Quick question for folks here.

Our club right now uses PH180s everywhere for power (like 12 of them), and we're very happy with them, but we want more current, 4-5 locomotives in lashup is going to become a thing shortly (Christmas was good to me).... our layout is getting to the point where we can't really break it up into more blocks, it's already 20 independent blocks for DCS (5 TIUs X 4 ports each), and we don't want to use Z-transformers because we don't like how they each need to be independently reset when the power goes on. Also PH180s have less harmonics coming out since they are a pure magnetic without a chopper, which has advantages.

Does anyone know if multiple PH180s can be stacked in parallel? or has anyone done this? My initial thoughts are ...  you need to wire them phase matched (obviously) but even still there will be some *presumably but not necessarily small current* circulating between the two transformers because their output voltages and output resistances won't be *perfectly* matched. That may be small. I don't have a sense of the variation from PH180 to PH180. Also the mismatches means the load wouldn't be balanced between both PH180s and one would be favored (again by output resistance variation). Finally if one is switched on and one is switched off that would probably cause problems since the off ones secondary is energized and being a step up to produce an unexpected 110V.

Or is there any other fixed source that's bigger than 180W (short of winding our own transformer)?

Last edited by Adrian!
Original Post

I don't know if this is exactly what your referring to but I used 2 PH180s in parallel with a TPC400 with no apparent problems.  Small layout but I did have Legacy and DCS running on it.  

Last edited by Rich Melvin

Well, the TPC 400 handled the parallel connection and output the 20amps. The Legacy Powermaster 360 of today is its replacement.

I am surprised that more forum members haven't chimed in - there are a few more forum members that operated dual motor Pul-Mor ABBA power sets with incandescent lighted cars using two PH-180's.

Another variation that could creep into the equation is that the "new " production run from perhaps 2015 forward is different internally, at least with respect to the breaker, maybe more. A mystery story as to why it happened, but it did.  I believe that they can be identified externally by part number markings. (not positive on this)

Are you sure you want to do this? This is entering welding territory when a short occurs - no more sparks

Carl

Arctic Railroad

Adrian, on my last layout I ran MU's of 5 to 6 engines pulling up to 70 coal hoppers at times with all smoke units on. I needed two Z1000's in parallel on all 4 TIU channels (4 blocks @ 28 feet each), for 200 watts per channel. One brick per channel couldn't handle a train that size. The breakers would kick for no reason other then over current draw. When I started paralleling bricks together, it was easy to find if one brick was out of phase with the other, it simply pops one of the breaker's when you tie them together and power up. I also found that when two bricks are in parallel, both breakers would never kick together, when there was a derailment. Instead, the fuse in the TIU would blow. So I installed automotive (14 gauge) inline blade fuse holders on the TIU's input side. They come with a red LED that lights up when the fuse is blown which is a great feature. I started with 10 amp fuses but they couldn't handle a train that size. So I had to move up to 15 amp. I also had TVS's mounted on each MTH lock-on which would get very hot (but that may be normal for them). I have PSX breakers but never hooked them up. If I remember correctly it was because they could only handle 10 amps. I'm not sure on that though. That set up of 200 watts per channel was plenty and worked great until I dismantled the layout to move. Two 180's may be over kill. Wouldn't that give you 360 watts per channel? I would think 180 watts should handle the job. One thing I would like to do when I build my next layout would be to add an electric eye to each of the blade fuse holders, that would see the LED light up then throw a switch that would kill power to all the bricks. It sucks when one block dies and all the others stay alive when your running MU's and a long train.

Fuse Holder

Dave Z

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Last edited by Dave Zucal

I would think he's talking about running with passive wiring to the TIU with 2 PH 180s to a block?

I wouldn't put a 20 amp capability into a TIU channel. Maybe I'm not understanding this correctly?

It was stated that 10 amps is the limit to a single TIU channel? (15 maybe but 20? )

So the OP question is strictly how do they react tied in parallel?

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

I'll present an opposing view.  Yes, it's quite possible to stack the PH180's without damaging the transformers.  And yes, Lionel even makes custom cables to do so with the TPC and the PM360.  However, I did notice the circuit breakers weren't as effective when they were paralleled.  For whatever reason, we had several derailments that cooked wheels and internal wiring without tripping the breakers.

If you're going to do this, I recommend adding a follow-on high quality circuit breaker, perhaps invest in the PSX-AC modules to protect the downstream equipment.

Your probably correct Joe, that they run Passive. I would still fuse them after their stacked together and not trust that the breakers will pop simultaneously. For some reason when I had derailments, before I fuse the stack, only one would pop and the other would continue to feed current causing the wire to the tracks to get hot. Something prevents that second breaker from kicking. 

Dave Z

Dave, from the PSX-AC product page.

Range of Current Trip Setting The currents can be adjusted over a range of 4.8 to 17.8 amps. Values can be set using jumpers.

Engineer-Joe posted:

It was stated that 10 amps is the limit to a single TIU channel? (15 maybe but 20? )

 The rating is 10 amps.  Clearly, 20 isn't a good idea!

Last edited by gunrunnerjohn

You guys know all this stuff. Dave I believe you were running around 12 amps (+ ) total with the 2 Z1000 bricks in parallel?

Posting publicly that you can combine bricks, may lead to some users trying it that maybe don't understand fully the issues. They may not be getting full power to their track for various reasons. So they would attempt to overcome this by cranking up the incoming amps. That may lead to more issues like frying things that are not up to handling the current.

 For other readers who come across this post, I feel it is important to state the facts like only 10 amps max per TIU channel when wired normally.

Otherwise run in passive wiring mode. That keeps the TIU channels safe from the higher current.

Sorry for the interruption!

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

After looking at it in drawing form I think the grown up way is to have a psx-ac on each brick then do the power combining after. That way the current limit of the psx-ac doesn’t come into it and we can expand to as much current as wanted.....

Cool video. Other than the dramatic effect of running six powered units with smoke, you've put a lot of money at risk. Unless those are diecast hoppers, two powered units could have easily handled that consist. 

Just my $0.02.

Last edited by Gilly@N&W

Thank you for starting this posting Adrian. I have been know to test the limits so to speak.  So far Nine powered and 200 feet of train is my best. Nothing like a large consist, 30mph running at full RPM up a grade. 

Adrian! posted:

After looking at it in drawing form I think the grown up way is to have a psx-ac on each brick then do the power combining after. That way the current limit of the psx-ac doesn’t come into it and we can expand to as much current as wanted.....

I'd actually ask the question about how the PSX-AC handles being paralleled with another, that could be an interesting interaction.

Wouldn't you have all PH connected in parallel with the PSCs going to electrically isolated blocks of track.  That way a short would only affect operations in one block or train.

Jan

Here is how I am wiring my layout's two mainlines using two PH180 connected to one 360 PowerMaster with the TIU in passive mode.  On my test layout I was using only one PH180 to the track and was popping the PH180's CB with my Lionel Legacy E7 ABA (all powered with sound in both As) and 8 K-Line 21" passenger cars with Streamlighting.  Yes I can lower the amperage by going to LEDs but this was easier.  I did this setup (without choke or capacitor) with the PSX set at 15.4 amps and I had no issues.  The choke was added after I read about possible interference between the PSX and the DCS signal, and the DCS signal did increased from 8 to 9.  While the mainline is blocked per DCS best practices, each mainline is its own power district.  This may change when I start (if ever) stage 2 of the layout which more than doubles the trackage. 

Final_Pwr_Setup

Ron

 

TCA, TTOS, NCT, LCCA, PRRT&HS

 

Volunteers don't get paid, not because they are worthless, but because they are priceless!  Author Sherry Anderson

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gunrunnerjohn posted:
Adrian! posted:

After looking at it in drawing form I think the grown up way is to have a psx-ac on each brick then do the power combining after. That way the current limit of the psx-ac doesn’t come into it and we can expand to as much current as wanted.....

I'd actually ask the question about how the PSX-AC handles being paralleled with another, that could be an interesting interaction.

Hi All,

Okay I finally have an satisfactory answer to this (I was wondering about it too). We added a lot of connections exactly like the one in this drawing throughout our club layout to get more current. We did some with 2 branches and some with 3 branches but the result is the same...

brick_stack

It works well, but not perfectly. The PSX-ACs do not go crazy or anything, but small mismatches in the PSX-AC do imbalance the draw on each PH180. For example if you draw 10 amps from the above, you would expect each PH180 to give equal current (like 5A and 5A) but in reality because of small mismatches you'll find it's more like (6A and 4A). When you get to triple stacking it gets more diverse (we saw 5A, 3A, and 2A on a 3 branch system). So yes you can do this to get more current, but it doesn't get you to "n-times" the capacity of one brick because one PSX-AC will trip before the others as the current isn't drawn equally. Once the first PSX-AC trips the load jumps up on the remaining ones so they trip. You can see this on the oscilloscope but it all happens so fast in realtime it just feels like 1 circuit interrupter acting together.

We bought 7 new PH180 bricks and 7 new PSX-ACs, and we ended up trying different combinations on the bench to see which combo of parts minimized mismatch. In the worst case we saw like 3A and 7A, while we got it as good at 5.5A and 4.5A with some swapping. So if done right you can get like 17A capacity out of 2 of these in parallel (ideally 20A). On the 3 branch one it got us more like 24A than 30A, so I suspect as we get to larger and larger numbers of parallel paths, it's diminishing returns.

Anyways hope this is useful info for others!

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