I have an MRC Tech 6 “hybrid” DCC/DC controller. Thought I would connect an EB1 circuit breaker to prevent short circuit damage to a locomotive when using DCC mode. The directions say that the circuit breaker is not to be used for DC. If the controller were to be operated in DC with the attached circuit breaker, is this risky? What would happen?
Realizing that in DCC mode (N Scale) the system is operating with a maximum of two (2) amps; what is the amperage while in DC mode?
Everything that I read about the EB1 simply says that it will not work in DC mode. It doesn’t caution about any damage if you do connect it to a DC power source.
Rich
Thanks. I tried poking around the web for info and couldn’t find anything. My guess was that the DCC features wouldn’t work on DC and that makes sense. I assumed it would simply be a dumb circuit while on DC mode.
The designer of the MRC Tech 6 and their other products is currently doing some DCC sound decoder installations for me. His English is very limited and I didn’t want to bother him. Thanks so much for your response.
xyz
Yep, that’s the way I interpret it. Just informational, but not a warning.
Rich
I did a little searching of the web but didn’t get a definitive answer. I suspect the problem is the reversing polarity of DC systems.
a common way to measure power is thru a high power shunt resistor. I see what i believe is a 0.05 Ohm resistor on the EB1. Using this approach, the processor needed to measure the the voltage when the DCC polarity makes one end of the resistor Gnd. Because of this,it won’t work with DC because it would only work in one loco direction/polarity and not in the other
in DC, the max amperage depends on the throttle setting
Hello All,
My suggestion is to contact NCE directly and ask them.
All the tech questions I have posed to NCE have been answered quickly and concisely.
If the NCE tech support teams have further questions about your inquiry they will begin a dialogue to answer your query.
Hope this helps.
I would be surprised if any brand of DCC breaker worked with DC. The logic is based on the AC waveform of DCC. No idea if they would be hurt, but will likely not pass the DC through. And I agree with @jjdamnit . Just contact the vendor.
You could always wire a bypass around the breaker that you would flip a switch to engage when in DC mode.
Why bother?
NCE says it won’t work with DC.
Rich
“. . . but will likely not pass the DC through.” Do you mean that it could block DC power from reaching my layout?
Yes, that is what I would expect. I could be wrong.
It would be unlikely that it would block DC. It could look for a valid DCC waveform and block it if there isn’t one, but I doubt it. As Greg mentioned, it is possible that it only checks for over current during one phase of the DCC signal. If that is the case, then it would only shutdown on one DC polarity and not give any protection on the other. The Tech 6 uses the same H-bridge for DC as it does for DCC, so the maximum current would be the same.
So what is the conclusion relative to the question of damage. Would the EB1 itself be damaged? The transformer? Anything? Nothing?
Rich
Rich, I think we all agree it won’t work in DC. I think the question now is would it harm anything if used in a DC system, hence ask NCE.
Regards, Chris
Well, yes, that is the question, and it is the question that I asked in the prior post. I was asking it here because there have been some knowledgeable replies. So, I am asking for those who have replied to this thread to draw their own conclusions and state them here. I have no interest in contacting NCE.
Rich
doubt the circuit breaker would cause any harm that wouldn’t otherwise occur due to a short. The EB-1 can work with currents up to 8A
Asked and answered. Thanks Greg.
Regards, Chris