PSX-AC versus 5 or 8 Amp TE Connectivity Potter & Brumfield Relays W28 Series circuit breakers

Great question Kris!

i don't know the true answer. Over the years, I converted my power to Lionel PH 180's. They have such a fast breaker built in that I haven't looked at other breakers. That said, if I ran a ZW 250/275 I would buy the PSX-AC. the difference is that the ZW 250/275 can put more than 10 amps to the track, but it can't beat the PH 180 breaker. Wondering what others will say?

George 

The direct Lock-on is another option (6-34120), but is priced near the psx-ax.

Find an in-line fuse holder and 6-8 amp fastblow fuses. I think they are AGC, or the newer blade type may be easier to find.

using a TVS (Transient Voltage Supressor) is the real key. It will absorb spikes that can harm electronic boards, sometimes even before a fast electronic breaker trips. Sometimes there are voltage spikes for other reasons.

The house wiring is protected at the panel. The transformer is protected in the transformer. One needs something to protect the track and accessories.

The TMCC Direct Lockon stomps on the DCS signal, so that's not a good choice if you ever want to run MTH stuff.

If you have MTH DCS, you want good circuit protection before the TIU.  I'm another one that uses the Lionel PH180 bricks with their very fast electronic breaker.

I think the TVS and fast blow fuse would be good additions to your breaker. Also I believe some have suggested using a slightly smaller breaker than needed in hopes of a faster trip time, but I will defer to the experienced and knowledgeable on this one.

I don't use the W28 breakers on my trains, but I have some and they trip fairly quickly with a direct short. As the others have said, if you have a PH-180 for power you probably don't have anything to worry about, but adding a TVS might still be a worthwhile addition and they are pretty cheap at Digikey.

I use fast blow fuses here on some of the bench stuff I have for fiddling around with. So far, haven't had a smoke release with that stuff, fuse always went first.   It's the un-fused things I have to be more careful with... 

Radio Shack used to have (probably still do) a pretty inexpensive stationary fuse holder that you could screw to your bench or table, that's what I have on my fiddle stuff. The inline holders are fine too, maybe easier to find also.

While I love PSX-AC they have one drawback.  They don't work in the conventional world verywell.  That's not a problem on my layout as I'm all command but for you out there that still like your throttle time, the PSX-AC acts a little squirrely  below a certain voltage..

Just to add to the other part of your question - look at the time trip summary block in the graph  on page 1. You'll see that to get trip times near .2 seconds there has to be 200% or better of the rated current.

That's ok for conventional.

Hi and thanks for the replies.

The fog at the electronic woods has lifted and I can see that add the TVS to my future setup is the way to go. The current plan is PH 180 and 135 to the TIU and TVS at the track side.

Well, the PH135 doesn't have the excellent breaker that the PH180 has, so I would consider giving it a little help.

superwarp1 posted:

While I love PSX-AC they have one drawback.  They don't work in the conventional world verywell.  That's not a problem on my layout as I'm all command but for you out there that still like your throttle time, the PSX-AC acts a little squirrely  below a certain voltage..

I don't run conventional, I am also command only, just as you are. Had you not posted, I would probably have never known. Good thing to know though, just in case.

Moonman posted:

Just to add to the other part of your question - look at the time trip summary block in the graph  on page 1. You'll see that to get trip times near .2 seconds there has to be 200% or better of the rated current.

That's ok for conventional.

Exactly my thoughts on these (FWIW). And your post here is why the W28 breakers scared me away, especially since I am all command control. Good explanation here. 

Hi and Thanks for the replies.

Dear John

What would suggest for the "little help"?

Dear rtr12

That is why I ask, if you are not or do not know the answer ask on OGR.

Dear Carl

Now that scares me 200%, ouch there goes the board on the engine.

Old school  7.5 amp fuses installed on each track circuit.  Center top of this picture.  Fuses are standard automotive fuses, available at any parts store.  Fuse blocks are available from Grainger.

Accessory fuses  3amps or less.

Like Mike says, for the PH135, I'd consider something like fuses.  I'd probably for for higher value fuses, 10-12 amps, that will avoid nuisance blowing.  For a real short across a PH135, I can assure you that you'll peak at more than 10-12 amps as a rule unless there's considerable resistance in the path.

Dear John and Mike CT

Thanks for the information and the tips.

Now I have the PH 135 issue solve thanks to all of you folks.

Note that I have two (2) PH 135's paralleled. The arc and spark, track welding, when de-rails occurred, was impressive, until I added the individual track circuit fuses.  Parallel power supplies, lower left in picture.

Best wishes with your project.