I have a MTH orerating freight platform & a mth operating passenger platform connected togeather on the AIU. They work fine on the Z 4000 14 volt, but if I connect them to the Z 4000 10 volt they kick the breaker, help.

MONK

Last edited by james g lucas
Original Post

It could be that they require at least 16 volts to operate correctly and the 10 volt connection is "putting a strain" on the transformer and kicking the breaker.

I suspect Ron is correct, power is a function of voltage*current (yes, I am aware AC is RMS, but still), so if there isn't enough voltage it is possible they try drawing extra current to maintain the required power and that is tripping the breaker. 

That seems to be a violation of Ohm's law - lower voltage should yield less current, not more....

Does the Z4000 have a separate breaker for the 10V circuit, or some other feature that would cause breaker to trip at a lower current from the 10V circuit?

AFAIK those operating platforms use a solenoid mechanism that instantly "snaps" the freight or passengers out-of-view or into-view.   It only takes a fraction of a second for the solenoid to snap to the other position and the high power to the coil automatically turns off.  Perhaps at 10V there is not enough voltage to successfully "snap" to the other position so it keeps drawing power to no effect ... until the breaker trips.  That's just a guess.

If you have some free time, it might be interesting to connect the platform(s) to one of the Z4000 handles.  Set the handle to 10V and 14V and watch the AMPS reading on the Z4000 as you trigger the platform(s).  I figure you might not even see the AMPS flicker at 14V...but at 10V the AMPS might jump up to 3 Amps (or more) and you'll hear the platform solenoid humming or buzzing as it tries to "snap" to the other position.  The Z4000 breaker will not trip since the handles can put out 10 Amps.  The Z4000's fixed 10V and 14V outputs are 3 Amps.

Last edited by stan2004
Professor Chaos posted:

That seems to be a violation of Ohm's law - lower voltage should yield less current, not more....

Does the Z4000 have a separate breaker for the 10V circuit, or some other feature that would cause breaker to trip at a lower current from the 10V circuit?

Wouldn't that be for a resistive load only?  Many times when testing trains on the bench with a Z, at lower voltage, the current is higher.  If there is a power consumption, higher voltage requires, less current to = same power.  G

I think Stan and G identified the issue. This solenoid is an inductive load. This means a momentary but big initial in rush of current until the electromagnetic field builds. That must trip the 10 volt coil breaker.

Is it practical to hook that circuit to one of the z4000 variable handles? Then adjust the handle between 10 and 14 volts as indicated by the display while noting the AMPS display?

You should do what Stan is suggesting to get an idea on the lamp load.  Here is a thread that talked about a similar problem.  Apparently, per pictures in this thread, both the 10 and 14 volt coils are protected by a 4 amp breaker, even though they are rated at 1.5 amps.  As several mentioned above with ohms law, if this is happening with lighting only  and not a solenoid, then you have too much current for some reason.   Current will be lower (correction) at 10 volts than at 14 volts, all else being equal.  Must be something going on, the lights on those platforms are small.  Hard to believe they are 4+ watts each?   

 

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Last edited by hokie71

The 4 amp breaker on the left side blows with the power on & the handle turned down & as soon as I touch the wires to the terminals.

thank you MONK

james g lucas posted:

I'am sorry the breaker blows with just the lights, as soon as I change the connection from 14 volts to 10 volts. MONK

james g lucas posted:

The 4 amp breaker on the left side blows with the power on & the handle turned down & as soon as I touch the wires to the terminals.

thank you MONK

I'm still not understanding what you're seeing.

z4k

There are 4 breakers on the Z4000.  There is a 12A and 4A on the left rear side (Left when looking from the front of the Z4K).  These are for Track 1 (left throttle handle) and 14V.  There is a 12A and 4A on the right rear side.  There are for Track 2 (right throttle handle) and 10V.

The above photo of the Z4K outputs is from the current MTH website suggesting 3A capability on the 10V and 14V outputs.  I'm not familiar with other revisions of the Z4K that have only 1.5A for 10V and 14V as suggested in the photo by hokie71.

You say the 4A breaker on the left side immediately trips when you attach the lights.  Is this attaching to the 10V output or the 14V output or the Track 1 output?  It's confusing that the 14V 4A breaker (left side) would trip when hooking up to the 10V output or the Track 1 output.

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Last edited by stan2004

Interesting, I copied the picture from the earlier 2016 thread I referenced. No idea there were /are different versions either.

You could have a short inside the accessory.  You could have a defective 14V breaker that does not trip.   So you really need to pull the plugs out of Track 1 or 2, and hook you accessory to it, and raise the handle and read amperage.  IF it rises above 3 I would think you have a problem with the accessory.  Is it wired correctly, damaged inside....? G

GGG posted:
Professor Chaos posted:

That seems to be a violation of Ohm's law - lower voltage should yield less current, not more....

Does the Z4000 have a separate breaker for the 10V circuit, or some other feature that would cause breaker to trip at a lower current from the 10V circuit?

Wouldn't that be for a resistive load only?  Many times when testing trains on the bench with a Z, at lower voltage, the current is higher.  If there is a power consumption, higher voltage requires, less current to = same power.  G

Correct. I think you need to consider Watt's law. Some devices draw the same amount of power (watts) to operate. If they can't get it from volts, they get it from amps. These are non-resistive loads.

 

George

Last edited by George S

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