MTHz4000

21 volts sounds too high to me; the 8-9 amps is likely due to the passenger car lights - how many cars do you have running? fyi, (I've seen similar amp numbers on my transformers just due to many building lights).

Admittingly, I don't understand electronic circuits very well, having almost failed circuits in college. Nevertheless, I think that the higher the operating voltage - and given the demand of the car lights via high amps, a derailment or other mishap at those numbers would result in a more damaging voltage spike than if the voltage is lower to begin with.

I try to keep my Z-4000s between 16-19 volts. The amps for engines varies between 1-3, depending on smoke unit operation. Add in lighted cars, multiple engines, and the amps will go up.

Thanks Paul. I don’t have any buildings hooked up to the Z but have switch tracks. Six of them.
so once again my concern is it safe to run these units with that high amps?

I can lower the volts for sure.

I will see that amp load when I run conventionaly lighted passenger cars and have not experienced any issues with the Z4000. There are 10amp breakers on the transformer plus I use the PX-AC to protect from derailments.

I don't believe you have anything to worry about.

Running 9 amps at 21 volts will be 10.5 amps at 18 volts, so lowering the voltage won't help.

Considering Scott and John's assessment, I got to thinking about the Z-4000: it is allegedly rated at 400 watts, but in real life it may be less ~ not certain of actual output...vaguely recall Jim Barrett testing the unit and saying it was more around 360 watts ~ so that's about 180 per handle of the Z-4000.

Using P = IV; 9 x 21 = 189 watts. In theory, you're at the upper limit on the one handle of the transformer. With that said, and if memory serves me right, Lionel doesn't recommend going above 20 volts. Cannot remember what MTH recommended as safe voltage but would bet a beer that it's not higher than 20. This brings in the ancillary topic of voltage spike suppression, which is different protection than that provided from circuit breakers.

Hi MTH recommends 18 volts, but the problem is the more trains you run the higher the current will be so if you set voltage at 18 volts and are running say 3 trains as you shut one down the current draw will be less and the voltage will increase without touching anything! Lionell recommends stay under 19 volts if I remember correctly as running on higher voltage might damage electronics!

Alan

Thank all of you for your input and knowledge!

I am sure I read somewhere where you should not exceed 20 volts. I do believe it was for damaging lights in cars and houses. I did back off on that. Just fyi I got away with it-lol!

these Premier E8’s are big whines and they take a lot especially when running three at once! All of you addressed my concerns and I feel a lot better about what I’m doing.

I don’t keep the same engines on all the time and with the smaller engines there is no situation like this!

once again thank you all!!!

@Paul Kallus posted:

Considering Scott and John's assessment, I got to thinking about the Z-4000: it is allegedly rated at 400 watts, but in real life it may be less ~ not certain of actual output...vaguely recall Jim Barrett testing the unit and saying it was more around 360 watts ~ so that's about 180 per handle of the Z-4000.

First generation Z4K’s were rated 165 VA per handle. Later ones are rated 180vA. When I got my first Z4K’s I did a test by loading one up on all outputs with a bunch of surplus headlight bulbs. I found they will indeed put out full rated 400 watts, using values for V and A off the panel indicators. As soon as you nudge 400 watts total, they immediately crowbar and output goes to zero. Back off one handle slightly and full output returns.

Rod