This is the DCC Concepts Intelligent DCC Circuit Breaker [DCD-iPCB.1]

WILL NOT WORK WITH THE Digitrax DCS52 Zephyr Express 3amp DCC Starter Set

Perfect for all brands of DCC systems, including low-powered starter systems such as Hornby, NCE and Prodigy systems. The DCCconcepts Intelligent DCC Circuit Breaker (iP-CB) works “out of the box” to protect your layout and DCC system against damage caused by overloads and short circuits.

Simple-set jumpers for current limit selection between 1.25A and 5A.
Easy screw terminal connections for track power input and output, trip warning LED, manual reset switch and ESP connections – no solder pads!
ESP connection allows for installation of wireless remote panel indicator
Simple-Set screw adjuster for trip sensitivity so that you can allow for stay-alive charging on your locos
Protective aluminium casing above and insulating pad below for safety

In most cases, simply take the Intelligent DCC Circuit Breaker out of the packaging, connect to your DCC bus wires and you’re done!

Dimensions
150mm wide
62mm high
25mm deep