Here is how I would set up your power for command only.
The Transient Voltage Suppressor (TVS) is highly recommended by many on this forum to protect the more delicate electronics in new command engines. They are cheap.
The fuse (or CB, but those are not as fast) is not really needed with the PH180; its internal CB is about the fastest you can find. Some folks feel better using a fuse/CB of lower value (5 or 7 amps) if they don't need much power to run a smaller layout, or only run one engine and a few lighted cars. Anyway, I think the PH180's CB is good enough by itself.