I disagree with Mokemike also. They postwar ZW is great for running DCS, IF AND ONLY IF you have external fuses & breakers not exceeding 10 amps. Also, the breaker does not not activate unless the transformer overheats; it is thermal type and open the circuit when a heater wire in the breaker overheats. That said, the internal breaker isn't worth a hoot. I can't afford fuses, so I use breakers.