TVS Protection for ZW Transformer

A TVS is used to mitigate voltage spikes which occur when the loading on a transformer winding suddenly changes, as in the case of a short or other interruption.

These spikes can be in the order of 60 to 80 volts or more, which can serious damage modern solid state electronics. It was not an issue for postwar trains that had no electronics.

You can order inexpensive TVS's from mouser for less than 50 cents a piece in bulk.

They wire across the transformer hot to ground. Very simple and cheap insurance.

I will re-post with the commonly used part number shortly, unless someone else jumps in with it first.

Rod

There has been a lot of discussion about this topic. Investing in the Transient Voltage Supressors will pay off big time.

Check out the information at this web site

http://www.hirailers.org/

I tried to look that part up on Mouser but it did come up.

Thanks I got it should be
511-1.5KE36CA

Just wondering if this is really necessary if I am using the circuit breaker?  The TVS is fairly expensive maybe there is a cheaper way to go

No, it's not. TVS protection is built-into each channel of the DCS TIU.

In addition to using a TVS for reduction of voltage spikes at the TIU I have added separate 10 amp circuit breakers at the Output of all my KW transformers (I have 4).

I have added a TVS at each TIU input and TIU output.

Also I have added 5 amp circuit breakers at all the Outputs of my TIUs. (I have 2).

Also all my circuits which are controlled by my AIUs have both circuit breakers and fuses. Each of the AIU SW and ACC circuits are limited to no more than about 1 amp load for each relay circuit.

The Turnout (switch) solenoids are externally powered by a dedicated KW with an individual external 5 amp circuit breaker. The turnouts also have current limiting in the event of a switch solenoid failure (dead short) as well as fuses. On my layout I activate switches "in pairs" when controlling my crossover tracks.

I bought a bunch off Ebay. They are cheap. They are 1V5KE43CA. They breakdown at 38.6 volts in both directions. not sure how many you need but I have 30 or 40 left over. I am not really trying to sell them but if you need some PM me. Don

Not sure if this forum has PM so my email is : dontrinko@yahoo.com

Don, you can put your email in your profile so it's not posted in the clear for spammers to find it and bury you in email.