I’ve been running multiple engines via DCS with a z400 on two tracks. I’ve been experiencing shorts that trip the break and I am unsure as to why. Is it possible that running too many engines could cause a short?
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Yes, but you would need to be running at least 5 engine on one channel. How many amps is the digital meter reading? Do you have lighted cars?
George
You didn’t specify what is happening when the short occurs. Do you only reset the breaker and magically everything works until next time? I agree with George that it is not the number of engines. I run mostly command equipment but do run a postwar F3 and MPC era GG1 and some other things with AC motors. Even with 5 lighted cars I have never seen more than 6-7 amps on my Z and I have never tripped the circuit breakers.
You don’t mention what you are running but I will venture a guess that, at least, one piece has an issue. It could be a bad motor or drive line, loose or frayed wires or something hitting the center rail. You are going to have to run each piece until you find the culprit.
Peter,
The Z-4000 has 12 amp breakers, so check your amp draw on the transformer amp meter.
Joe Allen posted:Peter,
The Z-4000 has 12 amp breakers, so check your amp draw on the transformer amp meter.
At 18 volts on a handle, the Z4000 will power down at or before 10 amps without tripping the breaker. The max wattage on a handle is 180 watts. The power label says 165 VA, which would be a little over 9 amps at 18 volts. So, what do the meters read when you have the problem?
George
Hi George,
The only Z-4000 rated at165 VA was the first run from March 1998. The ones from the second run on are rated 180 VA. I have both and they have 12 amp breakers.
If you are using the Z-4000 side receiver, it will shut down the transformer at with the least little short or spark extremely quick, which I use most of the time.
Using the Z-4000 without the side receiver you should be able to run up to 11 to 12 amps with no problem, at least I can. I just got a chance to make sure I was right by running 3 loops and 3 engines plus passenger cars on 1 TIU channel today without the side receiver. 
Joe Allen posted:Hi George,
The only Z-4000 rated at165 VA was the first run from March 1998. The ones from the second run on are rated 180 VA. I have both and they have 12 amp breakers.
If you are using the Z-4000 side receiver, it will shut down the transformer at 9 volts with the least little short or spark extremely quick, which I use most of the time.
Using the Z-4000 without the side receiver you should be able to run up to 11 to 12 amps with no problem, at least I can. I just got a chance to make sure I was right by running 3 loops and 3 engines plus passenger cars on 1 TIU channel today without the side receiver.
Hi Joe,
Running 12 amps at 18 volts would be 216 watts, which would exceed the rating of the unit. If the amp rating actually controls the unit, which I doubt, the most you could theoretically run at 12 amps would be 15 volts. Most people run command (DCS with a TIU) at 18 volts. That means the breaker is over-rated at 12 amps. It should be 10 amps, unless there is circuitry in the Z4000 that prevents it from driving to 12 amps at 18 volts. This is Watt's law.
George
Überstationmeister posted:Under normal use, the electronic breaker circuitry intervenes when 180W at 10A continuous is exceeded at any voltage, although brief excursions up to 12A are possible (red light will flash). The physical 12A thermal breaker is a last resort safety that is virtually impossible to trip unless operated near 9.9A for a prolonged period.
*Note that any attempt to cross-connect the throttles also results in an overload indication and may trip the physical breakers as well.
Ok, but 180 watts at 10 amps is 18 volts. Really, this is just math. The handle sets the volts. Amps increase based on load. If there is an overload or short, the amps will exceed 10 amps until circuitry, breakers or failure intervenes.
George
