So here is a question for the group. I am new to DCC (very new). I started with a MRC Prodigy Advance system. It worked very well for 4 locamotives I put in service, but seems to have fried a new XL Systems Decoder. In trouble shooting, it seems that the System is delivering 27.4 volts DC to the track. I doubled back through all the components and the output voltage out of the main system is 27.4 volts. I checked the output voltage of the Power Supply and it is all over the place and is not a steady voltage at all. All of the tags say that it should output 15 Volts. I contacted MRC, but have not heard back yet. Curious as to why this would work for 4 different decoders, but fry the fifth.
Welcome to the forum. I think there is still moderation for newbies so it will take a while for your response.
I don't know the MRC Prodigy, but 27 V for HO is too high. It should have fried all the decoders.
Henry
COB Potomac & Northern
Shenandoah Valley
Welcome to the forum.
How are you measuring the voltage? A DVOM will give you all kinds of readings. DCC is not DC or AC and will confuse any decent multi meter. To give you a general reading you need to put a load on the rails. I use an 1156 tail light bulb. This will calm down the spikes and dips that will drive your meter crazy. Set it to DC if it's available. Some meters are auto switching and will try reading it as AC voltage.
Decoders fry from a number of reasons. A fault in manufacturing, over loading the motor circuit, a shorted out lightbulb will fry the lighting circuit, and a shorted motor to frame will let the smoke out.
Pete.
the system is not delivering 27 DC volts to the track ... first of all, it's not DC voltage, it's DCC and should be measured with a DCC meter, and should read about 15-16 DCC volts ...this can be approximated with a bridge on the track, and measuring with an ordinary DC mutimeter, and adding for 1.4 volts for the loss in the bridge ..
Measuring DCC track voltage requires a meter designed for the purpose, or following a process to determine the voltage. The voltage on the track will be less than that supplied by the power supply.
It is possible that the power supply is defective, but ensure that you are using the right range/mode to measure its output, and if possible, have a load on its output when you measure it.
Measuring Track Voltage