Engineer-Joe posted:Ryaninspiron posted:In general is it a sign of bad TVS diodes if each TIU (PASSIVE MODE) output channel is drawing 0.2Amps? One of main rail lines(several hundred feet long) has a 2 Amp draw with an empty track as soon as the TIUs are connected.
I believe you are actually answering (can answer) your own question. If the draw goes away with the track dis-connected, it has nothing to do with the TVS.
I believe TVS pieces fail either open or a dead short.
Stay posted. Someone will tell me I'm wrong again.
A .2 amp draw could be some shorting at switches or similar. A 2 amp draw seems more severe.
Does this draw go to different TIU channels if you move it?
If you haven't tried just the TIU to the power source, try it. Of course, if you have ignore this. It's always hard to tell at a glance who has done what.
At the TMB club layout the transformer is almost always connected to the track. There are relays that connect the several TIU output channels to different points on the track when a central "DCS Power" switch is turned on. This keeps the TIUs isolated when they aren't being used. What I was trying to convey is that the empty track with no TIU draws no current. When the DCS relays connect the TIUs into the track we suddenly draw about 2 amps according to the z4000. If i start unplugging TIUs the current drops by .2 amps per channel. The TIUs are all run in passive mode.
Should a totally passive mode TIU draw any current through just the output jacks on its own?
