PSX circuit breaker

[Shaw]

My layout has four separate zones each isolated with Pico insolated rail joiners and each zone powered by its own bus cables through four PSX circuit breakers which are daisy chained across the top to a NCE power cab, each zones bus cables are connected from the exit terminal as per instructions. When a short occurs all four breakers trip? Can anyone suggest what I've done wrong!!!!as my understanding is that only the breaker in the zone of the short should trip.

[ISW]

1 hour ago, Shaw said:

My layout has four separate zones each isolated with Pico insolated rail joiners and each zone powered by its own bus cables through four PSX circuit breakers which are daisy chained across the top to a NCE power cab, each zones bus cables are connected from the exit terminal as per instructions. When a short occurs all four breakers trip? Can anyone suggest what I've done wrong!!!!as my understanding is that only the breaker in the zone of the short should trip.

 

I have a 'similar' arrangement; an NCE PowerCab with the track power taken through a number of MERG short-circuit devices (SCD) and then onto the appropriate track power bus. Each SCD has both wires going through it (there are no 'common' wires on the track-side of the SCDs). I have the MERGs all in parallel off the NCE, but I can't see why daisy chaining is any different. A short-circuit on one power bus trips only the appropriate SCD (if they all went off together the buzzer sounds would be deafening!), which is how it's supposed to work.

 

You do have each SCD connected to a single power bus don't you? Sorry, had to ask.

 

If you disconnect the power bus from any one of the SCDs, does a short circuit on another power bus still cause all the SCDs to trip (even the one with no power bus connected)?

 

Ian

[Crosland]

It sounds like the PSX trip level is too high and the power cab is tripping first which takes out all of the zones. 

 

Is there a visual indication that the PSX have all "tripped", rather than just lost their input?

 

Does the power cab indicate it has tripped?

 

If you disconnect the power bus from any one of the SCDs, does a short circuit on another power bus still cause all the SCDs to trip (even the one with no power bus connected)?

 

Conversely if you short the tracks together in the disconnected zone does it cause any tripping? If so, your zones are not as isolated as you think.

[Shaw]

Thanks Ian and Andrew I'll go and check but I'm sure it's all isolated and wired correctly. I will pull some wires and test each individual breaker as suggested.

[BromsMods]

As per the instructions which came with the device did you program CV49 on each PSX with a value of 01 via the PowerCab? If not, that is possibly the reason you are getting this issue, as identified by Andrew.

[Shaw]

Back from the track. Each of the zones are isolated from each other. Having disconnected each of the four boards I have tested them separately. Two trip correctly and two cause the NCE cab to turn off. When tripping the correct lights come on. I hadn't programmed each individual board separately but I have now, the two are still causing all to trip and the power cab to turn off. Will re read instructions to make sure I'm going through the correct sequence when inputting cv49.

Thanks for the help

[BromsMods]

As an alternative to programming CV49 you can also set the correct trip current for the PowerCab by making sure that J6 has jumpers across pins 1 and 2,

[Shaw]

Yes John I think that may be the way to go as when programming cv49 on three of the boards it comes up that the power cab can't read the CV? On one of the boards (the original I programmed) the cab goes through the correct set up as expected. In all cases a loco runs on each individual track zone so information is getting there.

[Shaw]

Any idea if I can obtain the jumpers from a regular electronic shop. I am not based in the UK and delivery of supplies can be irregular. What is the technical term for them.

[longchap]

Just to add a quick observation on setting the correct trip current on jumper J6, I'd just assumed that you solder a wire between pin 1 and the other relevant pin, depening on the required value for your DCC system. Take a look at the downloadable set up guide on https://www.dccconcepts.com/themencode-pdf-viewer-sc/?tnc_pvfw=ZmlsZT1odHRwczovL3d3dy5kY2Njb25jZXB0cy5jb20vd3AtY29udGVudC91cGxvYWRzLzIwMTcvMDgvUFNYLVF1aWNrLVJlZmVyZW5jZS1HdWlkZS5wZGYmc2V0dGluZ3M9MTExMTExMTExMTExMTExMTEwMCZsYW5nPWVuLVVT#page=&zoom=auto&pagemode=

 

Hope this helps.

 

Best,

 

Bill

[Shaw]

Thanks Bill, I have all the materials for that job. To un program cv49 on the circuit breaker that's accepted it do I set the value to 0?

[longchap]

I'm just finishing the wiring the branch, so stll have the PSX to fit by setting the trip current by soldering a jumper on J6, as it's simply quicker than changing CVs. Unfortunately, I'm unaware of the default CV49 value. It may be in the big PSX manual, but it takes a brave soul to go into that territory!

 

Bon courage,

 

Bill 

[Shaw]

Bill it says in the big manual not to set the CV and the jump lead. The CV value should be one, I now need to de activate on the PSX that excepted the cv. Like you say soldering the jumper is easy now I've done three. Let's see what happens!!!!

[BromsMods]

Default value for CV49 is 0.  I would have expected the required jumpers to have been supplied with the product rather than having to solder between pins, which is something that I, personally, would not recommend.  If you want to upgrade your command system to something more powerful in the future it is much easier to move a jumper on each PSX rather then have to desolder and resolder.

[melmerby]

I recently bought one of these to replace the NCE EB that had gone faulty.

I'm not entirely happy with it as it seems difficult to stop it tripping on power up. (there is about 1A of standing current from devices on or connected to the track.)

I have programmed it using the CVs rather than links and have the trip current set above the Z21's 3.2A and lengthened the response time to 128 but it still occasionally will not allow the power to the layout without tripping.

If I bypass the PSX the Z21 never trips at power on but is very quick to trip if there is a proper short anywhere on the layout e.g. derailment or me driving loco through points incorrectly.

[RFS]

2 hours ago, melmerby said:

I recently bought one of these to replace the NCE EB that had gone faulty.

I'm not entirely happy with it as it seems difficult to stop it tripping on power up. (there is about 1A of standing current from devices on or connected to the track.)

I have programmed it using the CVs rather than links and have the trip current set above the Z21's 3.2A and lengthened the response time to 128 but it still occasionally will not allow the power to the layout without tripping.

If I bypass the PSX the Z21 never trips at power on but is very quick to trip if there is a proper short anywhere on the layout e.g. derailment or me driving loco through points incorrectly.

 

Same experience - couldn't stop the PSX tripping even with max delay time. It seemed the problem was with Hornby Pullmans and their lights among other things. So I now don't bother any more with CBs and let the Z21 trip when there's a short. Usually this only happens if I'm driving trains myself rather than Traincontroller, and forget it's my responsibility to set the points correctly!

[melmerby]

47 minutes ago, RFS said:

 

Same experience - couldn't stop the PSX tripping even with max delay time. It seemed the problem was with Hornby Pullmans and their lights among other things. So I now don't bother any more with CBs and let the Z21 trip when there's a short. Usually this only happens if I'm driving trains myself rather than Traincontroller, and forget it's my responsibility to set the points correctly!

The EB 1 I had before worked perfectly until it went faulty. (The problem being it took ages to power up at switch on or after a trip, it never tripped at power on but always tripped before the Z21 with an overload.)

One of the reasons I opted for a PSX1 is the ability to set it up and switch it on & off in software but in practice it has proven difficult to use.

 

[Enterprisingwestern]

 

When I was looking for zone protection I read up on the various types of circuit breakers available, and, being somewhat of an DCC numpty, noticed people were having troubles with electronic devices such as is being discussed here.

Based on what I discovered, and the fact that I needed to keep to the KISS principle, I went with the CP6 light bulbs. So far it's worked OK, and I have the advantage of being able to turn off the layout room lights when running Heljan locos!

 

Mike.