I have finally completed the track work on my HO shelf layout, and was curious about adding circuit protection to the various blocks of the layout.
Sorry for the incomplete post. I’m on a smartphone and something went awry. To continue, I’m running DCC, 11’x28’ shelf configuration. Mostly one operator, sometimes two, running from 1 to 4 sound equipped locos max. I use the digitrax zephyr extra. When constructing the layout, I added gaps to isolate several blocks(4) of track. No reversing loops, just an oval shape with several sidings and small yard. I see that there are several brands of dcc circuit breakers. Any suggestions as to what would be the appropriate set up to use with the zephyr would be appreciated. Thanks!
Hi Byran,
I’m running a similar setup with the Zephyr and use Digitrax PM42. One PM42 will control 4 different power blocks and can be interfaced with the command station with a loconet cable. The Digitrax documentation is good and helpful for wiring.
Expect to pay @$80 list. It can be had for less at your favorite discounter.
Good luck and and let us know what you ultimately choose and why.
Derek
I use a Digitrax PM42. I like it because you can set both the trip current and the delay, which is handy if you ever use AR1 auto reversers.
Some folks say that PM42’s don’t work well because they’re relay-based, but that hasn’t been my experience at all.
Mine works great with multiple sound unit consists, AND the previously-mentioned AR1’s. No drop-outs, hesitation, or trouble re-starting after a short.
Derek and Stevert, thanks for the input. I looked at the PM 42 product description. Sounds like it would do what I need. Also checked out the PSX at Digital Specialties. Do any of you have experience with these units. I must admit that I don’t know the difference between relays and solid state. But that seems to be the key difference between them.
Hi Byran,
The two advantages for you, especially because you are running a Zyphyr, are one, the PM42 has a loconet connection so info can be shared with the command station. Two, one PM42 can be wired to control 4 different power districts.
And as Steve said the relay works perfect in my experience.
Derek
Derek, the loco net is a great feature. I have been more than pleased with the zephyr. Easy to operate, seems to have plenty of power. I added a ur 92 and duplex throttle. Those items worked perfectly together. So, maybe good to continue with Digitax. Thanks for your help.
Bryan,
In the case of the PSX, “solid-state” means that it does it’s job completely with electronics, whereas the PM42 uses relays which are electromechanical devices (they have moving parts).
That means the PSX is supposedly both faster and “smarter” than the PM42.
However, as I noted before, in some cases you may actually want/need to make it react more slowly, for example to allow an auto-reverser to properly do it’s job. The PM42 has a timing adjustment, the PSX does not.
And, as mentioned, there is the LocoNet aspect. I think the PSX has some rudimentary LocoNet ability, but I also think it needs external hardware to implement it. And even then it would be generic sensor messages.
On the other hand, the PM42 generates specific LocoNet messages that even tell you which section has shorted. So if you’re using something like JMRI, you can actually have your computer announce which section has shorted. No need to look around the layout for the buzzers or lights you had to hard-wire to your PSX’s!
So depending on your point of view, each device has some supposed advantages over the other, and each have some supposed disadvantages.
In my case the PM42 works perfectly, with none of the disadvantages folks often cite about it. Instead, I have the advantages of adjustable trip times and specific LocoNet capability, all at a lower cost than for a PSX.
I’ve had no problems with a PM42, even when I intentionally loaded one section with sound locos (6 or so) and deliberately shorted the track. When the short was removed, they all came up, no problems - where some people say their PM42 couldn;t recover from the inrush of ONE sound loco.
The PSX, and other things sold by Tony’s/DCC Specialties calim to have “feedback” as an option or included. Well, yes and no. They have connections that can drive input boards - so you need an additional piece of hardware to actually use that feedback feature. For Digitrax, a DS64 could be used, on NCE, the AUI, and Lenz also has an input board, just forget the number. If you are already using Digitrax, the PM42 plugs right in to Loconet and you cna have it trigger things when a section detects a short - the place for something like this might be in the corner of a JMRI control panel so you can see the status of each section. The PM42 also allows Loconet commands to power off a section. Using JMRI scripting, some block detection, and a PM42, you could make an automated staging yard that only powers the tracks when a train is entering or leaving.
–Randy
I use the PSX. I have four power districts so I bought the PSX-4 which is nothing more than 4 PSX circuit boards molded together as one.
I love the capabilities of the PSX and the fact that it is solid state which makes it faster to react and totally compatible with the rest of my system.
Not sure why the Digitrax AR-1 is being mentioned in replies unless you have reversing sections on your layout. I do, and I use the PSX-AR for that purpose.
Rich
At one time, I had AR-1 s
I’ve also got the 4-block PSX-4. I’m very happy with it. It’s been up and running for a few years now.
DCC Specialties is also making another circuit breaker, the OG-CB. It’s lower cost than the PSX models. Buried in the fine print is a caveat that says the Zephyr doesn’t have enough power to operate OG units, but perhaps the Zephyr Extra does. Anyone?
The AR-1 was mentioned because it illustrates one of the PM42’s advantages over the PSX.
If I recall, you were trying to use PSX’s with your AR-1’s, but the PSX would trip instead of the AR-1 reversing.
That’s because the PSX is too fast, and doesn’t give the AR-1 time to do it’s job. And unlike the PM42, the PSX has no trip-time adjustment.
Sure, you can go to all PSX’s and PSX-AR’s, but for a Digitrax user (like the OP), there are at least two disadvantages to doing so:
First, it’s more expensive. And secondly, you lose the native LocoNet capabilities that the PM42 has.
So yes, either solution will work. But for a Digitrax user, the Digitrax solution has some advantages the DCC specialties solution can’t match.
The OnGuard doesn’t have a settable trip current, it’s locked at 4 amps (IMO 3 amps is a better option for HO power districts). So no, a Zephyr Xtra couldn’t work with it either. The PSX has adjustable trip current, so you can set it to a value lower than the booster. PSX has adjustable trip current but no control over the delay. PM42 allows you to set both trip current and delay. You can use a PSX-AR with a PM42 but you can;t use an AR-1 with a PSX.
–Randy
Stevert, you have a good memory. I used to to have four AR-1s on my layout, each controlling its own reversing section. But, once I divided the layout into separate power districts and added PSX circuit breakers, the solid state breakers were tripping before the AR-1s could react to the short caused by reverse polarity. So, I sold the AR-1s and replaced them with PSX-ARs.
That’s what I tried to say in my earlier reply but somehow most of that
Guys, thank you all for providing some very useful and informative comments on the circuit protection. I think that I’m going with the PM 42. The capabilities of loconet, and trip adjustability are the deciding factors for me. I’m sure that the PSX are quality units and work very well, however it makes more sense for me to go with the digitrax unit. I appreciate the help each of you has given me.