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Old 27-12-2017, 05:08 PM   #11
RFS
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I would put money on the PSX being the problem. When it detects a short, it cuts power for 2 seconds and then restarts. What I think is happening here is that the current draw of the Pullmans is triggering an overload.

I originally had a single PSX with my Lenz DCC system. When trains with the Pullmans were running, you could occasionally see the short-circuit light on the PSX flickering, but it never actually shut down.

Then I split my layout into two power districts and purchased a second PSX. The newer unit was far more sensitive and was constantly tripping when the Pullmans were running. In the end I dispensed with the PSXs altogether.

You can try increasing the sensitivity of the PSX but I found that made no difference. Try bypassing the PSX and the problem will probably go away.

These early Hornby Pullmans don't use LEDs and consume quite a bit of power, and the problem seems to be when they lose track power through dirty wheels (there's only 2-wheel pick-up on each side) the inrush for the lights trips the PSX.
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Old 27-12-2017, 06:25 PM   #12
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Anti flicker electrolytic capacitors which the lights have in each carriage cause an in rush current every time there is a momentary loss of rail power or at power up. The in rush current exceeds the PSX or can at times also exceed the trip current threshold of the main DCC system.
Try removing all but one lit carriages then test to ensure loco and carriage runs OK. If OK add a second carriage and test and so on.
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Old 27-12-2017, 11:32 PM   #13
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Sounds as though the PSX could be the problem, they are brand new so I will check with supplier to see if there is any adjustment.
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Old 28-12-2017, 09:34 AM   #14
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Quote:
Originally Posted by johntgillott View Post
Sounds as though the PSX could be the problem, they are brand new so I will check with supplier to see if there is any adjustment.
John, go back to the instructions and programme the unit using your DCC system to a lower sensitivity. There is a section that talks about using the PSX with an auto reverse module (I had to do it on mine).
From memory there is a jumper plug that has to be moved to a different pair of pins, then using your handset programme and anunused loco address (I used 1) there is a CV that can be adjusted. They recommend a setting for the PSX-AR but you may have to experiment for your issue.
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Old 28-12-2017, 09:58 AM   #15
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There are adjustments to the sensitivity of the PSX that are not included in the instruction sheet. Assuming your PSX is relatively new, you can adjust CVs as per this article here -

http://www.dccguy.com/?p=3840

However, I tried this with my PSX and even at maximum adjustment it still tripped with the Pullmans, but see if it works for you.
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Old 28-12-2017, 10:20 AM   #16
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The instructions do now include details of all the CVs that can be adjusted on the PSX1 - see link:

http://www.dccspecialties.com/products/pdf/man_psx1.pdf
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Old 28-12-2017, 10:51 AM   #17
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Quote:
Originally Posted by Steve M View Post
The instructions do now include details of all the CVs that can be adjusted on the PSX1 - see link:

http://www.dccspecialties.com/products/pdf/man_psx1.pdf
A much improved manual that appears to be dated October 2017. Basically what you need to do is to go into programming mode, set CV 55=1 and CV 65 to a value between 1 and 255.
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Old 03-02-2018, 11:06 PM   #18
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Thanks Guys, 4 coaches run ok I will try and adjust psx1's
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Old 09-02-2018, 06:42 PM   #19
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Hi Guys I took the easy way out and inserted jumpers in terminal block J6 as per instructions, everything works perfectly now. Once again thanks for all the help
John
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Old 09-02-2018, 07:39 PM   #20
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If you have jumpers in J6 they need to set a trip value that is below that of your DCC system. If the PSX trip value is too high, then a real short circuit will trip your DCC system first. I assume you've checked that though!
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