DCC circuit breakers are a great tool is helping one manage the power problems associated with DCC's global layout power when running multiple trains with multiple operators. More specifically the problem of a short circuit shutting down the entire layout. Their biggest advantage is the fact they cost a lot less then buying multiple booster to solve the same problem. Below are some notes about known problems with DCC circuit breakers.
1) CIRCUIT BREAKER DOES NOT RECOVER AFTER SHORT
With the introduction of sound decoders to the mass market by locomotive manufactures such a BLI, Life-Like and Atlas, sound decoders have become common place on layouts. However electrically, sound decoders are a lot less tolerant of power interruptions for you instantly hear the results of loss of power....no sound. This become obvious on dirty track where the engine keeps moving physically but the sound does not. (The flywheels keeping the engine moving over the dead spots).
To partially remedy the most common levels of dirty track, sound decoder must store electrical power in the form a requiring a large capacitor. This capacitor electrically present a problem for DCC circuit breakers when they restore power. When the capacitor has run out of power, it needs to be recharged just like a battery. Recharge time only takes a moment to do and goes away when the capacitor become fully charged. Unfortunately capacitors looks like a "momentary" short circuit to a DCC circuit breaker creating a "false short circuit" due to the high amount of initial current needed to charge them. This capacitor problem is often covered by the terms such as "High Inrush Current" and "Sound Decoder Compatibility" when discussing DCC Circuit Breakers.
Existing DCC Circuit Breakers Solution: My friend and fellow DCC Guru Marcus Ammann has built up a excellent website page that talks about the problem and offers detailed information on how to solve it using common automotive light bulbs based on a suggestion I gave to him a long time ago. The bulb solution is valid solution to "OLD" problematic DCC circuit breakers that one has already purchased.
http://www.members.optusnet.com.au/nswmn/cb_sound_reset.htm
However in the long run, this a not a fix but a "Band Aid" to a problem can be also be address by using modern DCC circuit breakers.
Buy New Permanent solution: Many DCC Circuit Breakers have been redesigned to not cause this "false short circuit" recovery problem. In other words, they advertise themselves as being "Sound Decoder Compatible".
1) DCC Specialties: PSX series including the PSXAR which offers autoreverser function.
http://www.dccspecialties.com/products/powershield_x.htm
2) NCE's EB1. Replaces the discontinued EB3. For more information about the EB1 and how to use it, go here: NCE EB1