NCE PowerCab and a current draw issue

[B McG]

Good evening and Happy New Year to you all.

 

Since last year I have been building a largish layout in a 20 x 11 shed in my back garden. I haven't long got all the track down and have been wiring the droppers in the main bus.   For each dropper I've been fitting these every 1.5 meters on average (based on my previous experience on my dismantled garage layout) with all pointwork isolated and with it own droppers. I have been using PL-81 Peco power feed joiners for ease and simplicity of fitting, then soldering on on the ends some 18awg wire which then attaches to the connector block which in turn has power supplied by the main bus.  For the main bus I used solid core 13amp rated electrical cable.  I have separated the layout into 5 separate power district as shown in the attachment.

 

I had 70% of the layout wired in when I started to wire the droppers in the main bus feed for that power district (no.3) on the upper level storage roads when the problems started. After wiring each point in I would run a loco to test it was working as expected.  When I had the first fan of points wired in it was that this point that when I ran a loco above half speed the controller would reset, and it was clear something was tripping.  Thanks to gathering some tips on here I activated the amperage feature on my powercab (until now I didn't know about that!) to discover the layout was drawing 2 amps which is on the cusp of the controllers capability.

 

So I humbly ask for advice on this on the basis there is no such thing as a stupid question.  Firstly I think I've made a significant mistake firstly by using so many PL-81's on the layout.  Also it's my first experience with using gaugemaster BPDCC80 frog juicers on each point.  My line of thinking is that with both the cumulative effect has increased the current draw to the point where the controller will trip.

 

In terms of remediating the situation would I be right in ditching the power feed joiners and soldering on 18 gauge droppers directly? Also am I right in thinking each frog juicer draws 20mA?

 

Thanks in advance for any replies received.

Power district schematic.docx

Edited January 1, 2022 by B McG
Spelling mistake

[Pete the Elaner]

As far as I know, the Powecab itself doesn't actually reset, the power supply does. Either way, you don't want to be overloading your Powercab.

How much current does the layout draw when no locos are on it? This will be useful to know.

I have had a quick count of your points & it looks like you have over 50. If Gaugemaster's juicers consume 20mA each (which seems reasonable although I haven't checked) then this will be 1A, which leaves a further 1A(ish) for everything else.

You've not mentioned what point motors you use. A stalling type (eg a Tortoise) will consume some current all the time & 50 of these will add up. A solenoid type will take a short burst & throwing a point will create a short blip, although a CDU will smooth this out a lot.

 

When running a loco, does it suddenly cause an increase in current consumption when it reaches a certain location? If it does then it its location may be where your issue is.

 

All decoders draw a little current even when they are not doing anything. As with accessories, this is minimal per loco but if you have 20-30 locos, it can be significant.

Some locos are more power hungry than others. Heljan locos are known to draw a lot of current, maybe up to 1A for 1 loco if it is under load.

It could be that your layout is simply too large for a 2A system, but it is useful to know for certain.

If you do need more current, then a booster can be added. The Powercab is a very expandable system.

 

[AndrueC]

I have a much smaller N-scale layout (2x1.5m) and with 7 locos idling, three LEDs, LED controller and three turnout motor controllers I'm at 0.56 amps. Back when I only had the locos I was at 0.28A. So on that basis if I had 50 turnout motors (which with mine would mean 25 controllers) I'd be looking at over 2A before I even put a loco on the track. Now my controllers/motors are a different make to yours but it suggests to me that at 2A there's nothing wrong with your wiring. It's just a big layout and you need to add one or more boosters.

 

But there are different ways of going about that so hopefully someone with more knowledge can chime in.

 

Oh, but I have to ask: Are you using the original PowerCab cable? I bought a longer one and that caused problems. If you don't have the PowerCab booster then all your power is going up to the handset and back again and a standard replacement cable is going to cause problems.

 

Edited January 1, 2022 by AndrueC

[B McG]

Thanks for responding.  The layout I'm building is 19 by 10 feet and based on 20 mAmps and I won't have the power budget to run that many, as I suspected.  The powercab picture was with a DCC loco at rest on the track at 1.98 Amps with the storage roads unhooked!  Little wonder when I connected the storage roads in that the power supply would trip every few seconds when I went above half throttle.  

 

I'm more relaxed about point motor control, I have a separate power supply to run the point motors along with a couple of CDU's.

 

I'm not sure I could use a 5amp SB5 though as looking at the gaugemaster BPDCC80 frog juicers spec sheet they are only rated for 2 Amps.  A major rethink may be on the cards!

 

Edited January 1, 2022 by B McG
Edited for further detail

[Pete the Elaner]

14 minutes ago, B McG said:

 

I'm not sure I could use a 5amp SB5 though as looking at the gaugemaster BPDCC80 frog juicers spec sheet they are only rated for 2 Amps.  A major rethink may be on the cards!

 

 

5A is what the power supply is capable of delivering. It will only supply what the individual components collectively draw.

Assuming that the juicers collectively draw 2A, then this only leaves 3A for everything else. Only what is drawn from the loco on the point frog will actually pass through the juicer supplying it. You could theoretically have a loco which draws more than this, but the same loco would already be overheating your wiring & rails (& if you rely on rail joiners for conductivity, they would likely be glowing by this point).

[B McG]

25 minutes ago, Pete the Elaner said:

 

5A is what the power supply is capable of delivering. It will only supply what the individual components collectively draw.

Assuming that the juicers collectively draw 2A, then this only leaves 3A for everything else. Only what is drawn from the loco on the point frog will actually pass through the juicer supplying it. You could theoretically have a loco which draws more than this, but the same loco would already be overheating your wiring & rails (& if you rely on rail joiners for conductivity, they would likely be glowing by this point).

 

Really big thanks for that!  I am a bit naive when it comes to electrics, but this advice really helps. As I only will be running a maximum of three locos the SB5 will be plenty.  I spoke with the wife who's happy for me to get an SB5 in the next couple of months along with short protection.

 

I like what you are doing on your layout to a skill level beyond what I am currently capable of. I hope you've had the time over the Christmas period to work on it!

[B McG]

1 hour ago, AndrueC said:

I have a much smaller N-scale layout (2x1.5m) and with 7 locos idling, three LEDs, LED controller and three turnout motor controllers I'm at 0.56 amps. Back when I only had the locos I was at 0.28A. So on that basis if I had 50 turnout motors (which with mine would mean 25 controllers) I'd be looking at over 2A before I even put a loco on the track. Now my controllers/motors are a different make to yours but it suggests to me that at 2A there's nothing wrong with your wiring. It's just a big layout and you need to add one or more boosters.

 

But there are different ways of going about that so hopefully someone with more knowledge can chime in.

 

Oh, but I have to ask: Are you using the original PowerCab cable? I bought a longer one and that caused problems. If you don't have the PowerCab booster then all your power is going up to the handset and back again and a standard replacement cable is going to cause problems.

 

 

Thanks for this, it's all too clear that the number of points with juicers is clearly the issue when I have only 2 amps to play with. 

 

I bought my powercab back around 2011 with all the original accessories.  It served my 7 by 12 garage layout well before I upscaled beyond the power it could supply! 

[Pete the Elaner]

15 hours ago, B McG said:

 

Really big thanks for that!  I am a bit naive when it comes to electrics, but this advice really helps. As I only will be running a maximum of three locos the SB5 will be plenty.  I spoke with the wife who's happy for me to get an SB5 in the next couple of months along with short protection.

 

I like what you are doing on your layout to a skill level beyond what I am currently capable of. I hope you've had the time over the Christmas period to work on it!

 

You took a peek at my layout? I've stalled a little on that lately. just doing other things really. The layout is not going anywhere & I have previously taken long breaks from the hobby before returning so there is no reason why I won't get back to it at some point.

 

15 hours ago, B McG said:

 

I bought my powercab back around 2011 with all the original accessories.  It served my 7 by 12 garage layout well before I upscaled beyond the power it could supply! 

 

& that is the a thing about a Powercab.  Upgrading it is very affordable. You only need to buy the modules you really want & building the system like that is barely, if at all, more expensive than buying the expensive "all in" version in the first place.

[ISW]

21 hours ago, B McG said:

Really big thanks for that!  I am a bit naive when it comes to electrics, but this advice really helps. As I only will be running a maximum of three locos the SB5 will be plenty.  I spoke with the wife who's happy for me to get an SB5 in the next couple of months along with short protection.

As an alternative to the SB5, have you considered using a separate power supply for the non-track electrics (point motors, CDUs, etc.)?

 

That's the arrangement I have, including a PowerCab for just the track power. All my turnouts are servo operated (and controlled by MegaPoints controllers) and those are served by a dedicated 12v DC supply. For that supply I simply re-purposed an old XBox power brick, which (being for a computer) gives a very steady 12v and at up to 14amps! Plenty for your CDUs. The XBox power supplies are readily available, I got mine at a car-boot for £1. However, you'll be able to pick one up (or something similar) for ~£20 - £25.

 

With just the track to power, the PowerCab is more than capable of running 3 or 4 trains. The most I ever seen on the display is 1.1amps, and I have steep gradients.

 

Ian

[Mallard60022]

Is this any help? I have an upgraded PowerCab. I run it on and 18V supply (controlled). I have two TAM juicers at 6 outputs each (to non motorised points at the moment; will be Baseboard Peco P11s[?] fed from 15vDC). 10 DCC Cobalts on 15v DC Power supply, NOT off the DCC BUS and several Gaugemaster Frog Solenoids (are they DC8s or something?) on not motorised points at the moment, they are just joined to Frog and track. I also have 10 Peco Board Top (P11s?) points driven off DC and micro switches.

With 6/7 loco's sat on the layout at present my current draw is small 0.2Aish. With two Loco's running on 10 Coach Trains, the draw is around 0.60 - 0.75A I think it is

My Point motors do not draw their switch power from the DCC Bus.

I am also carp at electrics, but that looks a high Draw on your Cab.

Phil

Edited January 2, 2022 by Mallard60022

[B McG]

Following on from this thread I took the plunge and pre-ordered an NCE SB5.  A while ago I bought a PSX1 short protection board and have been mulling whether to get a PSX4 to complete out the 5 power districts or whether I should go with 5 x EB1 v1.1. I'd be interested if anyone can recommend which would be the more suitable. 

 

The other thing at the moment is that neither seem to be available in the UK, so if any alternatives are out there I would be interested to hear!

 

Cheers

Bryant

[ISW]

14 hours ago, B McG said:

The other thing at the moment is that neither seem to be available in the UK, so if any alternatives are out there I would be interested to hear!

 

Cheers

Bryant

Bryant,

 

Being something of a cheapskate I went with a kit from MERG, specifically Kit #57 "Short Circuit Protection". I have a total of 8 Power Districts on my layout, each protected by a Kit #57. My controller is an NCE PowerCab. They work really well, and are fast enough to respond before the PowerCab protection kicks in. Having separate Power Districts is really nice on a large-ish layout as only that 'area' stops as a result of a short-circuit. Kit #57 is self-clearing, in that it automatically restores power once the short-circuit has been removed.

 

When I bought them a few years ago they cost ~£12 each.

 

 

I had no trouble assembling the Kits, although you do need to be 'competent' with a soldering iron. The instructions are nice and clear, and include 'testing'.

 

Here are 6 of the Kits installed on the underside of one of my Upper Level baseboards (2 more are on the Lower Level):

 

Ian

 

Edited May 26, 2022 by ISW
unnecessary details removed.

[RedgateModels]

Nice, I had a hand in helping testing the DC01 (was BC01 back then) as I had a Dynamis at the time and no-one else produced a cutout that was fast enough for it. Even made my own PCB as there was no kit back then of course. I hope you don't ever have a system wide short with all those sounders LOL. I prefer to mount a board edge LED instead 😉

 

Here's MK1 in all it's glory

 

 

I hope you can become a member sometime

Edited May 26, 2022 by RedgateModels

[ISW]

1 hour ago, RedgateModels said:

I hope you don't ever have a system wide short with all those sounders LOL.

It's not happened yet but, yes, it would be rather loud. Can't complain though, those buzzers do 'get your attention' (aka jump-out-of-your-skin).

 

1 hour ago, RedgateModels said:

I prefer to mount a board edge LED instead 😉

Agreed. I do have 'plans' to built a small plywood box with labelled LEDs (maybe an old plastic container would do?) with a fly-lead and plug/socket connecting it to the Kits. Most of the time I can tell/know which Power District has tripped, although there have been a couple of occasions where I had to look under the baseboard to see which LED was lit to identify the Power District. The vast majority of my short circuits are caused by a loco trailing an electrofrog turnout when the turnout is set to the wrong direction.

 

1 hour ago, RedgateModels said:

I hope you can become a member sometime

I've been 'close' to becoming a member a few times, including at Model Shows where MERG was exhibiting. As I plan to purchase the Kit #59  & 774 combo (5 amp Booster) to, eventually, upgrade my PowerCab to 5amps that'll probably provide the impetus to join!

 

1 hour ago, RedgateModels said:

Here's MK1 in all it's glory

I can see the resemblance to the assembled Kit #57. The only major difference is that adjustable pot. I take it that was replaced with the bank of selection jumpers in the final kit?

 

Ian

Edited May 26, 2022 by ISW
added quote.

[RedgateModels]

17 minutes ago, ISW said:

As I plan to purchase the Kit #59  & 774 combo (5 amp Booster) to, eventually, upgrade my PowerCab to 5amps that'll probably provide the impetus to join!

 

I can see the resemblance to the assembled Kit #57. The only major difference is that adjustable pot. I take it that was replaced with the bank of selection jumpers in the final kit?

 

Ian

 

MERG are currently working on a replacement for the NB1 booster the NB2 as components in the NB1 are becoming obsolete, also will support Railcom (if you need that) - I'd highly recommend joining at this point as you may need help with integrating a merg booster with the Powercab.

 

The pot was to adjust the speed of reaction to a short - from 200 microsecs minimum to 65 milliseconds maximum - a key part of the design so it could be fine tuned to Dynamis etc - now done with jumpers S0 to S3

 

Hope this helps

 

 

[Nigelcliffe]

4 hours ago, RedgateModels said:

 

MERG are currently working on a replacement for the NB1 booster the NB2 as components in the NB1 are becoming obsolete, also will support Railcom (if you need that) - I'd highly recommend joining at this point as you may need help with integrating a merg booster with the Powercab.

 

 

Railcom cannot work with NCE kit(*).   That won't stop the MERG booster working with the NCE system as a DCC booster. 

 

(*  That's a "cannot" not a "can work if you add third party stuff".     ). 

 

- Nigel

[RedgateModels]

Cheers Nigel for the clarification. I just mentioned it as it's a new thing with the NB2 :)