Hi!
Why are both rails isolated? Is this required by your booster manufacturer?
I can imagine that this is the root of the problem.
Maybe just bridge the outer rails when the train stops to see if it will carry on (unless bridging is forbidden by the booster company).

So the Märklin RAm cannot work in reverse direction when you follow Märklin's guidelines.

How many trains will be running at the same time? Do you really need that many boosters?

The left/right splitting is part of the problem as trains often pass between left and right.

An inner/outer splitting for the double isolation would reduce transitions of trains across the double isolation.

A different approach would be changing the wiring inside the RAm. It seems to use the centre-rail on the control car, but the outer-rail on the motor unit. This makes it stop on your isolated spot.
You may encounter the same issue with other trains that have two sliders for push/pull operation.

The 39706 is designed to switch power source so that the power comes from the leading slider depending on the direction that the trainset is travelling.
I do not know if this includes all functions (lighting) or whether lighting is still powered from the slider at the rear of the train.
I also do not know whether all power connections are via the current conducting coupler or whether each bogie still serves as ground (return) for that coach.

If we assume that all power is collected from the leading slider and that the return is also connected via the PC board and couplers, then there should be no issues affecting the power supply.
If like the older 3471/3071, the power is collected from the leading slider, but the lights are powered by the trailing slider, then there maybe some instances where the train is receiving power from two sections. If there is some bleed over from lights to motor, this may cause some issues.

It has been a while since I have seen a Maerklin model where the instructions include a wiring diagram. Normally, the instructions include basic instructions and an exploded diagram.
I don't recall seeing any documentation which identifies what current is transmitted by which contact via the couplings.

The problem may be that the trainset is trying to collect power from the lead slider (in this case, the pilot coach), which is in one booster section, but the powerhead (motor) is connected to the ground/return in another booster section and the voltage loop is not completed, as the returns are not interconnected.

I would suggest that the solution may be to connect the live from each booster to the centre rails of each section, using separators between each section. The return wires should go from the boosters to a common terminal, which would then be connected to each section. As long as the boosters are all properly connected to the mains and are properly wired to ensure polarity, you should not have any issues.

Another solution would be to come up with a system where there is a neutral (switchable) section between each booster zone and the train would drive in powered by the section that it is leaving and the section would then switch over to the next booster once the last car tripped a sensor which would cut off power supply A and trigger power supply B for that zone. This way, the train would not straddle two zones at the same time.

Regards

Mike C

Hi Steve
The result of isolating both output (B and O) on each booster results in the RAm TEE stopping. Why?
Because the ground pick-up is in the loco (no switch-over there) while the slider of the rear is used because you run backwards.
So this is normal and the simple result of your improper wiring
I don't know which type of Boosters you are using. Definitely with Märklin 60175, only the center rail (stud) needs isolating.
There is NO risk of overload (adding all the current from each individual booster) by doing this.
The only recommended practice is to avoid stopping trains where the power feed changes (risk to connect both boosters in parallel) for a long period of time.
No slider rocker needed either

So don't touch your RAm, it is very fine. Update the wiring
Cheers
Jean

Hello
As Tom pointed before, with only 3 trains running at any given time, 10 Boosters seems like an excess to me. You will need plenty of feeders to ensure power distribution, but not so many booster, i think
Regardsd

Let me clarify a bit more.
Boosters are Marklin 60174 all powered by the 60061 switch mode power supplies. I don’t use the CS 3 for powering the layout. ( although I do use the CS3 to power a separate DCC tram system). The track design is a central terminal station which feeds into a large double track on a U shape baseboard at a number of different elevations. Given the layout size , it was designed with movability in mind for future relocation.
The return earth wire is heavy duty and is rated to handle up to 20 Amps ( Each red power feed is rated at 7 amps)The aim was to run around 15-20 trains via timetabling with no more than 3 trains in any given booster section. Each of the 10 boosters have their respective power feeds isolated from each other and then further divided the layout into 2 separate earth sections ( left and right by isolating both outer rails).This allows me to keep the earth potential below Marklin’s recommended 300VA for each side of the layout.
I should also point out that I have 4 more boosters powering just accessories as I have over 150 decoders used for control of animation using WDP software. Obviously these are not connected to the track system but via the CAN bus.
By bridging the earth return of right and left sides the RAm works in both directions, removing the bridge wire causes the RAm to stall at the isolated transition point while driving in the reverse direction only.
So do I keep the bridge wire in place , but increase the power rating well above Marklins recommendation.? Or reduce the booster and train count to bring it down to under the 300VA threshold.
. I wonder how big layouts handle this issue.? I don’t believe wiring of the boosters is a problem. I think it is more to do with these double slider car sets and how they treat two separate earth points.

Thanks Tom. After reviewing my designed I was able to remove a couple more boosters without effecting my operation to much. I completed some extensive testing last night , with a number of trains running and booster monitoring, all appeared to work without a glitch. The loading at each booster appears to be well within spec , so will leave my bridge in for now. So far so good..!
Now I have a complete loop up and running (after 7 years of building.!) I have become sidetracked with running trains instead of building the layout....My delight of running a loco or two got the better of me after all these years instead of just back and forward testing. But so did the time .... I had to crept into bed at 2.45am and try not to wake my wife, then get up at seven and pretend nothing had happen..!!!!!