Blog Entry from NCE Website:

The Power Cab Introduction
The PowerCab is the best solution for a small layout or anyone starting out with DCC. Extremely easy to setup. Most people can run trains in 10 minutes. Usually 1 or 2 operators. Maximum of 4 cabs / operators on a single layout. The Power Cab must be plugged in on the left side with the flat cable to run the layout. Use an Eb1 (v1.1) to protect the Power Cab against short circuits. The Power Cab has 2 amps of current output capacity @ 13.8V track voltage. (Note:: DCC is measured as AC; z.scale.hobo NOTE: AZL locomotives work fine with this voltage/current setup, but you must have installed short-circuit protection!) The Power Cab is good for about 4 HO scale locos or 8 N scale locos running at the same time. Locomotives that are parked not in use can remain on the layout because they draw VERY little power. We do not include them in our calculations.

The seven foot long, 6 wire FLAT cable for the Power Cab contains full track power and the wall power from the included 2 amp power supply. The cable used for the Power Cab is thicker and heavier for this purpose. You cannot substitute ANY other type of cable. Using NON NCE CABLES WILL VOID YOUR WARRANTY. Longer cables or coiled cables are not available or recommended.

A second cab like a Cab06 (5240039) or a Pro Cab (5240010) can be added with a longer cable. You can also add a second panel, a UTP (5240207), for the second cab to be used in a second location. The Power Cab will still need to stay in the original Power Cab Panel using the original 7ft. flat cable.

The replacement power supply for the Power Cab kit is a P114 (5240221). Using ANY other Power Supply is not recommended and will void the factory warranty.

The Power Cab has built in overload for basic self-protection that will continuously try to reset the Power Cab ever 1/2 second (500ms) until damaged if it is left uncorrected. The Power Cab does not have circuit breakers that will trip or fuses that will blow. Use the new EB1 v1.1 electronic circuit breaker to protect the Power Cab against short circuits.

Make sure you add a DCC track power circuit breaker like the NCE EB1

Why Do I Need A DCC Circuit Breaker? Myth Vs. Fact

All NCE systems and boosters have built in over current sensing for basic self-protection that will continuously / automatically try to reset every half second (500ms) until the unit is damaged. They do not have manual breakers that will trip or fuses that will blow. The default trip rating of an EB1 circuit breaker is 16ms. That is roughly 30 times faster than the standard booster overload trip time!

The reason you would add protection of some sort is that you do not want the entire railroad to shut down if you have a short. You break it up into smaller pieces. All of our systems will only try to protect themselves and not your locos. Use the EB1 to divide up your layout and protect your trains! Think of this like the breaker panel in your house.

You can have a short circuit in a decoder but there is no guarantee it will trip a DCC circuit breaker or shutdown a booster. Myth: DCC circuit breakers protect decoders. Fact: DCC circuit breaker protect boosters.

The goal of the DCC circuit breaker is to protect THE BOOSTER by isolating the short locally within the breakers power district so the booster can remain powering the OTHER power districts to keep the other parts of the layout running.

For the DCC circuit breaker to act, a short circuit has to meet specific criteria.
a) The short circuit current must be above the trip point of the DCC circuit breaker.
b) The short circuit current must last for a period of time.

NCE's EB1