How big of transformer do I need?

The Z4000 is big. It is also great handling MTH trains. It makes even the first PS1 versions fun to run.

You could probably start with a Z1000. I just think you will end up wanting more. There are plenty of the Z4000s around, look for a deal.

You might consider a Lionel GW-180 set-up. It provides 10 amps of current @18VAC. I use one for  my test bench and also use a separate 180 watt "brick" to power my full "S" gauge empire without issues. This is an equivalent to the Postwar "KW" transformer, but is up to date electrically, has bell and horn/whistle buttons built-in and has a fast acting circuit breaker to boot.

I have the MRC Pure Power Dual and a MTH Z4000. My Z4000 is one of the first ones built (early 1998). It has been completely trouble free for almost 20 years.

I also like having volt and amp meters, which are on both.

When you start running engines with 2/4 motors, sound, smoke units and lighted passenger cars, it starts to add up.

Right now you don't NEED a Z4000.  However, using the normal learning curve and growth of NEEDS in a few years you will.  May as well buy the largest you can afford.

John in Lansing, ILL

I agree with all above regarding the 4000.  It costs a bit more more, but you will probably never need to upgrade after that.  It will push your trains you plan on running and have plenty of juice to run your accessories.  You won't need another transformer for accessories only. 

Gentlemen,

  Everybody needs a Z4K or a ZW-L, go for it!

PCRR/Dave

That is a great track plan.

   How big the layout is, wiring type, switches, accessories and locos/cars as a whole make that easier easier answer bettter.

Eg. I have PW locos that peak at over 5à under loaded starts, and newer switchers that can't pull 2a at stall. One layout uses track powered switches, another, constant power. I have post war whistles and like the voltage boost vs a slow down.

  You say you have no issues. so far. I'd see what happens as is.

  All the advice is good if you do have an issue.... But it likely won't be major league anyhow, more like an occasional pita.

  A simple solution (assuming you can with your  turnouts) is supply turnout coils a new power supply of their own, which could be pretty small as only one fires at a time; like maybe a big wall wart.

So that's what Dave has been up to at the new place...

For running trains, consider a Lionel Powerhouse 180, feeding several TIU inputs.  Price is low; breaker is fast.  I replaced one of my PW ZWs with one, and it's great feeding 2 channels.  I also use a Z4000 with receiver and another PW ZW

hrspla posted:

 I was using a 75 watt Mth brick and didn’t have any trouble   

You've pretty well answered your own question. No, you don't "have" to buy a larger transformer. At least for now. What I would recommend is buying an inexpensive voltmeter, and ammeter. That way you can see the work the transformer is doing.

The Z750 is good for ~4a @18VAC. On my layout, I have a separate brick on each TIU channel. If you're buying another transformer I would spend a few extra $$ and step up to the Z1000.

In any case, your decision to buy another transformer should be based upon the current draw of your consist, on your layout. Do not do it because of any pretty lights, advertising, or what everyone else is using.

Before our club added TIUs, I frequently ran my PS2 consists using the DCS RC w/ a Z1000 transformer. The layout at that time was about 20' x 32'. 

I have a couple of loops powered with the Z1000s and for most case, they work well.  I have tripped the breaker on one of my Z1000 when I have my GG1, E-6 ABA and 14 passenger cars (not LED equipped) when I have them both going more than 50 smph.  The breaker does not trip at 50 smph or slower so I have kept them on the Z1000.  Just note that the amps used increase with speed and/or increased number of engines or the use of smoke.  My loop with a Lionel Hesler, MTH Climax, Ps2 converted Lionel WM Shay, MTH Alleghany, and MTH PS4 Daylight with 5 passenger cars have not tripped the breaker at 15 smph.  I do not have enough hands nor to I dare run them faster because the Hesler runs at 27 speed steps, the Climax runs at 14, the Shay runs at 13, the Allegheny runs at 14, and the Daylight runs at 15 smph.   Enjoy running the with the Z1000 and upgrade to the Lionel 180 bricks (I have 3) and/or the Z4000 (I have 3 as well) once you exceed the capabilities of the Z1000.  You can always use them after you have upgraded to another power source.  Even the MRC Pure Power Dual (I have one), is a possibility and can be used without issues.

  I didn't get that photo last time on this page (wondered what Marty was talking about, figured he had visited)   

That is pretty nice. Needed at the moment or not, something about those vertical throttles DO sort of go hand & hand with something of that caliber, lol.. Trivial, but the truth.

  Sort of like that feel of PW that's so hard to explain, a vertical throttle in each hand adds a unique feel to running that has to be experienced to be understood.  I don't run one here anymore, but thats because of placement, available area, and how I sit/stand to run them. If I ever get the basement going again, it will get ZW, Z4k, Dual power, or even a VW for power again, just because of vertical throw.

I see from your profile you are in Kentucky. I am in Indiana. If you are interested, I have a friend that wants to sell his ZW-C w/volt/amp meter that has 4 180w bricks. I believe it is the celebration series, 6-22982; no box.  He wants $375 which I think is a good price. Let me know if interested and we could possibly meet to avoid any shipping costs.

With your layout size, I would look at going with at least a couple of 180w bricks to power each mainline.  The ZW and Z4000 transformers give you the ability to control voltage separate from using the TIU variable channels and the bricks alone.

Four 180W bricks are worth the $375, so the ZW-C is a free addition.

Seems to me that the test of whether a transformer is adequate, assuming that it has a properly functioning breaker, is whether the breaker opens during operation.  If a breaker doesn't open but train is running slowly, then either (1) the breaker isn't properly functioning or (2) the manufacturer didn't properly size breaker with respect to the gauge of the secondary wire (I wouldn't expect this with a UL-listed transformer), or (3) more likely, wiring between transformer and track is inadequate, either in wire gauge or in an inadequate number of drops to inner and outer rails, or both.  Use an AC voltmeter to check voltage under full load at the transformer terminals and again at the lockon or equivalent and again out on the layout where the loco is running.  All locations MUST be under full load.

I would add that when using an external breaker, it ought to be sized with regard to the load you will be using.  The reason is that wiring inside cars and locos is usually not adequately protected by the transformer breaker.

"Seems to me that the test of whether a transformer is adequate, assuming that it has a properly functioning breaker, is whether the breaker opens during operation. "

Seems to me that the scientific and foolproof way is to measure or count up the maximum amount of wattage your equipment uses, add 40% and buy a transformer that can deliver that much power.  I said deliver, not draw, BTW.

This forum receives messages quite often about electrical matters. It's always a good idea to avoid short circuit tests, spark tests, circuit breaker tests, and other activities that put your equipment at risk.  Nothing beats a $9.00 ammeter for a definitive answer.

 I like Arthur's post above about sizing equipment rather than just drawing stuff to it's max to see what happens. I have been guilty of that test myself. I ran 3 MTH G scale engines with the smoke on seeing if the Z1000 brick could handle it. It's rated at 6 amps? and the three should be at 5.5?? However I did not run it for long or expect it to do this regularly. The power dropped enough that I knew something was at it's limits. It did trip on three. I have to imagine it's how much current is available at the engine???

 So going 40% above the need sounds reasonable. I might ask if that includes peaks? These engines draw more with the smoke on and when pulling heavy trains I've noticed. So I would start figuring at, at least 2 amps per engine. Maybe 2.5?? (at 18volts) Add in extra for lighted cars too.

 I left AC and went to the recommended large DC packs outside anyways. They handle 30 amps total and can deliver higher volts to the track. That seems to lower the amp draws of these engines under loads. I try to run at 21 to 23 volts at the track, and optimally 21 to the engine. The MTH engines read out the voltage they see. I have run seven engines with smoke on and seen around 5 amps on the meters. That's G scale using 14 gauge wire in shorter lengths.

 I tried a test outside with a Z4000 to see any difference between AC and DC. It was during a bad time of power issues and it took me awhile to figure out my track joints had corroded. I need to try it again now that it's fixed.

 I used to run large sound systems and never wanted the amps to work too hard. Some guys swear that the system sounds better when the amps are really working. I have always believed that they have lost their hearing and that effected their judgement! I never want an amp to clip and take out my speakers. I never lost a single speaker in my career.

 So when I came to model trains, I went for bigger power.

RJR posted:

For running trains, consider a Lionel Powerhouse 180, feeding several TIU inputs.  Price is low; breaker is fast.  I replaced one of my PW ZWs with one, and it's great feeding 2 channels.  I also use a Z4000 with receiver and another PW ZW

after all my yakin' I should have went with this. I use 4 PH180 watt bricks on my O scale layout. You can buy them as you need to. I started with just one myself. I quickly added a second one though.

You need lots of power after all we have three rails to feed  

Arthur, how many model railroaders have the equipment to accurately calculate wattage being drawn on a 60Hz AC circuit?  I do agree not to use short circuit, etc, testing.

Joe, aggregate current available at locos equals current flowing out of the transformer.  Note you're guessing as to the 5.5.  I actually have a lot of power available on my layout---I don't skimp---and the largest "loop" has a 7.5 amp thermal breaker.  If the Z4000 ammeter is correct[?] I rarely draw over 5 amps running 3 locos on thay circuit, but if they are passenger trains, the breaker will pop.  Most of my O-gauge locos rarely puil over 2 amps (smoke off).

You don't need lab accuracy to know roughly what you're drawing, a plain $10 ammeter will do the trick.  This isn't rocket science, we're just running model trains.

RJR posted:

Arthur, how many model railroaders have the equipment to accurately calculate wattage being drawn on a 60Hz AC circuit?  I do agree not to use short circuit, etc, testing.

Joe, aggregate current available at locos equals current flowing out of the transformer.  Note you're guessing as to the 5.5.  I actually have a lot of power available on my layout---I don't skimp---and the largest "loop" has a 7.5 amp thermal breaker.  If the Z4000 ammeter is correct[?] I rarely draw over 5 amps running 3 locos on thay circuit, but if they are passenger trains, the breaker will pop.  Most of my O-gauge locos rarely puil over 2 amps (smoke off).

Yes it was a guess for the AC. It didn't trip the Z1000 right away. It did seem to take it near it's limits. Then the breaker went. That was running a large G scale train back when I ran with AC. I run different brands of trains that I convert to PS. They load down more when they pull a big train up large grades too!

Q:  Arthur, how many model railroaders have the equipment to accurately calculate wattage being drawn on a 60Hz AC circuit?  

A:  You don't need lab accuracy to know roughly what you're drawing, a plain $10 ammeter will do the trick.  This isn't rocket science, we're just running model trains.

Thank you, G R J