Heavy 4-8-2 in DC mode

[in_eden]

I received a replacement heavy 4-8-2 today, as my initial loco "melted down" running DC. I had read that this DCC equiped loco would run on a standard DC layout without problem... but after about a week, the loco started stuttering, there was an all-to-realistic smoke in the air smell, and the tender deck melted!
Was this an isolated incident, or a result of running a DCC loco on DC track?
I'm a little nervous about repeating the meltdown!
Any one know?

[TCWORLD]

only thing i can think of is, is the DC voltage way to high.

[the Bach-man]

Dear Eden
Your loco should run right out of the box. I agree: check your voltage, and make sure you're using DC, not AC.
Have fun!
the Bach-man

[in_eden]

I it's definately on DC. I've got a nice assortment of Proto, Micro-trains, Intermountian, Model Power, Atlas, as well as Spectrum J, 2-8-0, and Mallet that all run beautifully. This was the first DCC equipped loco I've purchased, and it failed! So, I thought I should check and make sure I didn't have to disconnect the decoder or bypass it in some way to prevent an overload.
Should the loco draw more volts than the others in normal operation? It seemed that the throttle had to be 15% higher than any other loco I've got... maybe there was a wiring flaw to begin with?
I dunno. I just didn't want to blow up another one!
thanks.

[taz-of-boyds]

In_eden,

A DCC loco on DC will have a higher start voltage than a DC loco, this is normal.  Why?  Because the DCC decoder is still in control of the motor.  And the decoder needs enough voltage to start operating before it can start controlling the motor.  If you can check the voltage output of your controller while running the DCC loco, you might check to make sure the voltage does not go much over 14 volts.

The generic Bachmann DC controllers I have produce well over this if turned up all the way.  In theory the motors in N scale are max 12 volts for safe operation.

For your specific meltdown problem, there may be other issues if your DC controller does not provide a clean smooth DC voltage.  These problems can exist even if the DC locos work just fine.

Charles

[brokemoto]

Both of mine run well on MRC 2400.  I keep the pulse switch in the OFF position.  There are those who have asserted that if you run a 'smart' decoder on pulsed DC, there are problems.  I tried one of mine on the 2400 with the pulse ON, and there were no problems and no heating.