Bare minimum for AC power to track when NOT using legacy features?

The 685226 you're asking about (more commonly referred to as the Powerhouse 180 Watt brick) will only work with Locomotives and accessories requiring 18VAC fixed power (command control which includes LionChief, Legacy, Bluetooth, DCS and others).  The PH180 will not work by itself for conventional train operations.  Conventional requires a variable voltage to control train speed.  Most accessories also work better and last longer on a voltage lower than 18V.

The PH180 does have a very good circuit breaker that acts quickly to cut power in the event of an overload.  Distributed power connections to the track (feeders) may be through the 6-34120 TMCC Direct Lockon, but don't require it.  Feeders can branch directly from the PH180 to track connections around the layout.  There are many ways to accomplish this and would depend on the type of track you will be using.

It can be confusing - no doubt about it, but the Forum has a lot of information by using the Search function.

Conventional engines need a transformer with a mechanism (like a handle) to vary the power (voltage) to the track to be able to speed up and slow the train down. OTOH, command controlled engines like Legacy and TMCC require a constant 18 volts of power to the track if you want to run them under command control. So, generally speaking, you can't run both kinds of engines on the same track at the same time. Note that you can run a Legacy or TMCC engine conventionally, using a conventional transformer (see below) but you will not have access to all of the engines Legacy/TMCC features.

The 6-85226 Powerhouse supplies a constant 18 volts to the track - the voltage is not variable, so you cannot use it if you intend to run conventional engines - it is designed for running command controlled engines. In order to run conventionally, you would have to get a conventional transformer like an MTH Z-1000 or a Lionel CW-80. As above, you can run a Legacy/TMCC engine with a conventional transformer.

The 990 Legacy system is used to control Legacy/TMCC command controlled engines. The 990 base does not supply any power to the track - it only supplies a signal to control Legacy/TMCC engines. The power to the track is still supplied by a power supply like a transformer or Powerhouse.

It can be a hard concept to grasp at first, but think of it this way - command control engines require about 18 volts to run properly, whereas conventional engines run best at about 10-12 volts. Therefor (for all intents and purposes), you cannot run a command control engine and a conventional engine on the same track at the same time because if you set the transformer voltage at 10-12 volts for the conventional engine, the Legacy/TMCC engine will not operate correctly and if you set the transformer voltage to 18 volts, the conventional engine will fly off the track.

Even though hooked up to the layout, the 990 base signal does not interfere with the conventional operation. If you want the convenience of being able to run conventional engines using the 990 remote, then buy a Powermaster (not Powerhouse) and integrate it into the system using the 6-12893 cable. It allows you to vary the voltage to the track for running conventional engines using the 990 remote, much the same way as if using transformer handles.   

Hope this helps.

I should have explained.  I have no interest in running traditional.  I may have worded that wrong.  Everything will be some sort of a command controlled system.  Bluetooth or Modern Legacy. (maybe I'm using the wrong terminology.)

I'm planning on constant voltage.  I only asked if 612893 was all I'd need from powerhouse to track.  It looks like the powerhouse has a strange molex connector on it.

idaband,

It does but the 6-12893 cable is for a different use (from an old fashioned transformer to a PowerHouse).

Instead you need one piece within cable set number 6-14194, which has three, or four depending on how you count, adapter cables in it.  See the center assembly here, which has two independent adapters bound together.  You need 1/2 of it, and then perhaps a modification to the non-connector end so that you can attach it to your particular brand of track:

Mike

So what I circled in the Red.  is actually a pair of wires coming off.  Hard to see in that photo.  Neutral and hot? 

I'll just make a connector and solder direct to

Fastrack if need be.

That's it.  Presently they are U-shaped hook terminals, that you would insert under screw connections, say with a screw terminal block.

If they don't work with your track's power section then you could cut them off, and solder directly to your track, or remove them and replace them with the kind of (.110"?) Fast-On terminals that connect to the terminals found underneath FasTrack.

Mike