Will the use of a TVS across the output of a TIU cause any degradation of the DCS Signal?
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No it should not. The TIU has an internal TVS. G
Don,
I am not a certified Tech like GGG, I did own an original 1st generation TIU long ago, it was the bare bones inital TIU, I put Scott 10 Amp breakers between it and my ZW transformers and never had a problem, the newer TIU's have both 20 Amp fuses and TVS pertection built in, and I still use the Scott 10 Amp breakers. I really do not think you need additional TVS protection, but hay it could not hurt!
PCRR/Dave
If you're concerned about spikes, you could put the TVS across the input to the TIU. Blocking the spike at the source will keep it out of the TIU and subsequently out of your track without inhibiting the signal. As for a circuit breaker, you want a fast trip breaker between your TIU and the track if using an older transformer. If you're using a Z4000 the extra breaker isn't necessary.
Matt,
you want a fast trip breaker between your TIU and the track
No, you want it between the transformer and each TIU channel input.
Gentlemen,
Place the Breaker on every Red terminal between your transformers and the TIU Channel input, Barry is correct as usual. TVS is internal to the TIU, and I still recommend Scott type 10 Amp Breakers in front of every transformer/brick no matter how good the brick or transformer happens to be, even the LH 180 which has an incredible electronic breaker of it's own. IMO it should have a 10 Amp breaker in front of it and the TIU also, if you want absolutely no problems, and easy reset.
PCRR/Dave
Originally Posted by Barry Broskowitz:
Matt,
you want a fast trip breaker between your TIU and the track
No, you want it between the transformer and each TIU channel input.
Matt,
I guess you missed the following thread on the installation of placing a 10 amp fuse between the TIU and track resulting in blowing the 20 amp fuse inside the TIU.
Originally Posted by AGHRMatt:
If you're concerned about spikes, you could put the TVS across the input to the TIU. Blocking the spike at the source will keep it out of the TIU and subsequently out of your track without inhibiting the signal. As for a circuit breaker, you want a fast trip breaker between your TIU and the track if using an older transformer. If you're using a Z4000 the extra breaker isn't necessary.
Some would say those spikes can also be generate on the track, via accessories, train derailments etc... So one line of thinking is putting them at various points around the track. G
Of course, since the TIU has TVS diodes on each output, you don't really need them there, but I agree with GGG, sprinkling a few around the layout can't hurt. Any inductor that suddenly loses power can generate a spike, and some of those spikes can be hundreds of volts in amplitude.
Todd,
If you already have the 10 Amp quick blowing fuses you are set, however I like the breakers because they are easy to reset, Scotts has been bought out by Train Electrics LLC, you can find them on the Web, or call them at 231-631-0447. They still stock the original Scott type 10 Amp Breaker banks. As far as the TVS I relied on the built in TIU TVS and have never had a single problem on any of my layouts.
PCRR/Dave
Todd you can see a couple sets of the 10 Amp breaker banks in front of my Transformers in the picture below, look for the white strip 3" long, the breaker buttons are just above the strip,
real easy to work, they pop up when there is an over load, simply cut the power and push back down to reset, with no cost to replaces fuses, I use the Breakers.
If you already have the 10 Amp quick blowing fuses you are set, however I like the breakers because they are easy to reset, Scotts has been bought out by Train Electrics LLC, you can find them on the Web, or call them at 231-631-0447. They still stock the original Scott type 10 Amp Breaker banks. As far as the TVS I relied on the built in TIU TVS and have never had a single problem on any of my layouts.
PCRR/Dave
Todd you can see a couple sets of the 10 Amp breaker banks in front of my Transformers in the picture below, look for the white strip 3" long, the breaker buttons are just above the strip,
real easy to work, they pop up when there is an over load, simply cut the power and push back down to reset, with no cost to replaces fuses, I use the Breakers.
Originally Posted by Joe Allen:
Originally Posted by Barry Broskowitz:
Matt,
you want a fast trip breaker between your TIU and the track
No, you want it between the transformer and each TIU channel input.
Matt,
I guess you missed the following thread on the installation of placing a 10 amp fuse between the TIU and track resulting in blowing the 20 amp fuse inside the TIU.
You're right. I missed this thread. My recommendation is based on what happens to older TIU's used with some transformers -- the TIU fries before the thermal breaker trips. The 10-Amp fast-blow goes when the train derails.
