TIU no power through fixed 2 after spark

acrking76 posted:

I was testing an engine on the track that fixed 2 is connected to (only power connected at the time except for aux on TIU) and the engine stopped and I heard what sounded like a spark coming not from the track but the TIU which was behind me, the track had lost power but the breaker on my Lionel Powerhouse 180 had not been tripped, the engine was not derailed and Fixed 2 has seemingly stopped working altogether, all other terminals work fine. I am not sure if the TIU has a breaker to reset or fuses.  

Obviously open to check fuses.  Happened to me once.  Hope it is that easy.

they have fuses there are 4 inside if I remember right .look at the yellow blocks I believe they are the fuses. take out and check with vom meter. you can usually look on the top and can see if the fuse is blown look at all four you should see the bad one if it is blown.

1. 

Looks like your TIU is open. Bryant is right, next step is to check the fuses. I shagged this off of the 'ol innerweb. The fuses are circled in the picture.

Thank you all very much, the fuse for Fixed 2 was blown, I am very glad it wasnt something much more serious 

acrking76 posted:

Thank you all very much, the fuse for Fixed 2 was blown, I am very glad it wasnt something much more serious 

That spark you saw probably fed down the TIU output and the fuse served its purpose and saved you from "Gunrunner John stuff" type of grief.  You were fortunate as I was.  Able to identify the problem and fix it yourself.  That is one of the great values in having great forum members helping each other with many years of diverse experience.

Bryant Dunivan 111417 posted:

acrking76 posted:

Thank you all very much, the fuse for Fixed 2 was blown, I am very glad it wasnt something much more serious 

That spark you saw probably fed down the TIU output and the fuse served its purpose and saved you from "Gunrunner John stuff" type of grief.  You were fortunate as I was.  Able to identify the problem and fix it yourself.  That is one of the great values in having great forum members helping each other with many years of diverse experience.

Do you know what could have caused this? The powerhouse 180s have breakers on them that trigger when a train derails, but I have never had the TIU do anything especially with the train not derailing at all

You might want to consider fast acting fuses between the track and the TIU.  Much cheaper than repairing the TIU.

Danr posted:

You might want to consider fast acting fuses between the track and the TIU.  Much cheaper than repairing the TIU.

You could have been fiddling with something and shorted the red and black output.  No telling.  Without protection like fuses, it would eventually have gone down to the transformer causing it to trip.  Just did not make it down that far as it had to cross the TIU fuse.

For what it is worth, consider it a fluke until it happens again.  The most it will cost you is a new TIU fuse.  Then you would have to dig if you take out another.

your actually lucky because sometime when there is a train on the track and you get a short or spark you damage or blow the train ps2 or 3 boards get damaged or totally blown !if you only had a tiu problem you really lucked out!

It's a bit odd that the fuse blew if you are powering the channel with the Lionel PH180.  That has a very fast and sensitive electronic circuit breaker, and it's unusual for a 20A fuse to beat that breaker.

One wonders if the TVS on that channel is about to cash in.

I would check out the breaker on that PH180 to make sure it works. 

Joe Allen posted:

I would check out the breaker on that PH180 to make sure it works. 

gunrunnerjohn posted:

It's a bit odd that the fuse blew if you are powering the channel with the Lionel PH180.  That has a very fast and sensitive electronic circuit breaker, and it's unusual for a 20A fuse to beat that breaker.

One wonders if the TVS on that channel is about to cash in.

I Just checked it and it tripped fine, I misspoke when I said it was a PH180 the one I have on the track that tripped is a lionel PH-1 135 watt power supply but I just tested it and the breaker tripped just like on my other PH180's

Mystery solved!  The PH135 uses and ordinary thermal breaker and they're pretty slow to react.  Those will easily blow the 20A fuse first on a direct short.  The PH135 and PH180 are totally different designs, I stick with the PH180 models as they're a much better choice.

gunrunnerjohn posted:

Mystery solved!  The PH135 uses and ordinary thermal breaker and they're pretty slow to react.  Those will easily blow the 20A fuse first on a direct short.  The PH135 and PH180 are totally different designs, I stick with the PH180 models as they're a much better choice.

ah, is there anything I can do to use my PH135 with the TIU without it blowing the 20A fuse?

Add a better circuit breaker or replace it with the PH180.

So UPDATE I have a new fuse in the fixed 2 slot (I took it off an older TIU that I had) and I also changed the power over to a PH180, and now when I turn the 180 on it immediately triggers the 180s breaker, even when I dont have any wires from fixed 2 going to track, I am not sure if this means that the fixed 2 port is now unusable, or if the fuse from the older TIU is incompatible. 

That almost surely means the TVS in that channel has shorted.  That may have been the original issue in the first place, but the breaker of the PH135 simply didn't trip in time to save the 20A fuse.

This is a fairly easily repaired problem.

gunrunnerjohn posted:

That almost surely means the TVS in that channel has shorted.  That may have been the original issue in the first place, but the breaker of the PH135 simply didn't trip in time to save the 20A fuse.

This is a fairly easily repaired problem.

is this something I can repair on my own? if so how would I go about doing this

Well, the part you need is: 1500W 33.3V TVS at Digikey.  It is possible to replace those without removing the board, but it's easier to remove the board at times.  Note that if you don't have decent soldering skills and tools, you could end up wrecking the board, that would make it an expensive repair.

gunrunnerjohn posted:

Well, the part you need is: 1500W 33.3V TVS at Digikey.  

Your link is to the 1.5KE39CA.  Can you explain the evolution of the preferred TIU TVS?  I was looking in some of my TIUs and they use the 1.5KE33CA as shown below:

I very strongly recommend that you install breakers on each TIU output, with ratings of no more than 10 amps.  (I use 7.5s and 5s, but don't use smoke)These will open before the 20-amp breaker inside the TIU.  Check the Blue Sea line of push button breakers at Defender Marine of West Marine.  They are well under $10/each.  Fuses are too expensive in the long run.

I even have them on the channels powered by a PH185 (which replaced a PW ZW), and the breakers haven't opped since I went to the PH180.  They pop quickly on derailments on channels powered by a Z4000 & a PW ZW

stan2004 posted:

gunrunnerjohn posted:

Well, the part you need is: 1500W 33.3V TVS at Digikey.  

Your link is to the 1.5KE39CA.  Can you explain the evolution of the preferred TIU TVS?  I was looking in some of my TIUs and they use the 1.5KE33CA as shown below:

I had a shorted TVS a while back..snipped one end to take the TVS out of circuit(for test purposes) and all was restored...installed a new one i had in stock. I use 7.5 amp fast blow fuses on each of my channels.

Yes, but how did you know exactly which part number to use?  I figure most guys have zero TVS "in stock".

Stan, the TIU can see voltages of 22 VAC, a peak voltage of 31.1 volts.  I figure maybe that's why the most TVS failures I see are in the TIU, so it makes sense to "bump it up" a little.

1.5KE33CA

1.5KE39CA

OK.  I like your logic.  Someone please tell me otherwise, but it seems that for years the recommended TVS for O-gauge layouts has been the 1.5KE33CA and the 1.5KE36CA (to wit, see the pinned Electrical Reference thread). 

For the cheapskates amongst us, member rtr12 turned me on to an Asian distributor which has the 33 and 36 TVS components for about a dime each - considerably less than DigiKey (and even less than what I could find on eBay) though you'll have to wait for shipping from Asia!  Their website can be a little difficult to maneuver if you don't know exactly what you're after, but truth be told even DigiKey can be overwhelming for a novice.

Don't forget that very shortly these gizmos will be subject to a tariff.  I have no idea how tariffs are levied on a direct sale from an Asian firm to a person here is US.

[Please do not kill this thread by going off on ranting about the wisdom or politics of tariffs.  It is what it is.]

stan2004 posted:

Yes, but how did you know exactly which part number to use?  I figure most guys have zero TVS "in stock".

I used the ones GRJ recommends...the 33ca's ..got a bunch from Digikey.

For 18V on the track, I'm sure any of the TVS parts mentioned would be suitable.  For the TIU's, since I've had a few in with shorted TVS parts, and a couple sitting in the "to be repaired" stack, I started upping the specification a bit to see if that helps.

May be splitting hairs here, but should the electrical reference info be updated to include the 1.5KE39CA?

If yes, I am gathering from this thread the higher rated TVS would be for those using a 19 to 22 volt (31.1 peak/max) power source like a Z-4000. The rest of us using 18 volts (PH-180s etc.) would still be ok with the TVS parts previously recommended (33 & 36)?

That's correct, if you're using 22-23 VAC on the TIU, it has no problem with it, but the TVS is marginal, at least in specification.  Since they do seem to die more often in the TIU than anywhere else I've seen, I figured maybe I'd just kick the spec a few volts and see if I keep getting them back.   Of course, I suspect the TIU is the place where most of them are, a vast majority of the operating public doesn't have any idea what a TVS is.

On the farm we've  always called them (TVS) transorbs.

I haven't heard that term in years.

Ok, sounds like a good idea. I'll try updating the info in the 'sticky' thread. Maybe I'll add something about not running Lionel stuff over 19v too, don't want anyone to think it's ok for the higher voltages with Lionel stuff. Lots of folks not knowing what a TVS is gave me the idea for the Lionel stuff.  I'll add a link to this thread if anyone wants more detail.  

I think the PXS-AC documentation refers to them as 'transorbs'. I wasn't sure exactly what that was when I first read their info several years ago.  

I butchered enhanced the info in the 'sticky' thread with the PTC and TVS info to include the 1.5KE39CA as being discussed here. If anyone has better wording to describe this, I'm all ears!