NCE Power Cab + DCC-C Cobalts = short circuits?

[imt]

Please excuse me I have been overwhelmed by my ignorance and would appreciate some guidance from more knowledgeable/better qualified persons than myself.

 

Background: My layout is a small BLT with 4 road fiddle yard.  I have a NCE power Cab with an NCE ProCab as a slave.  I have a "control box" (as you do) with buttons to set routes and multi-colour LEDs to show how signals are set.  The output is through NCE Mini-panels onto the NCE bus (via a standard NCE face-plate) - so nothing I have done should affect that output, which will be a string of accessory commands in DCC format on the NCE PowerCab supplied power.  I have been running thus for some time with no (apparent) problems.  For wiring convenience I had split the power out from the NCE face-plate into 4 feeds (Power Districts) 1 for the main station, one for the complex Quayside that I have, one for the fiddle yard and one for all the accessories.  So all accessories are powered and DCC commanded from one bus.

 

Failed DCC-Cobalt: One of my Cobalt point motors failed.  I took it out and returned it.  They kindly fixed it and returned it saying that the electronics had been damaged by a short circuit.

 

Insertion of NCE CP6 (car lights?): I felt uneasy, so before I put the Cobalt back I bought an "NCE CP6 Circuit Protector" specified for the PowerCab and wired that in after the faceplate.  The the CP6 also splits the output into 6 - I needed 4.  I have tested the 3 supplies to trackwork and they work fine - short on one circuit does not affect another and the bulb lights.

 

PROBLEM:  Light on PD4 - the accessories bus - glows at varying brightness whenever a string of commands is sent out by the Mini-panel (a route might be several points and a signal say). Horror! Aghast I tried using just the NCE PowerCab handset to send single commands to an address - some are single points, some are crossovers with 2 points on the same address, some are signals (TrainTech DCC or CRS with TrainTech DCC controllers). Signals change without the bulb glowing, single points change with a small glow, crossovers cause a brighter (but still small) glow. Aaaaaaaaaaaaaargh!  What am I doing???  It seems to be just the Cobalts and the more the brighter (if you see what I mean!).

 

Question: Am I over-reacting?  Is this actually OK?  Should Cobalt point motors somehow short ciruit the supply - HELP PLEASE.

 

EDIT:  I just realised of course that it is not a "short" necessarily but maybe an over demand on the supply?

Edited July 17, 2018 by imt

[Mallard60022]

I know this sounds odd but maybe you actually do not have enough power going into your BUSes? I had problems recently with Power Cab with original power supply (12wV @ 1.5A I think it was) and all sorts of stuff happened, including frog juicers not working and getting really hot. I/we discovered it was lack of power ending up at the BUSes for a couple of reasons and lo, not enough power to throw the relay in the DCC 80 juicers that were then not throwing and possibly burning out had we not noticed. I tried the CP6 as I was also paranoid about blowing something else up. It absorbed even more power and lamps glowed for reasons I do not understand! (Power at the track was down to about 10.4V). Anyway, I have upgraded to 13.8V @ 1.8A NCE supply and now have 11.6 V operational across all 3 BUSes/Districts with two loco's working on heavy trains, on a large 24' X 10' circuit main line layout. I am not using the CP6 at the moment and all the 'problems' have gone away........................arggghhh, am I tempting fate?

Apologies if this is totally irrelevant to your situation and good luck.

Phil

 

P.S The new NCE power supply cost me £16 but I actually found (just after ordering of course) a 13.5V @ 1.5 A PC charger that worked just as well and cost me nothing....pah!

Edited July 17, 2018 by Mallard60022

[WIMorrison]

I got rid of the 'glowing bulb' protection method and replaced them with NCE EB1 power breakers which are much more effective.

[imt]

I got rid of the 'glowing bulb' protection method and replaced them with NCE EB1 power breakers which are much more effective.

 

Quote from their NCE EB1 web page "This is not recommended for use with the Power Cab. For the Power Cab use the CP6. ".  So I did that!

[imt]

I know this sounds odd but maybe you actually do not have enough power going into your BUSes? 

 

I hear what you say.  I MIGHT believe that if anything else (i.e. locos) were drawing power.  They are on the track, but nothing moving.  

[Nigelcliffe]

The "light bulb" protection method is not a protection against short circuits, instead it limits the maximum current flowing through the bulb, and in turn, limits the maximum power drawn from the command station.   At low currents, the resistance of the bulb is low and it stays dark.  As the current rises, the bulb's resistance increases, the filament glows and light/heat comes from the bulb.  

 

So, what you appear to be seeing is a current draw of above 0.5A, and possibly approaching 1A  (the usual limit of the NCE bulbs).    As the bulbs are rated at about 1A each, then a Powercab will still be overloaded if three light, and possibly overloaded with two lit. 

 

 

An additional factor with "Cobalts" is "which model of Cobalt, and how is it wired ?"    If you are using the Cobalts which come with the integral frog switch, and you are using that frog switch output, then your frogs are powered from the Accessory bus.   That has consequences should there ever be short circuits at the frogs as power is coming in along track bus and out via accessory bus (or visa-versa).   The solution to this is to not use the "rather too clever for its own good" frog output, but instead switch a frog using the other accessory switch with two wires in from the track bus and one out to the frog. 

 

And finally, what track, and how is that setup ?   Again, I've seen people use unmodified N electrofrog turnouts (think the same is possible in other scales), then connect a wire to the frog, and wonder why there are shorts when the turnout motor is operated. (because the switch on the turnout motor and the switch at the point blades move at different times, so there IS a short until both have moved enough.). 

[Mallard60022]

Quote from their NCE EB1 web page "This is not recommended for use with the Power Cab. For the Power Cab use the CP6. ".  So I did that!

Absolutely. Do not use EB1s with Power Cab.

Apologies that my psot was of no use. It was just a thought.

Nigel's is a really helpful post; I would never have considered that problem with the motors. I think I would wire mine mthat way as they are gradually replacing Gaugemaster DCC 80 single juicers/switches.

Phil

Edited July 17, 2018 by Mallard60022

[WIMorrison]

Quote from their NCE EB1 web page "This is not recommended for use with the Power Cab. For the Power Cab use the CP6. ". So I did that!

I wasn’t aware of the limitation - what is so different with the powercab that a circuit breaker won’t work with it? I used it on my Lenz and now in Z21 without any issues.

 

Just interested to know why they rely on very old school ‘protection’ which as mentioned doesn’t provide a lot of protection as the reaction time for bulbs is very significant.

[Nigelcliffe]

I wasn’t aware of the limitation - what is so different with the powercab that a circuit breaker won’t work with it? I used it on my Lenz and now in Z21 without any issues.

 

Just interested to know why they rely on very old school ‘protection’ which as mentioned doesn’t provide a lot of protection as the reaction time for bulbs is very significant.

 

The EB1 trips at too high a current to be of any use for a PowerCab.  The PowerCab would already be at overload before the EB1 trips. 

 

- Nigel

[Mallard60022]

The EB1 trips at too high a current to be of any use for a PowerCab.  The PowerCab would already be at overload before the EB1 trips. 

 

- Nigel

I have always liked Power Cab but this is one of the main weaknesses. However I have read of many solutions, mostly including the use of Car Headlamp Bulbs.

Presumably the CP6 bulbs absorb power up to a certain point and this should protect the Cab. 

Interesting problem though that the OP has. I'm interested in what he discovers.........I hope he does discover the solution.

Phil

[imt]

The "light bulb" protection method is not a protection against short circuits, instead it limits the maximum current flowing through the bulb, and in turn, limits the maximum power drawn from the command station.   At low currents, the resistance of the bulb is low and it stays dark.  As the current rises, the bulb's resistance increases, the filament glows and light/heat comes from the bulb.  

 

So, what you appear to be seeing is a current draw of above 0.5A, and possibly approaching 1A  (the usual limit of the NCE bulbs).    As the bulbs are rated at about 1A each, then a Powercab will still be overloaded if three light, and possibly overloaded with two lit. 

 

 

An additional factor with "Cobalts" is "which model of Cobalt, and how is it wired ?"    If you are using the Cobalts which come with the integral frog switch, and you are using that frog switch output, then your frogs are powered from the Accessory bus.   That has consequences should there ever be short circuits at the frogs as power is coming in along track bus and out via accessory bus (or visa-versa).   The solution to this is to not use the "rather too clever for its own good" frog output, but instead switch a frog using the other accessory switch with two wires in from the track bus and one out to the frog. 

 

And finally, what track, and how is that setup ?   Again, I've seen people use unmodified N electrofrog turnouts (think the same is possible in other scales), then connect a wire to the frog, and wonder why there are shorts when the turnout motor is operated. (because the switch on the turnout motor and the switch at the point blades move at different times, so there IS a short until both have moved enough.). 

 

Thank you for your thoughtful reply.  I think I understand the bit about how the bulb function.  The Cobalts are a mix of old and new: old controlled by ADFX the new ones with built in electronics.  The track is Peco: mix of fixed length Setrack and flexi, the points are Streamline - all code 100.  Most are electrofrog, I have not messed about with them to "DCC" them or done any frog polarity switching.  The Cobalts are simply fed with two wires from a separate bus, no extra wiring, no use of "clever" switches.  So I still don't understand the huge power demand on the accessory bus - presumably by the Cobalts.  Any help/advice/explanation on that greatfully received.

Edited July 17, 2018 by imt

[WIMorrison]

i have just looked up the stall current of the Cobalt Digital IP Motor which DCC Concepts state is 20mA stall at 12v and 16mA when changing. This means you would need to have 50 stalling at the same time to draw the 1 amp your bulb needs to light up, or 62 all changing at the same time. The static load is <5mA per motor which means 200+ to draw 1 amp - that is an awful lot of point motors

 

Now I don't know how many motors you have but as you are running the layout on a NCE Powercab I feel it may not be that many, which would suggest that blaming the Cobalt motors may be a mistake and that the fault lies elsewhere?

 

For comparison my static load is 420mA and this is caused by 25 Digital IP Motors and 8 locos with one loco drawing almost 150mA because it has incandescent bulbs (they are changing to LED at the weekend).

 

 

EDIT - I have just tested the actual current draw on a Cobalt IP Stall motor and I found that the switching current was 30mA and the stall current was 45mA - higher than they state but still not significant.

Edited July 18, 2018 by WIMorrison

[Mallard60022]

Thank you for your thoughtful reply.  I think I understand the bit about how the bulb function.  The Cobalts are a mix of old and new: old controlled by ADFX the new ones with built in electronics.  The track is Peco: mix of fixed length Setrack and flexi, the points are Streamline - all code 100.  Most are electrofrog, I have not messed about with them to "DCC" them or done any frog polarity switching.  The Cobalts are simply fed with two wires from a separate bus, no extra wiring, no use of "clever" switches.  So I still don't understand the huge power demand on the accessory bus - presumably by the Cobalts.  Any help/advice/explanation on that greatfully received.

Iain. You are not alone. Just last week something similar was being discussed about my layout. I was advised to go back to the Panel out put (NCE as yours) and work from there, testing power at track head after every adjustment/link up. I was also advised to comb the layout for shorts despite the fact it wasn't a short that was causing the problem as far as a friend  and I could see. Once, long before this, I had found that I had wired up something strangely which was sort of contra feeding between BUSES and that was causing problems; I have no idea how I cured that but I did! Another time I found a rogue track pin causing a problem and on another time a loco that was faulty that drew loads of volts.

I really think the going back to the start of the accessory power supply and working outwards might help? Could there be some sort of contra flow between the point motors and the BUSes?

Oh yes, I did find a point that I had not used an IRJ on at the heel (of one of the stock rails). I was advised long ago by a very wise and experienced modeller, to use IRJs every where and power every section of track (droppers). That has worked for me in the main but I have cheated on some long straight sections and relied on rail joiners (but with unattached droppers ready just in case) .

If you want to try a power supply with a bit more oomph, I have the NCE 13.8V @ 1.8A if you would like to borrow it?

Phil

Edited July 18, 2018 by Mallard60022

[imt]

i have just looked up the stall current of the Cobalt Digital IP Motor which DCC Concepts state is 20mA stall at 12v and 16mA when changing. This means you would need to have 50 stalling at the same time to draw the 1 amp your bulb needs to light up, or 62 all changing at the same time. The static load is <5mA per motor which means 200+ to draw 1 amp - that is an awful lot of point motors

 

Now I don't know how many motors you have but as you are running the layout on a NCE Powercab I feel it may not be that many, which would suggest that blaming the Cobalt motors may be a mistake and that the fault lies elsewhere?

 

For comparison my static load is 420mA and this is caused by 25 Digital IP Motors and 8 locos with one loco drawing almost 150mA because it has incandescent bulbs (they are changing to LED at the weekend).

 

Thank you very much for continuing to help. As Nigel Cliffe has pointed out - though I have 4 separate "power districts" the total power supplied by the PowerCab is 1 amp - so exceeding that on all 4 legs will trip the Power Cab itself.  This DOES NOT HAPPEN.

 

As I have said all accessories are on a separate feed which is not connected to any track at all.  I would assume therefore that (though the overall load may affect the PowerCab) what is on the layout does NOT affect the accessories bus.

 

The accessories bus feeds round the whole layout - about 18 feet max. I would think.  There are 5 TrainTronic signals, 6 GPLS, 13 Cobalts (maybe thats the problem! perhaps I should buy another?) and a bridge rectifier feeding a minor DC current to an IR detector. That's it.

 

As I have said, I have a control system which can issue multiple DCC commands to the bus and when that happens the sounds of moving Cobalts are accompanied by the glowing of the appropriate CP6 light.  I can get the same effect if I disconnect (and so discount the conrol box) and use the PowerCab handset.  Single commands can set a point or in some cases a crossover (2 points), I have a PowerCab macro which resets all main points to "normal" - which at the ultimate can fire off 10 Cobalts if they were all in the wrong setting (most unlikely).  The glowing of the CP6 light appears to be proportional to the number of Cobalts that move position. This can be over quite a long period as commands go out from the handset serially but the Cobalts may take a second to fully throw, so there may be several moving at once.

 

Does that help or confuse the issue further?

Edited July 18, 2018 by imt

[WIMorrison]

It suggests to me that you are towards the limit of available powerr on your accessory bus, and potentially towards the top end on your available power from the Powercab. The power availability of your accessory bus is being limited by the bulb, as suggested by Nigel, and if the movement of a cobalt motor at between 20-30mA change current, is sufficient to cause the bulb to glow then you are at the limit and need to consider the items being used on it - or accept that the bulb glows (glowing is a somewhat relative term though, you could be anywhere on a large range of current draw). I would be tempted to put an ammeter in the circuit to find what the actual total current draw is, and also measure the individual busses and items to see where the excessive draw is.

 

The other option is to get a commend system that can deliver the current capacity that you are using.

[RedgateModels]

MERG District Cutout boards work great with the Powercab (OK I am biased as I helped develop the prototype) I fit one to each 2 x 4 board on my exhibition layouts The feed from the DC06 goes to the track bus, any accessories are fed directly from the powercab. This separates track from accessories, allowing points to be changed if I run a loco into an incorrectly set turnout and a short on one board does not affect the others.

 

Very easy kits to put together with basic soldering skills, about 11 quid a throw, well worth a year's membership to stock up IMHO

[imt]

It suggests to me that you are towards the limit of available powerr on your accessory bus, and potentially towards the top end on your available power from the Powercab. The power availability of your accessory bus is being limited by the bulb, as suggested by Nigel, and if the movement of a cobalt motor at between 20-30mA change current, is sufficient to cause the bulb to glow then you are at the limit and need to consider the items being used on it - or accept that the bulb glows (glowing is a somewhat relative term though, you could be anywhere on a large range of current draw). I would be tempted to put an ammeter in the circuit to find what the actual total current draw is, and also measure the individual busses and items to see where the excessive draw is.

 

The other option is to get a commend system that can deliver the current capacity that you are using.

 

Thank you for your thoughts.  I accept your theory - but I don't see it borne out in practice.

 

Just for the hell of it I have disconnected the other three power districts AFTER the CP6.  I have checked that there is no power on ANY part of the track.  I have disconnected my controlling NCE Mini-panels.  I have disconnected the corner and fiddle yard boards from the station & port boards - physically and unplugged their cabling.  I have disconnected the bridge rectifier and the IRDOT from the accessory bus "just in case" (easy to do by removing one wire).  The only items connected to the PowerCab are on the only bus left connected - placing a loco on the track has no response because there is no power.  The final accessory bus has 10 Cobalts and 10 signals ONLY (the missing small number are on the disconnected boards (3 Cobalts and one signal).

 

Sadly sending commands to this tiny load results in the bulb glowing.  If I deliberately send some commands to set the main points to reverse and then use the reset macro which will sequentially (but without pause) sends "set normal" commands to the Cobalts then the bulb glows brightly for several seconds as the motors whirr. The interesting thing (to me) is that ALL the points are returned to normal, none get missed.  The "overload" does not confuse or lose the DCC commands.

 

Sadly I don't have an RMS meter suitable for checking things (nor the budget to buy such an expensive thing) and I doubt if my best Maplins analogue unit will get anything worth reporting.  The standard load is 10 micro LEDs and their controllers and 10 * 5mA for the Cobalts.  Even if I fired all 10 Cobalts simultaneously then the draw should be 10 * 30mA  which (as you say) should be insignificant. I doubt if the whole shooting match exceeds .05A let alone the .5A which should be necessary to set the bulb off.

 

I understand what both Nigel and you have said - but I don't see how it applies.

[imt]

Iain. You are not alone. Just last week something similar was being discussed about my layout. I was advised to go back to the Panel out put (NCE as yours) and work from there, testing power at track head after every adjustment/link up. I was also advised to comb the layout for shorts despite the fact it wasn't a short that was causing the problem as far as a friend  and I could see. Once, long before this, I had found that I had wired up something strangely which was sort of contra feeding between BUSES and that was causing problems; I have no idea how I cured that but I did! Another time I found a rogue track pin causing a problem and on another time a loco that was faulty that drew loads of volts.

I really think the going back to the start of the accessory power supply and working outwards might help? Could there be some sort of contra flow between the point motors and the BUSes?

Oh yes, I did find a point that I had not used an IRJ on at the heel (of one of the stock rails). I was advised long ago by a very wise and experienced modeller, to use IRJs every where and power every section of track (droppers). That has worked for me in the main but I have cheated on some long straight sections and relied on rail joiners (but with unattached droppers ready just in case) .

If you want to try a power supply with a bit more oomph, I have the NCE 13.8V @ 1.8A if you would like to borrow it?

Phil

 

Thank you for all of that.  I have had similar troubles myself when trying to sort out power districts.  Sadly we only learn (mainly from our own) mistakes.  I think the insulating rail joiners advice would have been good for me too.  However that does not apply in this particular case, since the accessory bus is separate from the track buses.  Thanks for the offer of a loan of a heavier duty power supply, but I don't think that is my problem.  I'll keep in touch on that.

[WIMorrison]

10*Cobalts @ 30mA= 300mA, 10*LEDs @ 20mA = 200mA which is a total of 500mA or 1/2 Amp, which will get your bulb glowing nicely, your standing load is 250mA which is on the bottom end of lamp being obviously lit and in a dark corner you might see it, but add in a Cobalt or two and I would expect to see you see it starting to light clearly. (We used to use lamps dim when paralleling generator phases as it is remarkably easy to see when a lamp is just starting to light up therefore out of phase (and it doesn't take much current))

 

The numbers all add up, and if you are running several locos at the same time you are getting close to the 1 amp capacity of the Powercab, as you need also to consider the standing load of the locos when they are on the track, especially when they have LEDs - not a lot for each one, but it soon adds up, especially in larger gauges e.g. 00/h0 where the current draw is higher.

 

BTW - True RMS meters can be bought for £15 now

Edited July 18, 2018 by WIMorrison

[imt]

10*Cobalts @ 30mA= 300mA, 10*LEDs @ 20mA = 200mA which is a total of 500mA or 1/2 Amp, which will get your bulb glowing nicely, your standing load is 250mA which is on the bottom end of lamp being obviously lit and in a dark corner you might see it, but add in a Cobalt or two and I would expect to see you see it starting to light clearly. (We used to use lamps dim when paralleling generator phases as it is remarkably easy to see when a lamp is just starting to light up therefore out of phase (and it doesn't take much current))

 

The numbers all add up, and if you are running several locos at the same time you are getting close to the 1 amp capacity of the Powercab, as you need also to consider the standing load of the locos when they are on the track, especially when they have LEDs - not a lot for each one, but it soon adds up, especially in larger gauges e.g. 00/h0 where the current draw is higher.

 

BTW - True RMS meters can be bought for £15 now

 

Thank you for bearing with me!  I obviously failed to move decimal points appropriately or to add the results properly.  Ugh!  Sorry.

 

I now see what you are saying.  Is this situation OK - can I continue like this - or do I need to revise my whole layout powering ideas?  If so how - cost IS a problem. |What do I do with my CP6? Careful this is a family show!

 

My age is showing! RMS meters for £15!!!!!  Strewth at that rate worth waiting for even if it does have to be shipped from China.

 

Thanks again!

[BromsMods]

 

The numbers all add up, and if you are running several locos at the same time you are getting close to the 1 amp capacity of the Powercab,

 

Where on earth do you get this information?  The limit of the PowerCab is 2 amps.  You can monitor the current usage on the handset (SET CAB PARAMETERS - SHOW TRACK CURRENT - PRESS 1 for YES) so you can track the current draw for any accessory attached to the bus.  As far as short circuit protection is concerned I would never recommend the CP6 as this was only a stop-gap measure when it was found that the EB3/EB1 were not suitable for use with the PowerCab and, as said previously, it does not provide true protection from short circuits - use a DCC Specialties PSX1 (or preferably a PSX2 to separate loco and accessory buses, then if you have a short circuit on the accessory bus you can still operate locos, or vice versa).  The PSX range also allows a trip value suitable for protecting the Powercab to be set.

[Mallard60022]

Where on earth do you get this information?  The limit of the PowerCab is 2 amps.  You can monitor the current usage on the handset (SET CAB PARAMETERS - SHOW TRACK CURRENT - PRESS 1 for YES) so you can track the current draw for any accessory attached to the bus.  As far as short circuit protection is concerned I would never recommend the CP6 as this was only a stop-gap measure when it was found that the EB3/EB1 were not suitable for use with the PowerCab and, as said previously, it does not provide true protection from short circuits - use a DCC Specialties PSX1 (or preferably a PSX2 to separate loco and accessory buses, then if you have a short circuit on the accessory bus you can still operate locos, or vice versa).  The PSX range also allows a trip value suitable for protecting the Powercab to be set.

Dammit John, I wish you were still trading.........

Sincerely

Phil

[imt]

Where on earth do you get this information?  The limit of the PowerCab is 2 amps.  You can monitor the current usage on the handset (SET CAB PARAMETERS - SHOW TRACK CURRENT - PRESS 1 for YES) so you can track the current draw for any accessory attached to the bus.  As far as short circuit protection is concerned I would never recommend the CP6 as this was only a stop-gap measure when it was found that the EB3/EB1 were not suitable for use with the PowerCab and, as said previously, it does not provide true protection from short circuits - use a DCC Specialties PSX1 (or preferably a PSX2 to separate loco and accessory buses, then if you have a short circuit on the accessory bus you can still operate locos, or vice versa).  The PSX range also allows a trip value suitable for protecting the Powercab to be set.

 

Thank you for your help.  I have checked the manual and it does indeed say 2 amps.  Sorry I should have read more carefully.  I have also switched the ammeter on (if all else fails read the operating instructions!).  I have a background at my reduced level (described in post #17) of 0.16 amps.  Changing a crossover sees the draw go up at peak to 0.42 (so much for 30 milliamps!). Causing the reset macro to run as described above (multiple Cobalts fired one after the other) I get a max reading of 0.8 amps and a beautifully lit bulb. So the explanation is clear.  

 

Adding most of the rest of the load, including my 2 NCE Mini-panels gets me up to a background 0.34 amps.  Strangely the peak firing loads are 0.54 for a crossover but the maximum of 0.8 for the macro doesn't seem to change(??).

 

Sadly I cannot afford the PSX range.  I have 4 separate busses and the cost is eyewatering.

 

Any advice at affordable levels would be very gratefully received - with apologies for wasting so many people's time.

[WIMorrison]

Where on earth do you get this information?  The limit of the PowerCab is 2 amps.  You can monitor the current usage on the handset (SET CAB PARAMETERS - SHOW TRACK CURRENT - PRESS 1 for YES) so you can track the current draw for any accessory attached to the bus.  As far as short circuit protection is concerned I would never recommend the CP6 as this was only a stop-gap measure when it was found that the EB3/EB1 were not suitable for use with the PowerCab and, as said previously, it does not provide true protection from short circuits - use a DCC Specialties PSX1 (or preferably a PSX2 to separate loco and accessory buses, then if you have a short circuit on the accessory bus you can still operate locos, or vice versa).  The PSX range also allows a trip value suitable for protecting the Powercab to be set.

 

Mea culpa, I thought that this thread was suggesting it is a 1A output, however as you state it is 2A I will happily be corrected

 

That doesn't however change the discussions about the lamp glowing on the accessory bus which it will do due to the current draw, and due to your timely intervention the OP now knows he can do and he can see what current is actually being drawn. I would also heartily agree with changing to the PSX circuit breaker, I originally suggested the NCE EB1 unaware of its limitations with the Powercab

[WIMorrison]

…

I have a background at my reduced level (described in post #17) of 0.16 amps.  Changing a crossover sees the draw go up at peak to 0.42 (so much for 30 milliamps!). Causing the reset macro to run as described above (multiple Cobalts fired one after the other) I get a max reading of 0.8 amps and a beautifully lit bulb.

...

 

Which Cobalts are you using? I have again checked my IP Digital motors and the figures I quote earlier are still what I see (30mA changing and 45mA stall), yet you are stating that your current draw is 10 times what I am seeing