I recently added an NCE EB1 Circuit Breaker to my HO scale layout between the track bus and the MRC Prodigy Advance (not squared) DCC system. As planned, the EB1 trips faster than the built in MRC breaker so the command system stays powered up when the EB1 trips.
The problem I'm experiencing is that the EB1 does not seem to be able to automatically reset after the short is cleared. The breaker tries to reset but usually cannot restore power (although it did manage to reset twice). If I turn the whole system off and back on, the EB1 comes right back up. However, the idea is to keep the MRC system powered up while the EB1 takes over the short protection chores. The EB1 directions that NCE supplied with the unit are a bit vague and following their programming directions has not corrected the problem. An internet discussion I found says that the automatic function is turned off using the default NCE settings and that you have to reprogram CV 135 to a value of "4" to get the auto reset to function. I tried this but the unit still won't reset on its own.
I do have several sound equipped locos on the layout as well as several non-sound locos equipped with keep-alive circuits. The built-in MRC breaker has never had a problem powering back up after a short is cleared and the EB1 comes right back up if power to the system is turned off and back on. This would indicate that the current inrush is not the problem. The EB1 can be configured fo manual reset but I don't have a momentary push button switch on hand to try it.
Any suggestions on how to program the EB1 breaker for automatic reset?
Hornblower
Did you put the setup jumper on before using Ops Mode on address 9999?
CV135 is part of a table to build a custom startup profile in case there is problem with inrush - you do not need to set this unles it trips out the command station. CV131 controls automatic reset. The default is 0, which is auto reset, a value of 1 means it waits for the pushbutton.
CV130 controls how long it waits until it tries to reset. Defualt is 2 seconds. WHat happens if yopu put a quarter ont he rails, and then take it off within 2 seconds of the breaker tripping, does the power come back on? You may have to change the CV to increase the time to allow you to clear th short.
You can do a manual reset with the cab as well, by setting an accessory address and then Selecting that address and using on/off (close/open, or whatever terminology MRC uses). You have to set CV131 to 1 to enable manual reset. You can also use a piece of wire to touch to the two terminals where the pushbitton would go - this isn;t a solenoid switch machine where more than a fraction of a second of contact will fry something. You can't just screw in a jumper wire, but a quick touch to emulate a pushbotton is fine for a test.
This is the difference between the built in protection, which protects the booster and doesn;t care about your locos or decoders, and an actual circuit breaker that turns the power off and doesn't endlessly keep turning the power back on to see if the short is actually gone (which is what causes the problems with the built in protection on the system). I plan on mounting an LED and pushbutton on the fascia for mine and setting them all to manual mode.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy
Thanks for the response. Essentially, I installed the EB1 breaker between the command unit and track, turned on the power, and conducted numerous "quarter" tests. The EB1 would definitely trip before the command unit breaker which is exactly what I wanted. However, the EB1 struggled to automatically reset. The status LED would blink and you could hear a soft clicking noise as the EB1 tried to reset but only managed to do so twice in dozens of tests. I would wait as long as 20 seconds watching the EB1 struggle to reset. Eventually, it would simply stop trying. As I previously stated, turning the entire system off and back on would bring everything, including the EB1, right back up so I don't think its an inrush problem. I picked up a momentary push button switch yesterday so I'll test whether I can reset the unit manually.
Either the EB-1 is bad, or there's something wired to the tracks causing a load - if I understand it that you tested things with the quarter and NO locos on the rails. The EB-1 shouldn;t have any problem turning back on if there is nothing on the track.
Randy, exactly how does the EB-1 reset itself? What he's describing sounds like a mechanical relay; what would make it improperly pull in and reset, but come up perfectly after a hard power-off?
It's electronic, so it appears to be still seeing a short when it tries to turn the power back on. Or somethjing is sagging the supply from the DCC system - the EB1 is self powered so if the DCC voltage is dropping too far, it could cause it to not be able to run properly.
rrinkerIt's electronic, so it appears to be still seeing a short when it tries to turn the power back on.
After further experimentation, the problem is indeed an inrush current problem. With no or few locos on the tracks, the EB1 powers right back up after the short is cleared. The soft clicking noise turned out to be one of my sound equipped locos almost starting up its sound when the EB1 would try to reset with all my locos on the tracks. I was able to set up the manual reset function so I can always use that if I can't solve the inrush current problem. It just seems odd that the EB1 can handle the inrush current when the system is first powered up but not following a short.
Is the MRC system droppign out? Maybe that's what's clicking? There's nothing mechanical on the EB1 that can click.
Is this behavior with CV135 set to 0, or set to some other value? If thsi happend with CV135 set to 0, this might be a place to use the table and set CV135, I'd say try 2 or 4. And set CV144 to 4, CV145 to 130, and CV145 to 4.
Did you adjust the trip current on the EB1? By default it's set to 1.5 amps. THe dip switches set the current, try 2.2, or even 3.3 amps. Try this first, with CV135=0
Sorry I couldn't get back to this thread for a few days. However, I think I've got my problem solved. As suggested by another user, I reprogrammed CV 135 to a value of 4. I did not reprogram any other CV's in the default table, just CV 135. Bingo! The EB1 now resets automatically with ALL of my locos on the layout. Go figure.
Just in case I run into future problems, I picked up a couple of push button switches and tried changing CV 131 to 1. Manual reset works fine as well. I reset CV 131 to 0 and changed CV 135 to 4 and everything works exactly as desired. The EB1 trips faster than the built in breaker which keeps the MRC Command Unit (and the WiFi Module) powered up so my smart throttle users shouldn't have any more problems.