Can two wallwarts be connected to same oval?

Jan posted:

Question 1.  Can one wallwart support two engines each pulling a couple of cars?

Maybe, 3 amps available w/ small current draw...

Jan posted:

Question 2.  Can the two wallwarts be connected to the same track without danger of a polarity mismatch?

 Yes.

1.  Yes.  I do not know how much Thomas draws, but I have run several engines on one wallwart.

2.  Yes but you need to electrically isolate 2 track sections using 2 Fastrack 1 3/8 " 6-12073 pieces with the wires disconnected underneath, effectively making 2 separate circuits aka power blocks.  Each wallwart gets connected to its own isolated track section.  A wallwart has its own circuit breaker in case of a short, but 2 wallwarts on the same power block do not offer the same protection.

Old Newbie posted:

... A wallwart has its own circuit breaker in case of a short, but 2 wallwarts on the same power block do not offer the same protection.

That part is correct, the breakers will trip at 6 amps instead of 3. They do not need to be isolated.

The sets can be run from a 180 PowerHouse as well, the breaker will trip when you reach 10 amps.

Thanks to all.

I can try it with just one wart , and if needed, I can add the second.  I hoped that someone might have already tried this.

I asked about polarity because early PH180s were wired backwards from current PH180s.  You had to swap the power cord leads or rewire the Molex plug.  I didn't know if the warts could have the same problem.  The PHs have a polarity plug while the warts don;t.  The probably assume that they will always be mounted with the power cord down.  Is the output phase dependent on the orientation?  If so, one can't use the same wall plug.

It shouldn't be necessary to use insulating pins between the power districts.  The power drawn from each wart will be a function of engine locations and track resistance.

Jan

Jan posted:

I asked about polarity because early PH180s were wired backwards from current PH180s. 

 PH180s are AC, and it was a phasing issue.

Jan posted:

 I didn't know if the warts could have the same problem... The probably assume that they will always be mounted with the power cord down.  Is the output phase dependent on the orientation?

 No. The phasing is addressed in the rectification circuit.

Jan posted:

It shouldn't be necessary to use insulating pins between the power districts.  The power drawn from each wart will be a function of engine locations and track resistance.

 

 Correct, once one breaker trips, if the overload still exceeds 3 amps, the other will too.

I should have done this first; I just assumed....

The output is DC.  So it doesn't matter; I can use two or more without any problems or insulating pins.  It is like adding another battery in parallel; just doubles the current.

Thanks Rob.

Jan

it works, and have had no problems on a 2-train operation with 2 ovals with switches between them.

Whenever there is a short, you want to cut off all power to the short.  With 2 wallwarts, this may not happen.  The wallwarts auto-reset, unlike circuit breakers in house wiring.  With auto-reset, the wallwarts could keep flipping back and forth with a short, instead of cutting off all power until the short is resolved.  Sometimes even a single wallwart flips back and forthwith a short, but its individual circuitry is quick enough to flip off again to avoid problems.  And if one train stops running, the other train could keep running and crash into it, when what you want is both trains to stop on the same section (block) of track.  

I have many on my layout and they work fine together.

Chris S.