Intermittent NCE Power Pro Short Circuit...help!!!

Model Railroader Electronics and DCC
1

Ok, where to start…

Before anything, let me state that my layout does not have power districts or short circuit protection like 12v automotive bulbs. My brother and I built it before really understanding alot about DCC.

Having said that, the Power Pro has been running fine for about 7-8 years, but recently, about a month ago, it started exhibiting peculiar behavior by shorting out randomly. I’ll be running trains, about two engines, and suddenly both locos will stop and the NCE base unit’s red light will flash for about 2-3 seconds indicating a short. Then, it will resume normal operation. After a few moments, it will do it again, randomly. Sometimes, it will do this three times a minute, other times it will be minutes in between shorts.

At first, I thought it was a loco’s decoder going bad. So I removed every loco from the rails (and any other current drawing unit, ie, sound cars and lighted cabooses, etc), but even when not running trains, the behavior still occurs.

I removed all snubbers thinking that a resistor or cap was going bad, but his did nothing to solve the problem as well.

I’ve taken a multimeter and put it in Continuity mode to see if there’s a short somewhere on the layout, but I don’t get a tone when contacting the rails. This would indicated no short present.

Now, I have noticed that during the summer months when the humidity creeps up in my basement, strange anomalies start happening. Case in point: I have flourescent ceiling lights that sometimes won’t fire up when the humidity is high. I do run a dehumidifier to aleviate some of the humidity.

Now, here’s the rub…

When all is quiet in the room, I can hear a strange sound coming from the NCE base unit. It resembles the sound of a hard drive searching for files in a computer. When I first turn the unit on, I hear the sound intermittently, then it becomes more pronounced until the unit shorts. I took the cover off and placed my ear right next to

2

I also have the 5 amp Power Pro and in 15 years the only issues I had were when a lost coupler spring had made its way into a turnout, this happened twice. The shorting was intermittent but a good magnifying glass and a big magnet tend to find stray bits that somehow make their way to places they shouldn’t.

3

Welcome Tremmy.

Your first few posts will be moderated. This will soon pass.

Without the layout hooked up does the base station still short? Are there any gaps that might have closed up? What was the last thing done to the layout? Fresh ballast? New track?

Pete.

4

You have done a good job describing the problem. My suggestion is to call NCE and describe that problem to them on the phone.

I also have a 5 amp Power Pro going on 19 years now, but I have never experienced such a problem.

They will likely want you to send the unit in for inspection and repair. But, before doing so, ask them if they have heard of this problem before and what the cause might be. That way, you can assess for yourself what exactly you are facing. Sometimes, they can resolve the problem on the phone.

Rich

5

Check the area where the sounds are coming from for dust accumulation. If you find some, clean the area with a brush and vacuum cleaner. Be usre the unit is unplugged before you do that.

Dust can cause a short.

6

To Wrench’s point, unhook the unit from the layout and power it up. Does it short out after a time with nothing hooked to it?

7

In re-reading your initial post, I wonder if the fact that the flourescent ceiling lights sometimes won’t fire up when the humidity is high provides a clue. Definitely something to consider.

There are a couple of articles on the NCE website that may be helpful to you.

https://ncedcc.zendesk.com/hc/en-us/articles/201797455-flashing-status-light

https://ncedcc.zendesk.com/hc/en-us/articles/202575119-Ph-Pro-Power-Pro-5-amp-connections-and-status-lights

Good luck!

Rich

8

Do you have any sectional track you could use to make a simple circle? If so, disconnect the base station from the layout and run a loco or 2 on the small circle for a bit to see if it still shorts out.

9

From those NCE links that I posted, it should be informative to learn more about the red flashing lights on the command station.

Rich

10

It does sound kind of like a heat-related issue where the command station warms up and then the condition triggers. So the tests of just running the command station with no track, and another with just a small circle, should both be good data points.

If it doesn’t occur with no track attached, then some current has to be flowing to make it happen. If it does happen with the small circle, then you know it’s nothing to do with your layout and it’s all on the command station.

11

I too have had nce power pro 5 for about 15+ years. Normally no issues. I have a 16x24 layout double track main and no power districts or circuit breakers, jusy one snubber at the end of the bus. I will add that I do not have a helix, any return loops, wyes or other reversing sections either. I run sound locos on a routine basis consisted with other locos, no voltage issues. The problems I have are with turnouts, while I generally have six axle locos Ive noticed that I have needed to run power feeds to the turnout running rails because Ive never had the need to power a frog. These seem to correct a lot of stops and starts. Check ALL your turnouts for loose parts that have come off. Even something as small as a staple or even a track nail stuck in a turnout will cause a short when the loco causes it to make contact. I use a shop vac once a week to keep those things cleaned out.

As far as the command station goes, have you manually turned up the voltage inside the unit? If so, its possible that its over powering and the voltage regulator is going out. I know nce says this is possible, I did it to mine and as a result, 3 years later, it was smoked. If you have not done that, then it could be an internal issue and just needs an upgrade, which it will have to go to nce for that as well. The flashing light on the front indicates a short, directly on the track because thats a track status light. If the light on the right is flashing, its the command station. Send it to nce, let them repair it and enjoy trains for the next 10 years or more.

By the way, if its the command station a booster will do absolutely nothing to stop the short. The command sration will ultimately just shut that down too.

12

Hi Batman,

I will defintely give this a try. My layout has many turnouts.

Be well!

Chris

13

Hi Pete,

No, when the track is not hooked up, there is no strange sound and no shorting. I’m just under the impression that a short is a short is a short. That’s why I don’t suspect track as causing it, but you might be right in that the track is causing something due to the summer months kicking in.

Chris

14

Hi Mark,

I will try this, thank you.

Chris

15

Hi Mike,

No, when the track isnot hooked up, it does not exhibit the bahavior, which seems to point more and more to track. It’s just that to me, a short is a shot, and not something that builsd up to a short. Very perplexing but I’ll have to check my track as others have suggested as well.

Chris

16

AlienKing,

I will give this a try tonight and see what happens. Good advice, thank you.

Chris

17

I will try putting a fan around the unti as well as doing the test trest idea. All good suggestions.

Chris

18

Hi Rich,

Sending back to NCE will definitely be the last resort if need be. Thank you for the suggestions.

Chris

19

Hi,

I opened the unit and checked the volatage via the suggested method by NCE, and the output reads 14.3V which I’m assuming is normal? I hear that N scale modellers run it at 10V.

Chris

20

14.3V is acceptable, 15.3V is normal.

What can you tell us about the flashing light?

Which light? Control Bus or Cab Bus?

Is the flashing light slow or fast, long or short?

Rich