Will sparking shorts damage TIU

Most certainly!  Any voltage transient that's causing sparking can very likely generate high voltage EMI, that's what kills the TIU drivers.

even a minor derailment can cause issues plus power interruptions from you electric suppler can damage tiu's and other boards!

Alan

@gunrunnerjohn posted:

Most certainly!  Any voltage transient that's causing sparking can very likely generate high voltage EMI, that's what kills the TIU drivers.

Does this fall within the scope of what can be protected against with a TVS?

One of the reasons I went BPRC!!!

@Oman posted:

Some wheels are shorting (sparking) on an Atlas 7.5 switch. I added a PSX-AC breaker. It doesn't trip. But, can the DCS signal drivers still be damaged? Should I correct this switch issue before damaging my TIU.

There are many scenarios where electrical mishaps can cause problems with the TIU DCS output drivers, and in extreme situations my hunch is sparking is one of them.  However, the sparking you see when crossing over switches is not necessarily shorting.  This could be typical electrical arcing that happens when loads disconnect and reconnect while energized.  

This isn’t to say that the behavior is 100% harmless, but it’s probably not the end of the world either.  I would recommend cleaning the track, rollers, and wheels with some DeoxIt D5 and see how that goes.

@Mallard4468 posted:

Does this fall within the scope of what can be protected against with a TVS?

To an extent, yes.  However as Adrian’s posts have shown us, the TVS devices need to be within an inch or less of what they are protecting to be effective in these situations.  This means inside the TIU and locomotives.  This is not to say that a TVS on the transformer output or connected to the track lock-ons is useless. They will offer some protection in certain cases.

Also, so as not to anger the train gods that lurk here, this isn’t to say that having TVS devices is 100% necessary, nor are they a total panacea to DCS signal degradation.  Quite the opposite in fact.  As GRJ has told us, a 0.22 mH choke is a good idea when you are using multiple TVS devices per circuit.

@Bob Delbridge posted:

One of the reasons I went BPRC!!!

Bob,

I hate to be a pain but I did a search for BPRC on Abbreviations.com and couldn't find anything that seemed to apply to trains:

Could you enlighten us?

Mike

BPRC = Battery-Power, Remote Control; the idealistic model railroad messiah that promises to eliminate all electrical gremlins *sigh*

@bmoran4 posted:

BPRC = Battery-Power, Remote Control; the idealistic model railroad messiah that promises to eliminate all electrical gremlins *sigh*

And doubtless introduce a whole new set of gremlins.

What was that about "The grass is always greener on the other side of the fence."?

Thanks to those that cautioned possible TIU DCS driver damage. I will apply the liquid electrical tape solution before I send the offending equipment through the switch again.

I've seen other comments on Atlas 7.5 turnouts, but an older generation than mine. It seems Atlas didn't address this problem. Look closely, you can see two bright spots on the second wheel set. Sparking on the diverging center rail. The locomotive was not on the diverging route. The wheels come in contact with the diverging center rail.

@gunrunnerjohn posted:

And doubtless introduce a whole new set of gremlins.

What was that about "The grass is always greener on the other side of the fence."?

Gremlins?!?!?!  John, I have had ZERO problems with BPRC in the 5+ years of operation that were caused by the electronics and not operator error.  Can you say that about DCS or TMCC?  You wouldn't be in the repair business if you could.

SMH (Shaking my head )

@Bob Delbridge posted:

Gremlins?!?!?!  John, I have had ZERO problems with BPRC in the 5+ years of operation that were caused by the electronics and not operator error.  Can you say that about DCS or TMCC?  You wouldn't be in the repair business if you could.

SMH (Shaking my head )

That's a rather qualified endorsement of battery power. I would imagine there are many folks who have been running AC powered for way longer than 5 years without electronics problems.

This issue is what power is applied. Your poke at DCS and TMCC is not relevant as they have nothing to do with what may cause EMI, they are victims.