How can I add circuit breakers to my old KW and ZW transformers (to safely run TMCC power)?
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The best for protection...
I've been using TVS diodes and 10 amp, fast blow, automotive ATC fuses with my Postwar ZW powering both TMCC and DCS. Works great. Otherwise the PSX breakers have good reviews as well.
IGGY,
Like Chuck I use the PSX-AC for all my circuit protection as well as having TVSs installed. Not only is it an excellent electronic circuit breaker, but it performs several other functions such as an alarm and LEDs let you know of a short, manual or automatic reset, track power on, plus others. However, this makes the PSX a bit expensive.
For a less expensive full protection option, LOU1985's setup works well but you have to replace the fuse every time you have a short. Some folks use other types of circuit breakers but if you want the best protection using a fast blow fuse (or a PSX) is best.
Here is a simple diagram using the TMCC handheld for command and the ZW's handles for conventional.
The TVS actually provides better protection for your engine's electronics than a CB or fuse. Many on the forum say only one TVS, at the transformer, is needed. Since a TVS can fail without you knowing it, I like multiple TVSs as backup, one at the transformer and one at each track connection. There is some thought that placing the TVS as close to the engine as possible is better, and actually inside the engine is best. TVSs are cheap so get a bunch.
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Everything you wanted to know (and more) about TVS diodes:
https://ogrforum.ogaugerr.com/...uts-thoughts-on-this
PSX-AC all the baby. Been using them for ten plus years now without a problem. And like the guys above some TVS for spikes and you're good to go.
Does anyone know the make and model no. for the 10 amp breaker used in the Lionel PoHo by chance? These seem to work really well and would be way less than a PSX-AC.
Rod
What photo?
Heck, ... body?
For the tmcc signal?
Rod Stewart posted:Does anyone know the make and model no. for the 10 amp breaker used in the Lionel PoHo by chance? These seem to work really well and would be way less than a PSX-AC.
Rod
Do you mean to use the circuit breaker part from inside a PH as an add on to your ZW or other transformer? I doubt that it would be cheaper as a part. Also, seems that Lionel does not have parts available for the PH except the cord.
cjack posted:Rod Stewart posted:Does anyone know the make and model no. for the 10 amp breaker used in the Lionel PoHo by chance? These seem to work really well and would be way less than a PSX-AC.
Rod
Do you mean to use the circuit breaker part from inside a PH as an add on to your ZW or other transformer? I doubt that it would be cheaper as a part. Also, seems that Lionel does not have parts available for the PH except the cord.
I don't think he is looking for the Lionel Part Number as much as the OEM Supplier part number which would be potentially reasonably expected to obtainable for under $5-$15 each through Mouser, Digikey, or similar.
Upgrade the circuit breakers inside your transformers to new solid state devices. That will protect your transformers properly, but not the trains. Most OEM CBs I've run across in postwar ZWs are way out of calibration and don't protect anything.
For protection of your engines, I'm with the guys above: Get the PSX-AC. It is considerably faster acting than what is in the transformer and can adequately protect your engine against short circuits.
As Ron and others have recommended, add TVS devices to your transformer outputs. These will protect your delicate electronics from harmful voltage spikes. HIGHLY recommended that you have these installed!!! Do note that if you are running with a DCS TIU, the TIU has internal TVSs on each channel. But multiple TVSs will not hurt. BTW, if your accessories have electronics, be sure to add TVSs to those circuits as well.
Chris
LVHR
Thanks Chris. Would I need a PSX AC for each track circuit? (ie.,4 for my ZW) I have already purchased the simple CBs Mr. Barret used for the CB box in his video.
How does the Lionel 6-34120 Direct Lockon compare to the PSX-AC?
You need one PSX-AC per circuit.
I have no experience with the Lionel 6-34120. Sorry.
Chris
LVHR
Don't the PSX-ACs only work with command? I seem to remember someone saying that they don't work well in conventional.
No. The environment is not a restriction. Will work either way.
Chris
LVHR
Trainlover9943 posted:Don't the PSX-ACs only work with command? I seem to remember someone saying that they don't work well in conventional.
They require a minimum voltage to operate. 18 vac in TMCC is fine, but low voltages like when running conventional may be too low. The low voltage limit is about 10 volts.
I just looked at the online manual for PSX-AC series CBs. There is no mention of a minimum voltage requirement. I've used them in a conventional environment w/o issue. Chuck, your link points to the DCC version, which is different.
Also, there are versions available which support multiple circuits. More expensive, of course, but may be cheaper than buying multiple single circuit units.
One can always contact American Hobby Distributors (800-671-0641) and ask them.
Chris
LVHR
While many modern component systems are "light speeds" faster than a thermal breaker or fuse and are a great idea as a SUPPLIMENT, I wouldn't trust any without a thermal fuse/breaker somewhere as backup. Add one, but don't simply replace thermals outright.
Too many variables that could go wrong. Shorts, to components forgetting their jobs short term, and lots of toasty power boards. Combined, the two should make a nice team.
(yes, many can "forget" and appear bad for one power up, then recall their job the next day at power up and continue working for a decade or more without issue. I didn't design them or anything, just noted the failures I didn't like 
)
