What is a good estimate of the max amperage that would support most O gauge trains

I can get up to 10 or so amps with illuminated cars and multiple motors on a single train. Don't forget some power supplies can exceed 50 amps in the event of a derailment.

Depends.  If you have incandescent lighted passenger cars, figure from around .3 to .4 amps for each.  Probably the max any locomotive will pull would be something like the Vision Line Big Boy, that sucks up 4 amps with a light load and all the smoke features enabled. 

Thanks. For this project, we're probably concerned with the amount of amperage that the loco draws while pulling cars. (Not really with the amperage the lights take from the track).

I know some people (myself) just pull 10 or fewer cars - slight hills. I never exceed 2 amps.  But I imagine other people have more powerful locos and pull longer trains than I do.

3RaylFan posted:

I know some people (myself) just pull 10 or fewer cars - slight hills. I never exceed 2 amps.  But I imagine other people have more powerful locos and pull longer trains than I do.

Yep, some of us pull more cars.   This is with two Legacy U-Boats, one lead and one in the middle of the consist.

gunrunnerjohn posted:

3RaylFan posted:

I know some people (myself) just pull 10 or fewer cars - slight hills. I never exceed 2 amps.  But I imagine other people have more powerful locos and pull longer trains than I do.

Yep, some of us pull more cars.   This is with two Legacy U-Boats, one lead and one in the middle of the consist.

Is that the same train coming by again!? Glad there were no cars waiting at the grade crossing!

Yep, it went around around 50 feet of track and wrapped back around and comes up the other side.  The whole train was around 102 feet long.

"I can get up to 10 or so amps with illuminated cars and multiple motors on a single train. Don't forget some power supplies can exceed 50 amps in the event of a derailment."

Wow!  My house is wired w/ 20 A breakers for most wall socket receptacle circuits albeit at 110 VAC.

pgtr posted:

"I can get up to 10 or so amps with illuminated cars and multiple motors on a single train. Don't forget some power supplies can exceed 50 amps in the event of a derailment."

Wow!  My house is wired w/ 20 A breakers for most wall socket receptacle circuits albeit at 110 VAC.

Comparing household line AC AMPS to low voltage AC amps are orders of magnitude different due to ohms law: http://hyperphysics.phy-astr.g...electric/acohml.html

pgtr posted:

"I can get up to 10 or so amps with illuminated cars and multiple motors on a single train. Don't forget some power supplies can exceed 50 amps in the event of a derailment."

Wow!  My house is wired w/ 20 A breakers for most wall socket receptacle circuits albeit at 110 VAC.

Multiply the toy train "amps" by 2, then divide that number by 120.  You will get a rough estimate of the "household" current needed. 

Usually 1 amp of household current can supply at least 6 amps of toy train current.

You have to compare the wattage not the amps.

The largest SINGLE transformer I know of is 400 watts (Right of Way and no longer available.)  The largest transformer controller with multiple power bricks  is 720 watts.  That would be the ZW-C with four PH180 bricks.  So those are the numbers you need to think about if you're estimating house wiring for your train room.  Really you wouldn't need as much as a kitchen with electric cook top, microwave, toaster, blender, etc.

As far as power to the track: 10 amps at 20 volts (200 watts) is about the most you would want on one circuit.  That might be two or even four AC motors pulling a train of lighted cars.  If you have a derailment with more current than that, you'll be welding wheels to the track!

Ted S posted:

The largest SINGLE transformer I know of is 400 watts (Right of Way and no longer available.)  The largest transformer controller with multiple power bricks  is 720 watts.  That would be the ZW-C with four PH180 bricks.  So those are the numbers you need to think about if you're estimating house wiring for your train room.  Really you wouldn't need as much as a kitchen with electric cook top, microwave, toaster, blender, etc.

As far as power to the track: 10 amps at 20 volts (200 watts) is about the most you would want on one circuit.  That might be two or even four AC motors pulling a train of lighted cars.  If you have a derailment with more current than that, you'll be welding wheels to the track.

Validates what I have.  One of my channels on ZW-L pulls 8 amps and goes to 9 with trains running in Lionel Hobby Shop and MTH gas station.  I started using the other.  It’s around 4 right now and will finish around 8.  I have both led and incandescent.

As far as 3 x lighted car passenger sets on the other 2, they draw around 4-5 peak.  BTW at 14 VAC.

I hope this is typical and helps you visualize.  

I have been worrying about my MTH 4000 on my layout. Right now I am only using the one side of the transformer and I see I am pulling2-5 amps, but with a long passenger train and all the lights I noted much higher amperage. So if I can ask a couple of questions in this thread....I assume when I split the layout wiring to use both sides of the transformer, I will cut down on the amps, since I will be powering just one insulated loop separated by my Ross crossover  on each post?  What is the amperage rating for the Z4000 as I thought it has a breaker if it exceeds?  Thanks.

Ted S posted:

... largest transformer controller with multiple power bricks  is 720 watts.  That would be the ZW-C with four PH180 bricks...

760. The ZW-L is 720.

My personal opinion is if you need more than 10 amps on any power district, you need to reconsider how you're allocating the power, not add more power to the track.   YMMV

I do go 14 amps with long trains - dual motors - lighted alum. passenger cars with two PM-1s in parallel set to same TR#. 7 amps just isn't enough.

It really depends on what engine and it's load you are powering and what accessories you may also have hooked up.  3-4 amps is probably good for modern stuff, but you might just exceed that with some older Lionel pullmor powered F-3's or something similar on a long train.    I think I have probably gotten to 8-10 (have not measured it).  John is probably right though, if you have a situation that drives you up above 10 amps, might want to think about a redistribution.  Also do not forget to consider the gauge of wire you are using to your track and all your accessories.

I have a PW celebration series CP passenger set with ABBA (4 Pullmors) and many, many cars. It needs a good 12-14 amps. 

Rob mentioned combining 2 Powermasters in parallel. If that works, I wonder if I could splice two ZW-L outputs in single channel mode using a single TMCC ID?  Or is that perilous? I would be worried about back feeding one of the outputs and smoking some FET’s if I accidentally had the throttles set unevenly. Am I overthinking this?

I suggest you do NOT parallel electronic transformer outputs!  They duke it out and bad things can happen.  Doing that with the MTH Z-4000 will result in the transformer shutting down.  MTH also tells you not to do it, and it's for good reason.

You can parallel things like plain transformers as long as they're at the same voltage, or are contact voltage like bricks.  However, don't depend on reliable operation of the circuit breakers if you have them in parallel.

GregR posted:

Rob mentioned combining 2 Powermasters in parallel. If that works, I wonder if I could splice two ZW-L outputs in single channel mode using a single TMCC ID?

Yah, no don't do that.  I'm using identical bricks set up like the TPC two-brick configuration w/o the expense of a TPC 300/400 and w/o the need for a Command Base.

The PM-1 bricks don't mind the backfeed if it happens... in fact I used to have a switch to go from PM-1 control to transformer control and found it was superfluous, now I just put the PM-1 to zero and turn up the ZW(wired in parallel to the bricks).

gunrunnerjohn posted:

I suggest you do NOT parallel electronic transformer outputs!  They duke it out and bad things can happen.  Doing that with the MTH Z-4000 will result in the transformer shutting down.  MTH also tells you not to do it, and it's for good reason.

You can parallel things like plain transformers as long as they're at the same voltage, or are contact voltage like bricks.  However, don't depend on reliable operation of the circuit breakers if you have them in parallel.

Thanks. Just what I expected. Your point is well taken. 

Maybe a couple of 180W bricks plugged into a 360W Legacy Powermaster is a better, Lionel approved approach for higher current applications. That’s about 20A max?

Remember the old equation. Watts equals volts x amps.  If you are running a train

at say 18 volts you'd better watch out if you have a 200 watt transformer and you are

drawing 10-12 amps.

lewrail posted:

Remember the old equation. Watts equals volts x amps.  If you are running a train

at say 18 volts you'd better watch out if you have a 200 watt transformer and you are

drawing 10-12 amps.

Circuit breaker should trip if gets 12 or amps correct?

If this amperage rating is for just one engine only, Loksound makes DCC decoders they say are for use in O gauge engines. They are rated in the 3-4 amp range from what I have read. The Loksound website or a good Loksound dealer should have the actual specs for their O gauge DCC decoders. Assuming Loksound did their homework their specs should be a good estimate of one O gauge engine's amp draw.

I don't know if any other DCC companies have DCC decoders rated for O gauge, there may be others? Loksound is the only one I have seen so far, but I don't follow the DCC stuff all that closely. I've always been interested in DCC, but I don't have a DCC system. It's on the 'would like to try someday' list, but so are a lot of other things. 

Any O-gauge locomotive that has a motor drawing 3-4 amps has a problem!

Re: "However, don't depend on reliable operation of the circuit breakers if you have them in parallel."

My high power source (built before PowerHouses were produced) are 18V 20A Hammond transformers and TPCs.  This setup has pumped up to 15A running three trains on the same loop. I initially relied on the TPC's circuit breaker for protection.

For a self resetting circuit breaker, I tried MOVs following an Application Note that suggested paralleling the MOVs for higher amperage than the biggest MOV available.  The App Note said in an an over current condition, the most sensitive MOV would trip first and the remainder would cascade immediately.  I rigged up a box paralleling 4 3A MOVs and found that it did trip at about 10A.  (my test load was resistance heading coils).  The self resetting feature of the MOVs was inconsistent in the time to reset after the over current was removed so I didn't adopt this solution.

To improve short protection, I switched to magnetic circuit breakers to eliminate the lag of thermal breakers.

I repeated my high-power experiment using instant-trip magnetic breakers rated at 10A.  These breakers have a pull to reset button so I could run with either a single breaker or parallel two breakers.  Both breakers (solo) tripped reliably at 10A.  When I paralleled the breakers, the trip point was 15A - not the 20A I was expecting.  The 15A trip point was consistent.   Why the max current was 150% instead of 200% when the breakers were paralleled I don't know.

These days, I find the quick reaction and self-resetting over-current protection capabilities of the Lionel TMCC direct lockon and the PowerMaster are good solutions.  10A at 18V is sufficient power.

dogdoc posted:

lewrail posted:

Remember the old equation. Watts equals volts x amps.  If you are running a train

at say 18 volts you'd better watch out if you have a 200 watt transformer and you are

drawing 10-12 amps.

Circuit breaker should trip if gets 12 or amps correct?

Circuit Breakers in transformers, at least in old ones, are there to protect the transformer and will not protect your loco from over current should it draw more than it can handle.  Keep in mind a ZW for example cost more than many smallish sets back when they were sold and I expect it was also a UL requirement to have a circuit breaker to protect the "household".

gunrunnerjohn posted:

Any O-gauge locomotive that has a motor drawing 3-4 amps has a problem!

Are you saying 3-4 Amps is a high amperage draw for a motor on an O gauge loco?

Yep, if the motor is drawing 3 amps at 12 VDC, it's dissipating 36 watts.  That motor will be smokin' hot!

The Loksound O gauge decoders appear to have several more outputs than the smaller HO and N ones, lots more pins anyway. I took the decoder info above to mean total amperage for the engine, but maybe they were talking about just the motor? 

Amperage?  We haven't dealt with that since the 80's?

With trains today, I don't even look at that anymore. Running 7 MTH DCS Diesels at once, it might get to under 3 amps each with 2 tracks per side using an MTH Z-4000.