DCC circuit breakers

[Hippo]

 Hi all,

I have a Gaugemaster prodigy advance and 5 amp booster and I would like to split them up into 4 power districts.

I thinking I will use the base unit for 1 district, and the booster for 3 districts.

I have read stuff about using circuit breakers and most people seem to recomend the powershield, but are there any others ? I have been thinking about joining Merg for a while, do they make a   kit ?

 

Thanks in advance for the advice

 

Owen

 

 

 

 

 

[Oldddudders]

Whichever system you use, the key feature you need is that it should cut out faster than the trip in your command station - otherwise your 4 power districts effectively just become one layout again.

[Izzy]

I tried using a PSX-1 with my Prodigy PA² system and it wrecked the base station, which Gaugemaster had to repair, so beware. I don't know if the MERG unit is compatible, I haven't tried, and am wary of doing so since no reason could be found as to why the PSX was incompatible (Powershield twice sent units direct from the USA which still wouldn't work with it and couldn't figure it out).

 

I believe MRC actually make breaker units themselves for the Prodigy system but I don't think Gaugemaster stock/sell them in the UK.

 

Izzy

[Neal Ball]

Sounds like a case of bad luck... I too have a Prodigy and also have used 2 of the PSX-1 on the old layout and will use them on the new one as well...

[Brian]

Hi

MERG do indeed make a circuit breaker kit for DCC use Item number 57, cost to members £10.00. It provides user selectable trip currents of 1.5Amp or 3.0Amp plus selectable trip delay for use with Reverse Loop Modules.

 

The failure of the PA when used with an additional circuit breaker would seem to me to be most likely not to be due to the circuit breakers use, but more so to do with the PA itself being defective internally.

Whether a CB is used or not the PA should trip its output upon detecting any over current loading above it threshold thats applied to its terminals. If the CB doesn't trip the main console should upon the overload current / voltage drop reaching the overload threshold set by the DCC system.

[Nigelcliffe]

The MERG kit can also be built for 0.75A and 1.5A settable on the jumpers by putting two turns through the current sensing coil, the lower figures being useful for N and other smaller scales.  I used two turns when performing one of the test builds of the kit. 

 

- Nigel

[Phil S]

Personally I would consider splitting the Outputs as follows:  Original Base Unit (Gaugemaster/Prodigy in this case) for the ACCESSORY BUS.

Then use the BOOSTER OUTPUT(S) for the TRACK divided into (sub) Power Districts - each protected with  (in my case, PS-X intelligent circuit breakers /Auto reverse version as required)

The advantage of using the BASE unit ONLY for the Accessories, is that these are unlikely to experience a Short Circuit, whilst the Track (via the BOOSTER and PS-X's are)

So, while the track is short circuited from having run over a set of points left the wrong way, and the track power cuts, the BASE UNIT can still control changing the points, to clear the problem ... the PS-X then automatically resets and operation continues.

 

Note that devices like the PSX can be set for different 'workloads', and that the 'Coin Test' of Track Short Circuit protection should always be made to ensure that (when a coin or similar metal consuctor shorts the track at ANY part of the layout), sufficient protection takes place to CUT OFF the current flow ... whils still allowing the maximum (expected) current  to be taken without triggering protection.... ie With a 5A booster, and 00, that is several trains running in 1 section ..and a trip current of maybe 7A, but divided up with PSXs for sub-districts, each might be limited to 2A, with an overela limit from the Booster, of 5A.

 

By way of example - my loft layout uses 4 Roco Amplifier/Boosters (powered from 4 separate SMPS 18V dc supplies), and these split the layout into 4 districts. The quiescent current fom standing locos and coach lighting and sound etc is anything upto about 1A (mainly in the storage district). Actually running a loco adds 0.5-1A for modern locos in each section ... this can be monitored as they go round as each district has its own RRampmeter measuring and displaying the current. 

The accessories are controlled from the Master Amplifier - without a PSX.

[Crewlisle]

Can someone answer my questions in plain English instead of the complicated gobbleydegook in the official instructions? They frighten me to death & make it look that if I fitted two PX-1s to my DCC system I could mess it up completely!

 

I have just purchased two PSX-1 circuit breakers. My 2.6M x 2.3M 00 gauge DCC layout is on 3 interconnected levels – high level with terminus, mid level continuous run & low level reversing loop. I use a Lenz LZV100 v3.6 Command/Power Station, LK100 Reverse Loop Module on the reversing loop & three LH90 v3.6 hand controllers which plug in various positions around the layout. Currently I have just the single track bus for the whole layout so when I get a short the whole layout shuts down. This is a bit of an embarrassment at exhibitions like the NEC! That is why I want to split it into two power districts with two PSX-1s – one for the high level & one for the mid level + reversing loop.

 

The only items controlled from the track bus are the locos. I have no accessories with decoders & do not plan to use them. In the last 8 years I have been using DCC I have had no problems with the current installation & a stock of 47 locos. When I have a short on the layout the LH90 controller display flashes ‘Off’ in the data window. When the short has been fixed I just press the Emergency Stop button & control is restored.

 

I have read the instructions but would like to clarify a few items:

 

1. I am pleased to read that the PSX-1 is ready to be wired in & used without any further programming (Page 10, item B in the ‘Quick Start’ guide).

2. When using my hand controllers, I cannot see the command module so rely on the LH90s flashing to tell me there is a short. Currently no problem.

3. The instructions refer to LEDs to confirm a short on the PSX-1. The only location I can fit my PSX-1s is under the baseboard, ie out of sight.

4. I do not want to fit remote LEDs. Can I just rely on the LH-90 flashing ‘Off’ as before & just press the Emergency Stop when the short has been fixed to resume normal operation?

5. I will completely isolate the high level by cutting the tracks before installation of the new track bus & connecting the high level ‘droppers’ to it.

6. Will I have to do anything to my existing LK100 Reverse Loop Module on the reversing loop which I have adjusted for my locos which now all run without problems on the reversing loop?

7. I currently use one of the roads in my loco shed as a programming track (isolated with a DPDT switch) as not all my decoders allow Programming on Main.

8. When my PSX-1 is installed, will I be able to use this track as before?

9. Can someone explain what ‘Sequential programming instructions for setting the address & programming CVs’ on Page 12 of the instructions is & whether I would have to do anything in the simplistic & fault free way I want to run my DCC system?

 

I would be grateful for answers to questions 4, 6, 8 & 9. Thanks.

[Phil S]

Adding a 'remote LED' is probably best done by adding a 'Stop' Light to a buffer stop, or using a street light nearby, or any other visible place an indicator could benificially be placed - it only needs to tell you VISIBLY that there is no power on that part of the track!  Use an LED, 1N4148 diode, and 1-2k resistor, or ready made example. Children moving on a Viessmann Swing is used on one of our layouts! 

Although by not seeing the PSX you will miss seeing it repeatably trying to re-power the track. 

Ideally, with the PSXs in use, the Central Controller will NOT be cutting out at all, and therefore NOT flashing - DO NOT PRESS STOP or they will!

 

Perhaps because I used to teach people about maintaining equipment, in my case, my PSXs and RRampmeters are all paced in a visible location ...back by the (Roco Amplifier/Boosters) and their Central, manually switch-controlled isolation/allocation to power districts....

(This panel allows me to use just a single Amplifier/Power District for the WHOLE layout if I so want, or to substitute another Amplifier/booster if one is faulty or 'missing'. 

My switches also have, as a diagnostic, an associated LED on the TRACK side of the switch which CONFIRMS to me that there is power on that part of the track (and will show, for example, if it is 'switched off' BUT a metal wheel is bridging the gap between sections, making it live)

 

You could also consider changing to the PSX AR, as I have done; this is solid state, in preference to the older Lenz Reverser which will probably be responding more slowly, and may need current sensitivity adjustment between locos (depending on the variety of makes you use)

(There is a modern, but more expensive alternative which avoids the momentary short, by 'pre-detecting' with another short isolated section each end - from MAssoth, and aimed primarily at avoiding the high currents possible in a G Scale Short Circuit ...but the same principle CAN be applied to OO/H0 with opto detectors or similar)

 

The diagram below shows the 'central panel' for my layout which covers 8m x 5m on 1.5 levels, with 4 Power Districts: All control is from Maultimaus/MultimausPro handsets.

Each Amplifer/Booster also has a RRampmeter to show current and voltage being taken.  These feeds are then passed through the DPDT centre-off switches (shown by 'Hex Nuts' in the diagram), and the LED above each switch is on the Track/Accessory (output) side of its switch. The TOP ROW is TRACK, The middle row are Accessories (Including Points/Signals), and the bottom row is 16Vac power for Lenz LS150 decoders etc.  Not included here is the 12V 4A SMPS used for Lighting and any dc-powered modules on the layout.

 

NOTE the PGM track feed: THIS (which does form a part of my mainline - to be able to cope with Multiple Units) - does NOT go via a PSX !!

'Barnstaple (Junction)' is my main station - it has its own PSX, and is then LOCALLY isolatable into sub districts abc (platforms, sidings, etc)

'Left' and 'Right' refer to the scenic sub-district sections of the layout to the left and right of the central panel .... there was orignally a 'centre' area, but this has been merged.

'Exeter' and 'Termini' together form the lower, storage level of my layout -  6´+ (4 + 3 + 4) tracks  are locally split into sub-districts, including an auto-reverser section.

The GREEN BACKGROUND denotes the 'Normal' Power Switch Position:  from  MASTER  and  Boosters; B'staple, Scenic, Lower, the alternative being labelled in each case..

The '16Vac' is labelled as coming from a surplus ZTC transformer, but the alternative of a 12V Ikea Lamp Transformer is sufficient for our Roco point motors (and more portable!)

Note that Points/Signals for an area are normally controlled from a different source to the track.

Crane is ac power to a Roco DCC Crane Module

The warning about isolating ALL OTHER SECTIONS when programming applies ONLY IF a std Roco Amplifier is the Master, and not a Rocomotion/MultiCentralePro with Pgm o/p

'And finally' The 'high level' mentioned is a separate EYE level loop on the RSJs supporting the roof, and the finalYellow Master/Lower is now 'Spare'

 

I also use 3 different sleeve colours for the 6A twin flex I use to distribute the dcc signals, and 2 different colour 'high-current' loud speaker cables for ac and dc power runs.