Originally Posted by: mario54i 
Hello
Have you ever seen a rotor in these conditions ? It's an HAG Typ88 motor from a Re456.
What happened ? This engine was converted from DC to AC digital by a professional, he replaced all he could change, including the magnet (!!!). Tha bill was quite high but the result was poor, the loco was swinging on rails, he advised me to run it slow on turnouts. More than ten years later I decided to upgrade that loco with a new decoder and LED lights, and at first to get rid of the swinging. I removed the motor from chassis, connected to a power supply, forgot it was set to 12 V and I heard a "crack". Absorbed current went immediately to zero and that was the reason.
Yesterday I found a new rotor and I replaced the broken one. This time I was careful, power supply was set initially to zero and voltage increased slowly. The engine started at 2 V drawing 120 mA, running was regular just with a strange gear noise, some oil helped. I increased voltage slowly without problems up to 8 V, then the current dropped again to zero. Another rotor gone.
What has happened ? I converted other HAG AC motors to DC for digital and never had problems.
What's your advice ? Sending to factory ? I don't feel confident buying another rotor and trying again, it's 32 CHF each.
Thanks for your help
Regards
Mario
Mario,
a few quick questions…
1) What kind of decoder did you have installed?
2) Did the conversion include installation of AC wheelsets and wiring modification of slider/wheel contacts?
3) The design of the older Hag models has one of the poles conducted via the chassis. If the conversion is not properly wired and the decoder is not connected directly to the axle and centre rail contacts and the motor wired only directly to the decoder, this can cause a short between the motor and decoder. Normally, I would expect damage to the decoder, but if the rotor was the weak point, I could see that burning out too.
Before you buy another rotor, I would recommend that you have the locomotive tested to ensure that everything is ok.
I remember that D.O.C. models was at one point the distributor for HAG in Italy. I do not know if that is still the case.
I know that Hag has dealers in Ticino and in Valais (Sion), both near the Italian border.
You can also send to Hag in Switzerland. They can verify and repair as needed and maybe add new lighting circuit that would give you red or white taillights and other functions. I do not know if the new electronics fit in the Re 456.
If you need, I can send you a photo of the inside of one of my AC Re 456s so you can see how it is wired (Factory OEM ESU)
You can also contact Jacques Vuyes via the forum and see if he can assist and maybe Stefan Unholz can chime in too.
From the Hag website (Conversion):
"Der Motor muss bei alten AC Modellen mit einem Permanentmagneten ausgerüstet werden. Neuere AC Modelle mit Decoder haben diese Magnete bereits eingebaut.
Um Motoren mit Feldmagneten umzubauen muss auch die rot gekennzeichnete Schraube, welche sich unter der rechten Blechkappe befindet, herausgedreht und die darunter liegende Unterlagscheibe entfernt werden. Die Schraube wieder hineindrehen.
Beim Laufdrehgestell muss nun der richtige Schleifer montiert werden."
http://www.hag.ch/images...q/01-anschlussschema.jpgYou spoke of converting a DC model to AC, so I presume that it would already have had the Permanent magnet, so I don't understand why your conversion would have required a change of magnet. Is it possible that the wrong magnet was installed as a change would not have been necessary for a DC model?
If it was an AC model that was converted, you should also make sure that the issue with the red marked screw has been addressed, but I stand with my initial suspected diagnosis that the problem may be related to the grounding of the chassis and contact with the other pole via the motor housing.
Regards
Mike C
