AMPS--How Many?

TIU has internal 20 amp fuse on each channel to protect the traces of the TIU. 

Your power supply and your wiring will be your limit most likely.  Since your using 10amp fuses they will blow first.

Yes a diesel with 4 motors and 2 smoke unit should draw more than one steamer.

Normal PS-2 (3V) with smoke at idle 1.2Amps.  5V are higher sometimes by .5amps.  G

Thank you very much G. That's exactly what I was looking for. I don't run the smoke units when running all these engines and I do have some passenger cars running. I just got my 844 FEF at York this past fall and it works great. I'm not too happy with the thread here about boards failing in them though. Thanks again. George

TIU has internal 20 amp fuse on each channel to protect the traces of the TIU. 

Regardless, each TIU channel is rated for 10 amps maximum.

Keep a new battery in it, and we will keep our fingers crossed.  G

G Thanks for the tip. The battery in it when I got it was shot. Being anxious to get the beast fired up and running, I installed a battery I had available. If I had had  a BCR, I would have installed it. How do feel about putting a BCR in it? Why the comment about the battery anyway? I'm now thinking about taking some of my Diesels off the shelf and running them. I know what I'll be going through to get the batteries charged to get them back into the operating system. I may be in the market for a bunch more BCR's. George

George The board has to charge a battery or a BCR.  The exact mechanism of the failure is not known, but some have the diodes that rectify AC for powering the circuit board short.  There also is a Power FET I have found that shorts.  A battery that is fully discharged or worst shorted/dead could potentially cause a failure.

Some suspect bad batteries as one of the failure modes (I agree).  I can't prove or disprove, but I think it makes sense that the circuit only be asked to trickle charge vice maximize a charge.  Plus it prevents a dead battery that becomes a short.  G