Tricks with PSX power managers 

PSX circuit breakers offer the most flexibility among the various power managers on the market today. They also are some of the fastest, if not the fastest available. If you read through the instructions (I know, real men don’t read instructions) you’ll find all kinds of neat features. Among them is the ability to slow down the trip speed. This can be very helpful if you are experiencing problems with frequent shutdowns due to interactions with other devices. For example Frog Juicers are slower than the default speed setting of a PSX. Consequently when a loco hits a frog protected by a Frog Juicer the PSX will shut down before the Frog Juicer can correct the frog polarity. The PSX will keep flipping power on and off until the slower device finally catches up but this is annoying. By decreasing the trip speed of the PSX you allow the slower device time to do its job before the PSX trips.

Adjusting the speed can also be helpful when setting up situations where two PSX units are involved such as a regular PSX and a PSX-AR used in a reverse loop. If the timing is off then you can still get shutdowns when a train either enters or leaves the reverse loop. However by simply slowing down the trip speed of the unit protecting the mainline it will allow the PSX-AR to correct the short before the other PSX unit shuts down. This same strategy can be used to resolve timing issue with complex track arrangements such as back to back reverse loops.

One of the most common problems associated with circuit breakers is tripping caused by the inrush current demand when a number of sound decoder equipped locomotives are in the same block. When sound decoders start up they need to charge their capacitors which placed a large demand for current which the circuit breaker may see as a short circuit. Fortunately the PSX units have built-in algorithms that automatically help correct this. They basically can sense the difference between a short and too many locomotives or a lot of lights powered by the track.

However sometimes even the smart algorithms fail. One option is to activate the low power mode. This setting doesn’t provide a power boost of any kind, instead it simply turns the PSX on and then off again and then back on when powering up. This little trick gives the decoders on the track extra time to satisfy their current demand while allowing the DCC booster to power up as well.

If using the above tricks doesn’t solve the problem you can resort to a more aggressive option–toggles to kill track power. This is helpful in staging yards or main yards where a lot of locomotives may be left sitting, especially at the start of an operating session. By installing a toggle switch for each staging or storage track, you can control how many locomotive decoders are drawing power at any one time. This is especially useful when first powering up since you can greatly reduce the inrush current demand. Once the power is on you can flip the toggles and incrementally increase the number of locos drawing current. This has the added advantage of limiting the annoyance factor that comes with having a dozen diesel prime movers droning away at the same time.

Finally, for really difficult situations you may need to turn the auto-reset off and install a restart button. This feature prevents the PSX from automatically attempting to restore power when a short occurs. Once you clear the cause of the short you can use a pushbutton to restore power. By simply connecting a normally closed pushbutton across the terminals of jumper 7-1 and 7-2 you activate this feature. This really is an extreme measure since it basically turns your PSX into a dumb circuit breaker like those in the main breaker box in your home.

Here are links to the current manuals for the PSX and PSX-AR. Just click on the name of the one you want to download. if you have an earlier version of the PSX or PSX-AR you can contact Tony’s Trains or DCC Specialties to arrange for a firmware upgrade.


  • This is one great post! The PSX breaker are really the way to go. I have four of them and will probably get a couple more.

    I agree totally with you about installing separate toggle switches on all tracks, so that you can switch off the power. A while back I built a system for a friend that utilized a PSX for each neighborhood, and on and off toggle switches for every piece of track, no matter how long or short. This way, if a short occurred and could not be immediately found, The area could be shut down with the master switch, then all individual track sections be turned off. Then the master switch would be turned back on, and each track switch one by one, until the short “surfaced”

    I also installed an on/off switch as Larry mentioned, bypassing the auto reset, along with a Sonalert speaker system, and flashing blue light. (Sonalert on my layout only) This way you really have complete control or your system when a short occurs.

  • I am going to use an AR without a circuit breaker on a turntable. Any suggestions?

    • Ken, first when you say AR do you mean another brand such as MRC or the PSX-AR. Either way that will work fine. But do you also have circut breakers in your yard or blocks?