Possible?
@Hp289 posted:TVS diode 1500W 33.3V TVS at Digikey
Also, out of stock. Where is another good place that keeps these in stock?
Thanks!
Here you go.
Thank you John, can you please assist with the rest I have up there? Running to office fo rite day, I'll be back on tonight. Thx.
@Hp289 posted:PSX1, GRJohn seems to like... Have ya'll come to consensus which is "better" for our model train application? I do not have the knowledge base to pick one. And, the PSX, when it trips, how do I reset it? On the airpax, why 5amp? shouldn't I want a 7.5 or 10 amp?
Money is one of the two key factors in the decision. The PSX1 is more expensive than the Airpax breaker. The old maxim "You get what you pay for" applies here. If you'd like to go a little less expensive then use the recommended Airpax breaker, and check out @SteveH's recommended links to help you with it.
A I understand it the PSX1 can either reset itself when the excessive load (current) clears, or you can set it up to require that you push a button to reset it. For the money it should have both options. I believe as well that there's also an option to add a noisemaker that will alert you the instant it trips.
With either solution choosing the trip current is a fairly important task. Since you're not worrying about protecting the transformer (because the ZW-L is supposed to protect itself, as mentioned above) you need to be concerned about the precise current that your train will draw when it's operating, considering the maximum current draw of the motor(s) in the locomotive(s), any other electronics in the locomotive(s), e.g. sound, any smoke units, and any lamps or LED's in the locomotive(s) or cars.
The easiest was to do this is to set up your entire train and run it temporarily without the PSX1 or Airpax breaker in place. Let it warm up and measure the current it draws, via a Volt-Ohmmeter or a dedicate ammeter installed between the transformer connection going to the center rail, and the center rail. Remember that your curves, and any grades you have, will affect max current so you might want to make your measurement when your train is passing over them.
The last step is to install the PSX1 or Airpax breaker in place of your ammeter.
What value Airpax do you buy? One "slightly higher" than the your max current measurement.
This is not an issue with the PSX1. It's adjustable, so you set it to trip "slightly higher" than your max current measurement.
Define slightly higher? This is easy with the PSX1. Take a guess on the low side and run the train. If it trips too much for your taste adjust it upward slightly and try again. Repeat if necessary. Note: Be sure that you use a known good train on known good tracks. If the train has short-circuit problems inside it, or between it and the track, then the PSX1 should be tripping at lower currents so that the electronics inside the train don't overheat and fry because of excessive current draw from the short circuit.
Easy? Definitely not the simplest thing to do. Do you have an alternative? Yes, put PTC's (little self-resetting solid-state circuit breakers) inside each locomotive and each car having lights, smoke, StationSounds, etc. within it. @gunrunnerjohn has mentioned many times over recent years why this is the best solution, and that all equipment should come from the factory with these already inside. I agree. Why isn't it already done? We're back to money again -- it costs a little more to do so.
Good luck. In spite of being a relative newbie you can do it.
Mike
@Hp289 posted:
Possible?
Is there any advantage to doing this vs. putting one TVS at the power source, terminal strip, or lockon?
One has to be careful with how many TVS diodes are across any individual track if you run any DCS locomotives. Each TVS adds significant capacitance across the power that can and will degrade the DCS track signal. If you have half a dozen across the track, it's a significant factor.
If you're really worried about the effectiveness of the TVS, put one in each locomotive, the absolutely best place for EMI protection is right before the protected electronics.
@Mellow Hudson Mike well said! The only question I have at this point is if @Hp289 has a ZW-L, wouldn't it's (and the PH bricks') internal breakers be comparable to (or better than) the Airpax breakers, essentially making the Airpax unnecessarily redundant? In my opinion Airpax are a good inexpensive choice for postwar transformers.
Steve,
They should all be. But I haven't heard anyone confirm it, at least not yet, for the ZW-L (since it doesn't use the external bricks, i.e. PH-180's). If it's current monitoring circuitry is equivalent to the circuitry inside PH180's then you're absolutely correct. In that case there is no need for either PSX1 or Airpax.
Mike
The ZW-L has been brought up more and more recently in these breaker threads. I feel like we tend to beat around the bush on the ZW-L, myself included. The ZW-L has the same technology all new Power Masters, CW-80, and GW-180 use. When the excessive current is detected it folds back the voltage to give you time to fix it or prevent more damage if the short isn’t fixed or if it’s still a very large current draw it immediately shuts off power. It also has 12A (I think that’s what they are) breakers. I have had zero issues with my ZW-L and can’t ever remember a time when I tripped the separate breakers before the electronics shut off power.
you can also get information from the horses mouth (Mike Ragon)
With my new train room it's all new 20 amp breakers. I have a ZW-275 which I like better each time I use it. To keep from melting things I bought Lionel #91 breakers from "back in the day" that I think were made for it. I found 5 of them. I also have a 1033 that I do not use to much yet. The breakers are adjustable. I just crank them up and then run a train and then crank it down until it trips then back it off 1/4 to 1/2 turn until it runs. Derailments pop them immediately and I am far more confident than I was before. I had melted wire twice before this. And fried a loco that I have a new board for. It's good as it lets me vary the cutoff amps since the trains vary in what they draw depending on the engine and what the other cars pull.
Frank
@zhubl posted:The ZW-L has been brought up more and more recently in these breaker threads. I feel like we tend to beat around the bush on the ZW-L, myself included. The ZW-L has the same technology all new Power Masters, CW-80, and GW-180 use. When the excessive current is detected it folds back the voltage to give you time to fix it or prevent more damage if the short isn’t fixed or if it’s still a very large current draw it immediately shuts off power. It also has 12A (I think that’s what they are) breakers. I have had zero issues with my ZW-L and can’t ever remember a time when I tripped the separate breakers before the electronics shut off power.
@ftauss posted:With my new train room it's all new 20 amp breakers. I have a ZW-275 which I like better each time I use it. To keep from melting things I bought Lionel #91 breakers from "back in the day" that I think were made for it. I found 5 of them. I also have a 1033 that I do not use to much yet. The breakers are adjustable. I just crank them up and then run a train and then crank it down until it trips then back it off 1/4 to 1/2 turn until it runs. Derailments pop them immediately and I am far more confident than I was before. I had melted wire twice before this. And fried a loco that I have a new board for. It's good as it lets me vary the cutoff amps since the trains vary in what they draw depending on the engine and what the other cars pull.
Frank
Excellent. These last two posts wrap things up on this topic nicely, at least on the current (amps) side.
@zhubl has indicated that the ZW-L does indeed behave like a PH-180 alone. Its current sensing and control functions are the same and so the ZW-L alone will do the job. No need for a PSX1 or Airpax breaker downstream. No settings for "slightly higher than the your max current measurement" needed because the ZW-L is smart enough to handle the current draws presented by different trains without adjustment. Thank you Zachariah for your comments, and for the link to Mike Reagan's video to illustrate.
Last but not least, @ftauss has brought us an all-old-school method for a current monitoring and control method that uses classic Lionel #91 adjustable breakers. You still need to set them at "slightly higher than the your max current measurement", and he's mentioned a good way to do that, one that works for him. Thank you Frank.
Here's what a #91 looks like:
@Hp289, let's hope that this is now clear, and that you can proceed using what we've provided.
Good Luck, and let us know how it turns out.
Mke
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While there are layouts with trains that require 20 amp breakers on the track, personally I feel that is too high for the ordinary layout. A postwar ZW, for example, should not be breakers for more than 10 amps. If you use 20 amp breakers and have a power supply that can produce that amperage, you may well have hookup wire overheating.
There will never be more than 10 amps on any power district on my RR.
Sorry guys, swamped at the office today. Ok, so you've convinced me I don't need anything extra after my ZW-L as it goes out to the bus wire. That's settled. Is the #91 mentioned above meant to be that breaker, or is it meant to fill in for the TVS? I'm still a little weak on that part of it. Where to put those? I'm not going to put them in the engines. Is there a reasonable solution that goes with my planned construction method. thx.
I don't think you need any surge suppression or extra breakers at all. I would also suggest that if you have no plans to use DCS the TVS diodes sprinkled around aren't really doing much. A DCS TIU has a TVS on each of the 4 outputs that interface to the track, these are between the track and the electronics inside the TIU.
As GRJ stated, TVS diodes are meant to protect sensitive electronics and the best place for them is right at the board being protected. If a spike comes down the line the diodes short the excess to ground so they don't travel into the electronics. That is why there is a recommendation to install one in the engine.
Sprinkling a few TVSs around the track may give some protection. But if you think about an engine sitting on the track between diodes that engine will be subject to any spikes between the diodes. So are they really helping?
That's my opinion, subject to slunk jeep. 
"But if you think about an engine sitting on the track between diodes that engine will be subject to any spikes between the diodes. So are they really helping?"
Well they are limiting the voltage excursion across the track to some extent.
Multiple TVS diodes will probably work better than one, the downside being they're also stomping on the DCS signal. If you never plan on running DCS, no harm, no foul.
@Mellow Hudson Mike posted:Excellent. These last two posts wrap things up on this topic nicely, at least on the current (amps) side.
@zhubl has indicated that the ZW-L does indeed behave like a PH-180 alone. Its current sensing and control functions are the same and so the ZW-L alone will do the job. No need for a PSX1 or Airpax breaker downstream. No settings for "slightly higher than the your max current measurement" needed because the ZW-L is smart enough to handle the current draws presented by different trains without adjustment. Thank you Zachariah for your comments, and for the link to Mike Reagan's video to illustrate.
Last but not least, @ftauss has brought us an all-old-school method for a current monitoring and control method that uses classic Lionel #91 adjustable breakers. You still need to set them at "slightly higher than the your max current measurement", and he's mentioned a good way to do that, one that works for him. Thank you Frank.
Here's what a #91 looks like:
@Hp289, let's hope that this is now clear, and that you can proceed using what we've provided.
Good Luck, and let us know how it turns out.
Mke
Thanks Mellow Hudson Mike.
I should point out a couple of things. I'm using the TVSs recommended by GRJ. And even though I have Proto 2 and 3 engines, 2 Legacy engines and a half dozen LC/LC+/LC2/LC2+ I am only running conventional right now. Modern, MPC and postwar.
Frank
@zhubl posted:I have had zero issues with my ZW-L and can’t ever remember a time when I tripped the separate breakers before the electronics shut off power.
Ditto! Exactly, my experience with my ZW-L.
My switch machines and accessories run off the ZW (not the ZW-L) where I've added 5amp breakers & TVS's.
Thanks Gents, I'm going to skip the breakers by the ZW, and just find a way to use some TVS near the track.
