Hi all,

So I started experiencing an odd problem yesterday whereby my trains would drive for maybe a minute and then stop.
It would give me this error on the CS2:



It means power overload. This is not uncommon because I often get quick short circuits due to pickup shoes on turnouts etc. randomly - very annoying though I have fixed most of them.

However the above was happening regardless of the trains driving, even when stopped.

I suspected some sort of track short circuit etc. but long story short I think it is just my CS2/PSU being overloaded from too many trains.
You see I had recently added a new storage yard which has been fine but I think after an additional 1 or 2 locos being added to the storage yard I am now at my power limits.

CS2 with main track disconnected, all OK 22v:



With the main track (everything) connected:



I then tested by isolating my new storage yard:



With half the storage yard disconnected



So I reconnect my storage yard and turn off all the loco headlights (I normally leave headlights on but all other functions off)



In any case I am confident there is no high resistance short circuit on my layout.

What I find interesting is that I have a 60VA transformer and yet my CS2 only shows 2.5-2.8A of current draw at around 16V. This is only at most 45VA. I would have expected it to cope.

The question is where to from here. I don't want to have to wire in a booster. I can either buy an Ecos2 with 7amp PSU or buy a newer PSU to replace my 60VA transformer.

For reference this is my transformer. Not sure on model number and it's too hard to remove:



Given the CS2 still shows current draw in the green, I think its definitely just my 60VA not coping.

You can see I have CS2 version 60215 though it is the older 4.3 hardware.

Moving forward I should be able to use either item #60043 or even better #60101 (100VA) or the older #60061.

And yes I realize hardware revision 4.3 does not support using 100VA but it would still work and it would certainly solve the PSU being a limiting factor and prevent voltage drop, though the extra cost may be a waste.

What are your thoughts and do you know what PSU I currently have? Guessing its a transformer.

Edited by user 14 November 2020 12:29:54(UTC)  | Reason: Not specified

FWIW I dug out some measurements I made some time ago
(These were dummy - purely resistive loads)

I do see that the data point where voltage dropped to 16V was close to
- 3.75 A -as per CS2 display
- 4.25 A lamping the actual feed

At 2.8 (as per CS2 display) which equated to 3.2 as measured from the transformer, The voltage was still @ 17.8

So, unless your household wiring / street power voltage is low, it may be that the transformer is stressed.
(Do not neglect the feed from the wall socket - under rated extension cords, cheap multi-boxes may play are part)

Noting that for transformer circuits a cheap way to detect power draw was to sense the voltage drop rather than the actual current.

Thanks Peter for all your help and testing notes. Do you have any experience testing with the new #60043/60041? ie. can it hold ~19V at 3.3amps?

Hi Applor
A transformer to feed a CS2 is not ideal (no stable rectified voltage which should be 19 VDC). The result is fluctuating speed in locos even when with regulated MFX decoders
On my layout, I have an unorthodox solution: a 60101 (100W regulated power supply).
I know Märklin pushes for the use of 60061 (60W PSU) but in my case it works very well since 8 years and provides 5A instead of 3 A.

There are 2 reasons for Märklin's advice:
- all signals are rated for 2A (so a short with 5A could destroy the signals contact: Not in my case because I use Rocrail and have not a single one stop section.
- the fear of legal consequences in case of fire due to undersized wires: not in my case as I use a 2.5 mm² power loop and 0.75mm² for small connections


Because of the current fluctuations, a safe operation is only possible when you have a 20% to 30% power reserve.
Example: my layout with 32 locos, illuminated trains, 70 track devices draw a current of 2,8 A. If I program my CS2 to a 60061 (60W 3 A) then rapidly, the CS2 detects an overload just as you did even with Rocrail (only one solenoid activated at any one time).
These are my 2 cents worth
Jean

Hi Applor

"From what I have read though the bigger issue with the 5amp 60101 supply is in the case of a short circuit between say pickup shoe and rail, you have a lot more peak current through that short than with a 3amp supply, which can damage the pickup and/or rail.
With 1 gauge the rails are far thick so a short circuit won't damage the track before overload kicks in."

In fact the CS2 has a very clever over current detection: as soon as a current over the limit is reached, the unit switch the current off but only for a short while and it samples if the over current is confirmed. The result is:
- never did I have a damage due to over-current (switch blades, contacts, mini welding, loco failure / decoder destruction, etc)
- the protection is not only effective but it does not over-react

So in short I am very enthusiast about this solution.
It save for me one Booster + its own power supply= more than 200€ (German rebate prices)
No problem in sharing the power in the layout (Power is never on the side you want)
complications in wiring
I had one of the first 100W PSU so it is more than 8 years ago with an intensive use of my layout.
Cheers
Jean