere power source that should easily move two Seep PMx motors. 

 

What we still do not know is what exactly is being used to power the CDU?   e.g. if a DC source is used then 12volts DC just wont do!   19 to 21 volts DC would be ok.  But that's guessing what the OP is using?  More info in detail is needed.

Edited February 25, 2022 by Brian

[kevinlms]

1 hour ago, Brian said:

As I pointed out in my comment in the topic "Blowing CDUs" Link   According to the images on the Gaugemaster website the two capacitors are rated at 40 volts and each is 2200uF.  When feed with 15-16 volts AC from a reasonably rated ampere power source that should easily move two Seep PMx motors. 

 

What we still do not know is what exactly is being used to power the CDU?   e.g. if a DC source is used then 12volts DC just wont do!   19 to 21 volts DC would be ok.  But that's guessing what the OP is using?  More info in detail is needed.

So far the question hasn't been answered if there is a multimeter available. Some test results would reveal a lot.

[Free At Last]

I find the gaugemaster cdu is ok for operating more than one seep pm1.

Here it is firing 3 and recharges quicker than I can operate the switch.
It is powered from a 24vac transformer.

 

[DCB]

36 minutes ago, Free At Last said:

I find the gaugemaster cdu is ok for operating more than one seep pm1.

Here it is firing 3 and recharges quicker than I can operate the switch.
It is powered from a 24vac transformer.

24 Volt.   That's why. Probably charges up to nearer 32 volts.

 

14 hours ago, AndyID said:

 

That may be a useful side-effect but that's not the main reason for using a CDU.  What CDUs should do is maintain sufficient current to the solenoid to ensure that it travels all the way. Some transformers are not capable of supplying enough current to do that.

With adequate wiring Caps should absolutely bang the solenoids across with a huge kick and then trail off to almost nothing. as per Free at Lasts video. With a CDU if a point switch sticks there isn't enough current to do damage, whereas with 12 or 16va applied directly the point solenoid will very soon start smoking.    In my experience Caps usually charge up to more than the nominal voltage applied.  I always leave a 100% margin, 48 volt Cap minimum on a 24v supply, They explode if abused, over charged connected backwards or sometimes when shorted, or made by Joe Lucas and used correctly.    Been there.  Done that, stained a patch of floor yellow.  

[AndyID]

2 hours ago, DCB said:

24 Volt.   That's why. Probably charges up to nearer 32 volts.

 

With adequate wiring Caps should absolutely bang the solenoids across with a huge kick and then trail off to almost nothing. as per Free at Lasts video. With a CDU if a point switch sticks there isn't enough current to do damage, whereas with 12 or 16va applied directly the point solenoid will very soon start smoking.    In my experience Caps usually charge up to more than the nominal voltage applied.  I always leave a 100% margin, 48 volt Cap minimum on a 24v supply, They explode if abused, over charged connected backwards or sometimes when shorted, or made by Joe Lucas and used correctly.    Been there.  Done that, stained a patch of floor yellow.  

The 15 volt ac output is the RMS value of the voltage on full load. The peak voltage which is what the CDU charges from is 1.414 times the RMS value and when little current is being drawn the voltage will be a good bit higher so doubling the cap voltage or even more is a very good idea.

[melmerby]

8 hours ago, kevinlms said:

Many CDU's are made from 2 x 2200uF capacitors, rather than a more expensive 4700uF one. There is nothing wrong with doing that, but your CDU should tell you the maximum voltage. This might be 25V, but hopefully higher. Are you able to see this value?

4700uF are not normally twice the price of a same voltage 2200uF so 2x2200uF is false economy, the 4700uF will also likely have less than twice the volume of 2x2200uF.

[kevinlms]

On 26/02/2022 at 07:50, melmerby said:

4700uF are not normally twice the price of a same voltage 2200uF so 2x2200uF is false economy, the 4700uF will also likely have less than twice the volume of 2x2200uF.

I have seen some CDU kits like that (maybe to make it more compact?), personally I would buy the proper 4700uF ones, even if they did cost more. They certainly used to, bearing in mind the voltage rating.

[cliff park]

I'm sorry but some of these comments make no sense. A 4700µF is not the 'proper'  size. It is what someone has worked out will give a good kick, and its size is calculated in conjunction with the resistors, rectifiers, transistors etc used in the circuit. Electronically there is absolutely no difference between one large capacitor, and two small ones of the same or similar capacitance. Note that electrolytics have a huge tolerance, often something like +40-20%, and even the best are usually ±20%, which swamps any minor differences in size. 

[Grovenor]

The difference between 2200 and 4700 is not minor. To give an equivalent pulse for two solenoids in parallel needs double the capacitance as for one, assuming that the voltage is the same in both cases.

Increasing the voltage is an alternative to increasing capacitance but may be more difficult/expensive depending on what power supplies you have available.

But if your circuit works fine with one solenoid but fails with two you need to increase one or the other.