OK, so over the weekend I dismantled the rest of the FasTrack Carpet Central and setup the Atlas 21st Century Track System Carpet Central Test Track (guess that would be ACTSCCTT)… wanted to see if I could correct the mistake I made on the Williams Baldwin Shark upgrade.
Took the rear facing A-Unit apart, switched the trucks, remounted the E-Unit (this is necessary because the wires on the forward powered truck are much shorter than the rear powered truck… put her on the track, applied power, she moved nice and smooth. [tup]
Hooked up the forward A-Unit, powered up… they moved nice and smooth in tandem…
Hooked up the B-Unit… moved nice and smooth, powered up… kept moving nice and smooth… but as soon as I hit 14 on the Modern ZW Throttle - TRIP - Power DEAD.
So I removed the B-Unit… can get all the way to 16 (can’t go higher because the engines start to L-E-A-N around the O-45 curves…
I tried all combinations of 2 engines and they run fine (so it appears NOT to be the wiring on any of the engines)… I also hooked up the 7 madison passenger cars to the 2 engine tandems and everything is fine (can get up to 18 with no problems, but around 18.2 the observation car becomes a hostile projectile upon exiting the first curve - was really cool, wish I had a video of it… it shot off the track, remained upright, and stopped right behind the off-track A-Unit! LOL!)…
So the question is… WHAT IS HAPPENING??? I thought I should have no problems powering 3 engines and running them on the same loop. Do I need additional power drops? I am only using the power leads that Atlas sells (I think 22 or 20 gauge wire), or should I try 16 guage and multiple drops? Almost forgot… this is 1 complete O-45 circle with 8 straights…
Brent, I am using 14 gauge wire to power every section of my track. Something about B unit is drawing too much amperage. Have you run them all three together before? Maybe Bob Nelson can help. I’ll email him and see if he replies.
Chief - I ran them all together before, but had the trailing A-unit wired wrong, so it was going the opposite direction of the other two engines.
I can run 1 A-Unit with B-Unit, or A-A no problems… it is as soon as I put the third engine on that this happens.
I am planning to open all of them again, lube them and oil them, and also check the trucks on the second A-Unit to make sure the motors are seated properly (had some troubles with the one motor, but I thought I had it right). Also may loosen the screws a 1/4 turn to make sure I don’t have things torqued too much.
Morning Brent, it’s hard to help without being there. Something is drawing to much current a newer zw should handle what you describe but I don’t have one to compare(I have 2 pw). power every thing up sit in neut. then run you hand around the track feeling for hot spots. you may have a bad connection using atlas track connectors.
OK… that I can do without spending too much time on it! LOL!
One more question… what is the proper behavior for Williams engines when you first power up… should the engine move (as a PW engine would), or should it sit in neutral - like a TMCC engine would? I assume it would be the PW behavior?
Brent- read your question, I have an F3 that has not been run for awhile. Put it on the track it started in forward. I let it sit about 30 sec. and it started it forward again.
Bad connections and too-small wire would only decrease the current drawn; so I doubt that’s the problem. I don’t know anything about the insides of the modern "ZW’; so I won’t try to explain its behavior.
(That wire you’re using is safe for only about 4 amperes. It won’t solve you problem, but I would upgrade it to whatever your transformer can put out, if you can figure that out. Fourteen AWG is good for 15 amperes.)
Those meters almost certainly are accurate only with a sinusoidal waveform, such as you would have with pre-modern “transformers”, which are true transformers. They would not be accurate with a CW80. I don’t know about a modern “ZW”, but I am not optimistic.
Perhaps if you put them on the inlet to the ZW (outlet of the bricks?). Or maybe you have a friend with an MTH or ??? unit. Some of the large transformers have amp meters.
If the “ZW” is using a high-frequency chopping technique, its output is probably virtually sinusoidal and the meter would work. But, if it is using phase control, like the CW80, an ammeter on its input would have the same problem with the waveform as an ammeter at the output.
An ordinary AC ammeter on the sinusoidal output of a transformer or “transformer” will read correctly only if the load is linear. If these “bricks” are something like phase-control modules meant to be fed from a true transformer, it won’t work to put the ammeter between the transformer and the “brick”, since the “brick” will draw non-sinusoidal current from the transformer, just as a CW80 draws non-sinusoidal current from the power line.
You can of course use an ordinary ammeter if you want, as a rough indicator, if you don’t mind the inaccuracy. However, what you really need is a true-RMS ammeter. Which will not come cheap.
Questions whose answers depend on what’s inside a modern “ZW” keep popping up. Is there anyone who has any technical information about them? Or about the “bricks” or whatever else is used with them?
The startup behavior of a locomotive with an electromechanical e-unit can be any of four possibilities, depending on what it was doing when last turned off.
I received my trains back from Jumijo… very nice… put the 681 and 4 post war passenger cars on the test track, every once in a while the Whistle would start blowing… shut down, disconnected the ZW, hooked up KW… no problems… took off 681, hookedup the Williams engines… no problems all the way to 18 volts…
I don’t know anything about the units you are running or your power supply but lets just apply some numbers that fit Ohm’s Law…
Each unit draws a current that is proportional to the voltage applied.
If you apply one Volt to one unit it will draw a certain number of Amps. You apply 2 Volts and it will draw twice as many Amps. Just for grins (and I must point out that these numbers are just for example and do NOT really represent your true situtation):
Say you apply 1.0 Volt and it draws 0.1 Amp, you increase the Voltage to 2.0 Volts it will draw 0.2 Amps. Apply 10.0 Volts and it will draw 1.0 Amps.
Now if you put two units on the circuit EACH will be drawing the same current from the same Voltage. Thus, you apply 1.0 Volt, they each draw 0.1 Amps, thus the total current draw is 0.2 Amps. Apply 10.0 Volts and the total current draw will be 2.0 Amps.
If your power supply can supply 2.0 Amps, then you have no problem.
BUT, if you put a thrid unit on the circuit at 10.0 Volts, then the total current draw will be 3.0 Amps and if your power supply has a fuse (or circuit breaker) that trips at 2.5 Amps, then the circuit will shut off to protect the power supply from overheating.
Note that 3 units could run at just 5.0 Volts because each would be drawing just 0.5 Amps making the total current to be 3 times that, or 1.5 Amps, which is below the trip point of the power supply.
Ain’t it just that simple? Or am I missing something?
I’m not an EE so I have no idea… I did send an email to Lionel today to see if they have any suggestions… typically it takes them a couple days to responde.
Well, yes, Charles, you are missing something. Ohm’s law applies to resistors, not to motors and incandescent lamps. For example, with lamps, dropping the voltage from 10 to 5 causes the current to drop 32 percent, not half. Motors are even more squirrelly. But it is generally true that, for both kinds of loads, decreasing the voltage will decrease the current, just not proportionately. I think that’s enough to make your valid point.
Agreed, there is a whole lot more to it, (back EMF, etc.) but my point is that at a lower voltage the power supply might be able to provide the necesary current to run 3 units, whereas at a higher voltage that can run two units, the third one presents an overload condition.
Actually, if you could get the engines running the increased speed might create enough back EMF to reduce the current to an acceptable level for the power supply, but the startup current is exceeding the supply’s capability.