Rebuilding Märklin 28452, DH 360 Ca, to digital with Märklin conversion set 60760
This can be done on many other models based on the Märklin 3078, DHG 500 and the Märklin 3088 DHG 700.
For this locomotive type with Small Flat Collector Motor (SFCM), see 3044

Updated 22.01.2014

The Märklin 28452 set:

The Märklin set was made by Märklin in 1999 and 2000 for Holland, with three different cars.

Why rebuild a Delta locomotive?
Why rebuild it, as it already has a Delta decoder, which enables digital operation?
Six, for me, good reasons:
1. The new decoder is adjustable, so I may achieve the prototypical correct max. speed, which is 60 km/h.
2. The acceleration and braking delay is also adjustable.
3. The new 5-pole motor runs very smoothly.
4. If using a braking module at a red light, the locomotive will come to a slow stop in front of the red light
5. Possibility to switch the light on and off, as well as the light may be on while the locomotive is stationary.
6. Possibility for internal light.


Märklin 28452-1, DH 360 Ca

I think this is the only 3078-based locomotive from Märklin with connecting rods.

The locomotive inside before disassembling:

Very simple to explain: remove everything.  After removing the pick-up shoe, unsolder the small contact plate.  Unscrew the two screws on the motor cover and the decoder from it's holder.  Then it should be possible to "lift out" the reversing unit and the motor in "one piece".  I carefully pack these parts in a small plastic bag and store them.  Remove the decoder holder.
I removed the "axel covers", not to damage them.

The pick-up shoe and it's contact plate, the motor screws, the soldering lug and the brushes will be re-used.

The disassembled locomotive:

I kept the wires from the bulb sockets, as they are difficult to access under the locomotive.  The yellow, grey and front brown wires were soldered directly to the new decoder.  The rear brown wire was soldered to the interior light's orange wire.  See wiring diagram below.

Conversion parts:
For the 28452 the conversion sets 6090, 60901, 60921 or 60760 may be used, or the new motor set 60941, as the motors in these sets are identical.
If using the 60941 motor set, a separate decoder set, for instance the mLD (märklin Lok Decoder) 60962, may be used.

In this case I used the decoder is from a 60760 conversion set, installed where the Delta decoder used to be.  It is supposed to be installed in the holder 456200, but I had none left in my box, so I have to order more from my Märklin dealer.
This decoder gives 14 speed steps, which I find more than enough for the prototypical top speed, 60 km/h.
The 60760 decoder is rather simple, but I selected this decoder for it's adjustability, especially the top speed.  I had the decoder in stock from an earlier conversion.

Installation of the motor itself is not difficult.  After removing all the existing parts (motors, reversing unit, bulbs etc.), clean the chassis and make sure that everything (transmission and wheels etc.) is turning smoothly.
Install the new motor to the locomotive, firstly without the brushes. Check once more that everything revolves freely. Install the brushes.

The new locomotive inside:

Decoder holder 456200 is missing, so I have to buy some more.

Interior light:
Small yellow smd LEDs were glued to both sides of the "tower" for the body screw, over the motor.  An orange wire form the decoder was soldered to the cathode of the front LED, the brown/red wire to the anode of the rear LED.
A 680 Ohm resistor was soldered between the rear cathode and the front anode.

Photo from Märklin 3044, Henshel EA 800

Front and rear light:
The 28452 locomotive had a 610040 bulb in each end, in bulb sockets.  I replaced these with bulbs 610080, to cope with the higher voltage from the 60760 decoder.
I kept the original wires soldered to the sockets, as it's not so easy to access the bulb socket from below with a soldering iron.
The wires were soldered directly to the decoder.

This photo shows the new front lamp:

Anti Alzheimer:
The 60760 decoder was known for one "bad" thing; to forgets it's previous speed, even after a short power loss, and restarts the acceleration from zero.  This is often referred to as the 60760 Alzheimer effect.  his may have been early production only, as I have only experienced the phenomena on one very early (2005) production decoder.
To avoid this, make a "back-up" power supply, which gives a short time power supply to the memory circuit in the decoder. I installed a small capacitor and a resistor, connected to the decoder.
See above photo and below wiring diagram.

It is installed in this locomotive as a precaution and for fun, as I had the parts laying around.

The 60760 decoder:
This photo shows the 60760 decoder, with some additional wiring.
On top:
no. 3 from right - a brown/red wire for the "secret" f3 output, used for the interior light
no. 4 from right - an additional orange wire, with + for the functions

On the bottom:
A purple wire to the minus end of the capacitor
A black wire to the resistor.

I see from the detailed photo that some of the soldering must be re-done.

Wiring diagram for the 28452 locomotive:

Part list for the conversion:
Part number Pcs. Description
60760 1 Conversion set for locomotives with 5-pole drum collector motor
456200 1 Holder for decoder
610080 2 Bulbs (22 Volt)
- 2 smd LED, yellow For the
interior light
- 1 680 Ohm resistor
- 1 10 Kohm resistor For the
"Anti Alzheimer"
circuit board
- 1 1000 uF 6,3 Volt capacitor
- 1 Home made experimental circuit board, 3 rows, 6 holes

Screenshot from Central Station 1:

Märklin 28452 Henschel DH 360 in the dark:

Some external links: obout DH 360