DCC Single Slip Wiring

[turtlebah]

Hi All,

 

Having some problems with some point work wiring and i can't understand why. I've attached a picture below which shows how i have wired up a Peco Code75 single slip with seep point motors using the readily attached dropper wires for DCC use, but something bizarre has resulted.

 

As you can see from the picture below, the slip is totally isolated as it's connected to other point work at either end.

 

The seep point motors have a built in polarity switch and it's DCC controlled.

 

When i run trains along the top exit from the slip the trains run fine, indciating that the polarity switch works fine, but when i run it down the left fork, as soon as the driving wheels move over the small insulating strip within the frog on the bottom route there is no power.

 

I've tried testing all the connections etc, but it seems very strange that power is fed into one side of the frog, but not the other and that the the polarity switch within the point motor works in one direction, but not the other.

 

Short of trying a different point or changing the point motor i'm not sure what else to do. Any suggestions?

 

 

 

[10000]

My first thought was poor contact between a point blade and stock rail.

 

Have you checked continuity throughout the slip with a meter?

[Grovenor]

The wiring is correct so there is a problem with the switches on the point motors or with the continuity of the rails in the frogs. To check either you need a meter, or just a 12v lamp bulb, to check continuity.

You can then trace the connections through the circuit till you see where the break is.

Regards

[Phil S]

PRE_ OBSERVATION: ALTHOUGH this is only a 'single slip' IF YOU ARE NOT USING a Frog Juicer then you MUST OPERATE IT AS IF IT WAS A DOUBLE SLIP - which means YOU MUST change the 'other' point motor even though you are not actually using the route it sets - YOU ARE USING the ELECTRICAL setting form it !!! .. see all states at end below....

 

It would help if your diagram actually showed your connections and did not leave everything to be inferred - possibly incorrectly.  You have a yellowish block covering the lower right exit/entrance - but no explicit mention of this relevence in the text.   The upper rail in the yellow box is electrically connected to the lower rail of the upper right exit immediately above it (live frog)

We are left guessing as to how the contacts change with the switch blades on your Seep motors ... and which connections you have made there. ... is the COMMON in the centre of the 3????

 

The dropper wires are not simply provided for 'dcc use' - but are the most appropriate method of making ANY electrical connection to the FROGs (V's) - each of which are independant and may be opposites !  as well as the Crossings K which will always be opposite - and can be permanently powered as perhaps indicated by your diagram.

 The only valid inference one can take from the diagram is that the V at the opposite end of the point is 'controlled' by the point motor at the other end  - which is correct. - bit noting is shown as to WHAT it is connected to at any time!

 

A Double Slip is equivalent to 2 back-to-back Y points - and best shown on diagrams that way 8-)  - BUT with the 'confusion' that the moving blades are on the 'SPLIT Y' part and not the base.

As a single slip not all routes are valid.

The only difference about the double slip wiring beteen analogue dc and dcc is that the dcc voltage is always present - and in EITHER the same phase as the upper rail, or the LOWER rail.

(Therefore whenever a wheel bridges the frog V in insulfrog - you get an immediate short and cutout.  Here, with a LIVE frog, it must be correct (either by 2 Frog-Juicers, or by 2 preset switches) - if INCORRECT the short would occur as soon as the first metal wheel of the train crossed the insulating rail joiners onto this double slip.

 

LABEL THE DIAGRAM to AID understanding/description: 

Eg ABCD where A is UPPER LEFT, B is UPPER RIGHT   C is LOWER RIGHT and D is LOWER LEFT (in the same way a rectangle is labelled in geometry - clockwise or anticlockwise.

 

As a SINGLE slip, not all 'routes' are valid. As a Double Slip  A <> B  and A <> C are valid, D <> B and  D <> C are valid.  Switch Blade Options are Leftmotor: UP or DOWN, RIghtmotor  UP or DOWN

 

DO YOU HAVE A MULTIMETER - if so, you can verify how the V-frog sections change polarity/phase (in dcc) as the switch-rails are moved across. ??

 

TRAIN ENTERS TOP LEFT at A:     to go to Exit B (upper right) - BOTH Switch blades are 'DOWN' in the diagram to create the CURVE A <> B,   BOTH LEFT V and RIGHT V connect to  'BLACK'

Train enters BOTTOM Left at D      to got to Exit B (upper right) - LEFT switch blades is DOWN and the LEFT V needs to be connected to 'RED'  (the UPPER rails)   ...Right V remains 'BLACK'

 

TRAIN ENTERS TOP RIGHT at B  to go to Exit A (upper left) -  a repeat of the first case above - both switch blades 'Down' - and BOTH left and right V's connected to BLACK

Train enters LOWER right at C to go to Exit A (upper Left) -  a mirror image of the 2nd case -  LEFT switch Blades is UP, RIGHT switch blade is DOWN therefore LeftV= Black, and RIght V = Red

 

Train D to C or C to D not valid for a Single Slip, but for a Double Slip BOTH SWITCH BLADES 'Up' and BOTH V's connected to RED.

 

TO Summarise: LEFT Switch Blades control RIGHT V (as wired= correct)   

When Set to CURVE (lower position in diagram) the controlled V at the opposite end  is set to BLACK

WHEN SET TO STRAIGHT (upper position in diagram) the controlled V at the topposite end is set to RED

Edited May 31, 2017 by Phil S

[jacko]

I'm interested in the answer to this as I believe I'm having the same issue - a dead section between the left frog and the lower left insulating joiners. Only happens with shorter 0-6-0 locos.  Tender locos with the extra pickups don't have this problem.

 

Graeme

[newbryford]

Just a note:

 

Wiring of single slips (and other electrofrog pointwork) is not a problem unique to DCC.

The same issue applies if it is DC.

 

Cheers,

Mick

[turtlebah]

I'm interested in the answer to this as I believe I'm having the same issue - a dead section between the left frog and the lower left insulating joiners. Only happens with shorter 0-6-0 locos.  Tender locos with the extra pickups don't have this problem.

 

Graeme

 

That's exactly it Graeme. I can't for the life of me work out what I have done wrong. It doesn't short so there's no wires the wrong way round, or anything like it, just no power.

[Les le Breton]

Thank you  turtlebah, for posting the Gordian knot of single (and double,) slip wiring for turnouts.

And thank you Phil S for the erudite, Alexandrian solution.

 

 They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance.

 Terry Pratchett

[Grovenor]

Do you have a meter or lamp to test with? Then we can suggest tests that may reveal the problem.

Regards

[Phil S]

Try carefully drawing HOW you have connected the Seep Point Motor Switches to the 'Power Supply' and to their opposite-end   V's .... paying particular attention to the position of the Tie-bar (up or down in diagram) and WHICH SWITCH CONTACTS are 'connected'.

 

If it is not a ;short'; but fails to 'run' the implication is that it is open-circuit in that position ......   Each SEEP motor should have the COMMON part of the switch attched to the frog

and the other 2 contacts to the Red or Blue wiring ( 1 each ... and   'Red' when in the 'Upper' (Straight across ) position, and  'Black' when in the lower position (as shown on right switch rails)

 

BUT THE SIMPLEST WAY to get wiring correct is to spend 5GBP or a little more on a basic Multimeter !!!  ' Reasonable' ones with next day delivery on Amzon for less than 15GBP

Plenty more to choose from    But it is really the most fundemental and essential tool for any work involving the invisible substance known as 'electricity'

[Suzie]

The problem is usually the Seep contacts.This type of problem seems unique to Seep motors.

[John ks]

The close up is not a slip but I believe it shows the construction of the frog rails

Notice the tiny gap between the 2 rails that make up the frog, they may not be touching each other & rely on a welded jumper for electrical continuity.

 

 

I seem to recall someone else was having a similar problem and it turned out to be a faulty link under the frog

 

The dropper wire should be welded to both frog rails, if one of these welds fails & the 2 frog rails are not touching then only one of the two frog rails will not get power

 

Test with a lamp from a to b & from a to c. The lamp should light up both times

If it only lights up on one of the two tests the dropper wire has a failed weld

 

A quick & dirty fix would be to jam a small piece of wire between the frog rails were they meet( near the c & b in the close-up)

A better fix would requiring soldering the 2 frog rails together, but you run the risk of melting the plastic around the frog

​If the slip is new then you should considering returning it

 

Hope this helps

 

John

 

[turtlebah]

You'll all be pleased to know that i got to the bottom of the problem. After replacing the point motor and the single slip the problem still persisted with the yellow zone being totally dead.

 

Turns out that although the point was being thrown by the first point motor, the solinoid bar wasn't going all the way across to make contact on the other side, thus not switching the polarity of the opposite frog. I think Suzie above nailed it.

 

What a waste of 4hrs. On the upside i do now own a multimeter and a very useful 12v buzzer (that was a godsend whilst testing).

[jaym481]

Time spent troubleshooting always seems wasted when you hit the other end and say "that was so simple." If you find and fix the problem, don't count it as wasted.

 

You've also pointed (har-har) out a possible issue for some of us who may have had a similar problem. Your "wasted" four hours may just save me time in the future. Where do I send the cheque?   

[jacko]

It is interesting that the Seep PM1 has a much wider throw than the points themselves. However, I don't think the bar has to be thrown the full distance to actuate the switch otherwise none of my points would work. 

 I've been testing my slip and motors and have found that one of the motors gives unusual readings on my multimeter. When measuring between the  D. E and F terminals I find that with the switch thrown to D and giving the correct 15 volts between D / F, I still see around 2 volts between E/F.  throwing the switch to E, there is still only 2 volts between E/F . (0 volts between D/F)  so tonight I'll do some more testing. First I'll unscrew the motor and test it hanging free to see if it's an issue with the distance of the throw then if it's showing the same symptoms I will swap the motor. ( I'll come clean and admit that some of my motors were bought second hand from evilbay - I've since found them brand new for £4 at Hattons so little point trying to save a few coppers).

 

Graeme

[shibushe]

I have a Live frog single slip as shown.

Only one exit leg, ( Bottom Left ) in the above sketch connects to another point.

As this slip is very little used it does not have motors. ( Manual Operated)

The frog rails are insulated.

Locomotives run through it with no problem.

So what's the difference with mine against his that doesn't ?

[Suzie]

I have a Live frog single slip as shown.

Only one exit leg, ( Bottom Left ) in the above sketch connects to another point.

As this slip is very little used it does not have motors. ( Manual Operated)

The frog rails are insulated.

Locomotives run through it with no problem.

So what's the difference with mine against his that doesn't ?

I suspect that your locos have better pickups!

[turtlebah]

Just to close this one off via an update...

 

I decided the best thing to do was sack off the seep point motors and splash out on the cobalt digitals. Fixed all my problems. Unfortunately i think that the seep motor contacts are just not reliable enough for the smaller code 75 single and double slip points. It can be really hit and miss as to whether the polarity actually changes when the point is thrown.

 

I'm sure better modelers than I made a better fist of it, but I really like the plug and play nature of the cobalts. No extra decoders or wiring.