NCE EB1 breakers

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079720
Posts: 8
Joined: Fri Jul 03, 2009 7:05 pm

NCE EB1 breakers

Post by 079720 » Wed Jun 05, 2019 6:05 pm

Calder Northern are having an issue with our EB1 circuit breakers and are looking for a solution or something better. If there is a short close to the command station, i.e. close to where the power is fed into the track bus for the power district, then all of the breakers trip. If the short is at the far end of the power district, in our case this can be up to 50' from the power feed, then only the shorted power district is tripped. We are not alone with this issue, I have found it reported by others on an internet DCC group but no one seems to know why it happens or how to solve it.

Any of you DCC experts out there got any ideas or suggestions? The breakers are set to 2.5 amps, three breakers to the command station and three to the booster with 5 amps available from both the command station and booster.

Mike_R
Posts: 398
Joined: Fri Jul 03, 2009 7:05 pm

Re: NCE EB1 breakers

Post by Mike_R » Wed Jun 05, 2019 6:50 pm

The only thing I can think is that further away the cable / track resistance will lower the fault current, does the closer higher fault current drop the booster voltage. The breakers would trip when the voltage goes below some value.
Do all breakers trip or just the three on the booster feeding the short? If just three is it the booster tripping or as above?
Do the boosters feed back trip information to the command station and other boosters such as Lenz can? If set up on Lenz, one booster tripping can turn all off.
How much load is on the boosters? i.e. can a higher fault current go over the booster limit.

I use PSX circuit breakers, one of my setups has two boosters feeding two breakers off each. I only loose two outputs if the booster is pushed too far and turns off. Our group has about 10 PSX's in use. The only problem I've come across is newer PSX breakers with default settings are faster than Frog Juicers.
Mike Ruby

079720
Posts: 8
Joined: Fri Jul 03, 2009 7:05 pm

Re: NCE EB1 breakers

Post by 079720 » Wed Jun 05, 2019 7:40 pm

Mike, thank you fo ryour reply. We have Digitrax DCS210 command station and a DB210 booster. Each of these have three EB1's attached to them, which are set to a trip current of 2.5 amps. The command station and booster are both set for 5 amps. When we tested this there were no locos on the layout and we were using a larger washer to short the tracks. When a short occurs close to the DCS210 or DB210 the three EB1's will kick out but it doesn't look as though either the DB210 or the DCS210 does as the track power lights stay on. a short at distance just drops the one power district.
The breakers on the other box are not affected so only half the layout shuts down. You might be right about the voltage dropping when a short occurs I would need to read the EB1 manual to see if they are voltage sensitive.

As to information from the DCS210 I'm not sure, we've only had the system in place since March and it showed up so many wiring faults on the layout it has been a mamoth task to clear the crossed feeds, juicers drawing power from one district and feeding frogs in another, 12 years of uncontrolled modifications actually, so we're still getting to grips with what the Digitrax can do.

Thanks fo rthe pointers and I'll keep you updated with progress, or lack of it.

Mike_R
Posts: 398
Joined: Fri Jul 03, 2009 7:05 pm

Re: NCE EB1 breakers

Post by Mike_R » Wed Jun 05, 2019 8:58 pm

With three going at a time definitely sounds like the voltage dropping. The circuit breakers will drop out at some voltage as they need power to stay switched on and like PSX they must be taking it from the DCC power in.
Have you got large enough wires from the booster to the breakers, and bad contact would cause the voltage to drop.

If you can measure the voltage at the booster output and then at the breaker input during a short, that will tell if it is the booster or the wiring. If it drops more at the breaker that extra drop is the wiring.

One other thing are you supplying the boosters with power supplies rated at least 5 amps and a couple of volts more than the track voltage. If the supply isn't good enough the booster will drop voltage as it loads up. I've known a Digitrax booster not trip, but the voltage just dropped off because it was under powered.
Mike Ruby

signalist
Posts: 6
Joined: Tue Jun 24, 2014 10:54 am

Re: NCE EB1 breakers

Post by signalist » Sat Jun 08, 2019 11:48 am

The breakers will need to be near the booster. As stated above the problem is most likely due to a drop in track voltage at the input to the breakers. If the breaker is half way between the booster and the fault you will be seeing half track voltage at the input to the EB1(s) during a short which they will not like.

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