Peco electrofrog turnouts with DC

[andyste1]

I'm planning my first ever layout (N gauge, DC) and am trying to understand electrofrog turnouts. Judging by the way this topic has been done to death on various forums it seems to be a contentious and confusing topic, but I'm still none the wiser after reading numerous articles!

 

The easiest option would be to leave the turnout unmodified, although I understand this has the potential for reliability issues. If I went down this route, would I need to fit IRJs anywhere? I found this article that has a good explanation of how an unmodified turnout works. Looking at how the frog tracks change polarity as the turnout is switched, I assume this will cause a short circuit where they meet the next piece of track. Perhaps not on an unpowered siding, but certainly on the mainline route?

 

I'm planning to use powered turnouts, so if I do decide to modify them, can someone recommend a good article, as many that I've found seem to be overly complicated (and electronics isn't alien to me either!). The clearest explanation I've found so far is this one, but I'm unsure if it's intended for DC, DCC or both, or whether it's applicable to peco turnouts?

 

 

 

[Dunsignalling]

Correct practice is to only feed points from the toe (single) end, so fit insulated rail joiners to the outlet tracks (all four rails) to avoid short circuits arising from the frogs being back-fed from sections beyond.

 

If you are going to motorise the points anyway, it's relatively simple to feed the frog independently (after cutting the standard links where necessary).

 

It's not vital to do so (otherwise Peco wouldn't make their points the way they do), but it's (IMHO) good for long-term reliability. If you expect to replace or rebuild your layouts every two or three years, I'd not bother. If it's a "lifetime" project with baseboards fairly permanently located, I definitely would, in order to avoid the need to rip up finished track in the event of a blade-contact failing years down the road.  

 

Just a bit of extra work now provides the insurance against the potential of much more hassle later, when you'll be older and less likely to find reaching the back of baseboards or scrabbling around underneath them easy. Murphy's law states that, even if only one of your points ever fails, it will be the one that's most awkward to deal with.

 

John

Edited November 15, 2018 by Dunsignalling

[Pete the Elaner]

It doesn't matter that this had been 'done to death', the fact that you frequently still see exhibition layouts running embarrassingly badly proves that it is a subject not understood by many & therefore a worthy question to ask.

The owners of said layouts usually don't even understand that running can be improved.

 

DC or DCC makes no difference to how you wire it. The difference is how the system reacts to a short circuit; DC will give a spark & the layout will hesitate as the controller momentarily overloads. DCC will detect an issue & shut off. Both are undesirable.

 

If the point faces a siding, then with good rail joints & clean point blades, you should be able to get away with simply feeding from the end of the point.

Getting away with something & recommending it as a good habit are 2 different things.

If you have some sort of loop, then there is a risk of feeding from the wrong direction, so insulate & re-feeding is a good idea.

As track gets older, it becomes more difficult to keep clean & oxidation builds up in rail joints, especially if the layout is in a shed, garage or loft. On a smaller layout, the second issue may not become noticeable but both are difficult to fix once the track has been laid, ballasted & weathered.

If you do have an issue at a later date, it is easier to add an extra feed than it is to add an insulator.

The low conductivity of nickel silver becomes an issue with larger layouts too.

 

The article you mention looks as good as any except they all suggest 1 thing I disagree with: the link pieces across the rails. If you are already adding wires anyway, why not use them for power feeds? It saves on having to rely on carrying current across rail joiners. You will have to use 2 different wires instead if the 1 in the diagram though.

[Suzie]

Generally you just fit two insulated joiners to the two frog rails, and since you are N-Gauge making modifications to the point can result in it falling apart so frog switching can be a bit of an issue.

 

There are three main ways of sorting the frog switching without modifying:-

 

1. Using a microswitch that switches half way linked in some way to the tiebar. This can be tricky to set up given the very small movement involved.

 

2. Using a 21W bulb in series with the frog wire. This is generally frowned upon in larger scales but given the low current involved in N-gauge should not be an issue.

 

3. Using a motor with built in frog switch that has a mid-point dead section or switches at the half way point.

 

Alternatively since you are DC don't worry too much and just make sure that the controller is at stop when you change your points.

 

 

There are two reasons for making the modifications to the points:-

 

a. Better contact to the switchrails.

 

b. Keeping the switchrails at the same polarity to the stock rails.

 

Any frog switching will sort out a. but you will need to sort out the back to backs on any problem wheels to fix b.

 

 

Anywhere that you will be feeding the same feed either side of an insulated joiner you can of course leave the insulated joiner off and use a conducting one, so dead end sidings are a good example.

 

There is nothing particularly difficult, just work through the choices and see what fits your operating requirement. 

[jpendle]

Your choice of point motor will effect the way you do things.

 

E.G. For cosmetic reasons, I use Tortoise slow action motors, I remove the springs from the points and get nice smooth slow moving point blades.

 

BUT this means I can't rely on blade contact to provide an electrical path through the points so I use the built in switch on the Tortoise to switch the polarity of the frog.

 

I would experiment with a single point and some track to see how things behave in your scenario before making any changes to either the points or the wiring.

 

AND remember a lot of the advice on here is for OO Gauge Peco points, which doesn't apply to N Gauge Code 55 Electrofrog  points.

 

Regards,

 

John P

[Junctionmad]

The rule relating to placing insulated fishplates is simple. , feed power to the tips of points , if at any stage power can be feed to the exit tracks from somewhere else ,, ie backfeeding , then you need IRJs on the two frog rails exiting the point , the number of superfluous IRJs I’ve seen , suggest people are installing them by rote

 

Dave

Edited November 15, 2018 by Junctionmad

[newbryford]

The rule relating to placing insulated fishplates is simple. , feed power to the tips of points , if at any stage power can be feed to the exit tracks from somewhere else ,, ie backfeeding , then you need IRJs on the two frog rails exiting the point , the number of superfluous IRJs I’ve seen , suggest people are installing them by rote

 

Dave

 

Possibly, but if anyone isn't certain where to put IRJs, then too many of them is less of a problem than not enough. It's far easier to connect up a dead bit of rail, rather than find a short and then create an insulated gap.

 

Cheers,

Mick

[DCB]

You can get some very odd faults with live frog points. As a rule of thumb don't use common return with Live frogs unless you want

prematurely whitened hair. IRJs are pretty much common sense, the frog changes polarity so if you have a continuous run and don't fit IRJs

at the frog end on the continuous run and bridge from the toe to beyond the IRJ it shorts out if the point is set for the diverging road.