@gunrunnerjohn posted:The "dead" Powerhouse, if it's the new version that just shipped in the last couple of years, has a connector interlock that needs to be triggered in order to provide power to the output connector!
Do you know the details of this interlock? Can the PH-to-TIU adapter cable (DIY or aftermarket) that has made the rounds on OGR be modified to work with the NEW version of the PowerHouse?
Stan, you just need a pin in the unused location of the connector shown, and it'll depress the switch that is built into the PH180 output cord.
Interesting. If it's just a mechanical thing...and since I'd think it unsual for the average guy to have one (1) spare molex contact lying around...surely there's been a discussion on how to use some common household item (toothpick, whatever)?! 
There was a discussion about jamming things in the connector here, I'm sure a search may turn it up.
@gunrunnerjohn posted:You do realize that the new Powerhouse 180 requires a 3rd pin in the connector to enable power, right? Are you sure you just aren't missing a simple interlock?
I can't imagine any failure of the PH180 that could damage your TIU. The maximum voltage it can possibly put out is 18 volts as that's the highest voltage internally in the PH180.
Gunrunner,
The 3rd pin in the molex connector is not an issue here. Although the extra pin is no longer shipped with the 180 watt powerhouse, I did obtain them from Lionel Customer Service. They are installed in my Lionel TMCC cable sets (6-14194) which connect my powerhouses to my TIU.
I determined that my questionable powerhouse is dead by the following process:
1. I unplugged my working powerhouse and pinned TMCC cable from the fixed voltage 1 channel of my TIU. My meter read 18 volts at the spade lug end of the TMCC cable.
2. I then moved the same pinned TMCC cable to my questionable powerhouse and found no voltage with my meter.
Whether or not my powerhouse caused the failure in my TIU, this powerhouse appears to be defective right out of the box.
Although I don’t know exactly what caused my TIU failure, I’m thinking that my next steps are to get the powerhouse replaced under warranty and my TIU tested and repaired by an experienced MTH service station. Does this make sense to you?
Sounds like a reasonable plan. If you have the safety switch activated and the PH180 isn't putting out power, it's broken I suspect. OTOH, I still can't see how it by itself damaged the TIU.
I have never opened a Powerhouse, GRJ, but is it possible that insulation failures caused primary & ground to touch?
It would amaze me if the redesigned PH180 had such a basic flaw and still passed UL certification.
Doesn't UL just approve the design, but has no control over the workmanship of a Chinese plant?
This is a total WAG, but I’d bet the circuit breaker failed to open, overheated and failed to open circuit. If the breaker in the PH180 was defective from the start, a dead short could have allowed a lot of current to flow through that channel of the TIU. The TVS diodes do have a maximum forward current. A household 20 amp circuit could supply well over 100 amps for short durations until conductor heating raised the resistance.
You're forgetting the 20A fast blowing fuse in the TIU. 
But what's nothing less than confusing is on the TIU's I've seen, the four 20A fuses are in the common (black terminal) path of each input TIU channel. And since the overwhelming majority (if not ALL) layouts have a shared/common AC "black" terminal, the common current could flow thru ANY of the 4 TIU "black" terminals depending on wiring integrity. So, in a strictly pedagogical example, in the OP's situation of 2 TIU channels, you could have 39.9 Amps of return current evenly split between the two 20 Amp fuses... and therefore NOT blowing either TIU fuse! Remember we are just talking here! 
@stan2004 posted:But what's nothing less than confusing is on the TIU's I've seen, the four 20A fuses are in the common (black terminal) path of each input TIU channel. And since the overwhelming majority (if not ALL) layouts have a shared/common AC "black" terminal, the common current could flow thru ANY of the 4 TIU "black" terminals depending on wiring integrity. So, in a strictly pedagogical example, in the OP's situation of 2 TIU channels, you could have 39.9 Amps of return current evenly split between the two 20 Amp fuses... and therefore NOT blowing either TIU fuse! Remember we are just talking here!
Oh wow, I didn’t know that. I know in home wiring fused neutrals are a big no-no.
Another point is the fuse in the transformer windings, I suspect that's still there for the new Powerhouse. I know the older model Powerhouse couldn't conduct 100 amps for more than a millisecond or two, the traces on the PCB would be history if the internal fuse in the windings didn't go. I'm just not seeing the PH180 caused a TIU issue, that seems to be a longshot.
@gunrunnerjohn posted:Sounds like a reasonable plan. If you have the safety switch activated and the PH180 isn't putting out power, it's broken I suspect. OTOH, I still can't see how it by itself damaged the TIU.
GRJ, are you available to check out and repair my TIU? If so, how do I proceed? Thanks!
Peter
01. I occasionally look in on discussions on train devices plugged into the 120v house system, mainly from a concern for safety. Most here will know that only transformers plugged into wall sockets (et cetera) generally will have a UL label (both ZWs do not have one). Certain requirements go with this or comparable label; I believe the toy transformer standard is maintained by the UL organization, which now means it is open to review every 3rd year. Compliance with UL requirements will vary with jurisdiction involved.
02. It is probably not well know here that the concept of the first "brick"--the Lionel 135-watt version-- was based on implementation of a fundimental change to the toy train transformer standard. The requirement, that toy transformers have a circuit breaker capable of interrupting any current the particular transformer was capable of delivering under any connection arrangement, was dropped without comment.
03. I knew this meant that a system of "cascaded" protection was in place (this means the various protections were located in a series of different devices, from upstream to downstream. I opened my 135w brick, and determined it did not contain heavy short protection. There was one supervised set of contacts. Two failure modes would fit two particularly clear posts here at that time 20+ years ago: contacts burned open, or contacts welded closed.
04. I recognized that the TIU did not have heavy short protection, and recommended that it needed protection for itself. I believe I was the first to recommend this, despite not actually having one. (I'll note here that automotive fuses of the type fitted are not "fast" fuses --the fuse elements are flat, which radiate heat faster, making them slower.)
05. I recommend that if a TUI must be powered from a Lionel "brick", the brick cord should not be altered but simply attached to the proper sized "lineside shack" containing a supervised contact (3rd rail wire) with wire attachment devices in the later versions. This will avoid heavy shork damage to the brick; possible damage to the TUI may depend on the version.
06. Heavy shorts are difficult to create, but i do recommend breaking any habit of checking breaker operation by shorting the 3rd rail to an outer rail using pliers or screwdriver. At a minimum, calibration in the breaker system may be altered over time.
07. IMHO, I think the 180w brick is toast, altho the situation posts are not totally clear.
08. GRJ, I have an opinion on power loss in DCS signal loss. Power is adequate up to several football field lengths (was it 3?). Signal distortion was the problem above 135 feet of track on the MTH test track (in northern D.C.). Lacking a carrier wave, roadbed materials show a capacitance variation in the roadbed materials with the range of frequencies found in the signal. The 175' yard lead lost signal at its far end and being the 20th and last possible block (due more elaborate engine signups requiring a separate block, taken out of the yard lead), it could not be corrected. I eventually realized that the light bulb trick 40' out on the yard lead would have corrected this problem. Bulb data follows. It gives nanohenrys, in somewhat the same range as nanofarads for the capacitance variation. I've lost all but the bulb itself. The farads have a divisor of 2pi, IIRC, for you calculators. Test track Gargraves, wood ties, one rail dead (used for signal circuit--not DCS signal.) Wood base had most cap variance, IIRC; thin crushed rock ballast at little more. The layout was in a space 45 feet square, with a corner about 15 x 22 devoted to TMCC engines; I think there was a provision to convert the main lines (mostly double track, some sidings) to TMCC, but cannot recall how wired---except dim memory it was all TMCC originally.
00. END --Frank
Hello Frank. Greetings from Fairfax Station. Haven't seen you post in awhile. I am having problems following the above post.
You use the term "heavy short." I assume you mean a sort where the limiting feature is the internal resistance of the transformer. Not sure why it makes a difference if the short is heavy or "light."
I have Powerhouse 180 on my layout, which has a very fast-acting resettable breaker. Are you saying that this can't protect the circuit from a heavy short?
With all due deference to Frank's opinion, I think the PH180 has an excellent circuit breaker, and I have no issues with relying on that protection on my layout. First off, the PCB traces on the breaker board in the PH180 will fry long before the transformer core. I also believe the the PH180 also has a fuse link in the primary windings as well for overload protection in the case of an internal circuit failure.
I don't have to create a short with pliers or a screwdriver, I can create them in normal operation often enough to cause a breaker trip. Also, given the design of at least the older PH180 breaker PCB, IMO there is no danger of changing it's calibration.
I have no idea what "lineside shack" Frank refers to is, but if it's the TMCC Direct Lockon, IMO that's a piece of junk. It also kills the DCS signal, so hopefully you aren't running MTH equipment if you use one. Finally, it's prone to false trips, I had a number of locomotives that would cause it to trip as they came past the attachment point on the track for no reason. I got rid of all my TMCC Lockons, and I'll never consider it again. It also automatically resets and keeps banging the power into the short, talk about a dumb way to handle it! The reason I like the PH180 is I get to decide when power is applied again to the track.
I was not aware that some transformers have fuses in the windings, and in the primary windings. Are these integral in the windings and not replaceable? Or separate in the circuit?I note that if in the primary, they really provide little protection on the layout.
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