sparks as train runs across switches

Are your transformers in phase?  John in Lansing, ILL

good question - how would I know 

I have a Type Z 250 powering the track and a Lionel Transformer Model 6-03-2934-000 with 18 vac output for the switches set at 14 vac

Do the transformer plugs have two prongs or two prongs and a ground?  Are they plugged into the same outlet?  If they have two prongs, turn one of the plugs around and see if the trains spark.  

Your third sentence - Both were modified...          How did you modify them?  Have you switched transformers to do the other's current(pun intended)  function?  John in Lansing, ILL

they are both 2 plug transformers - I will try that tonight.

Lionel had a you-tube video for the 0-27 switches, that you cut the wires going to the coils and connect them together to a set power source - other than track power, so if the train is running slower the switches will completely transfer

What style of O27 switches are they, 1121 or 1122?

Dirty track maybe or if it's a Williams loco, the because the center pickup is wider than others may also cause this.

Too high of fixed voltage applied will cause excessive sparking.

Switches are 5121 & 5122 remotes

I do not see it as much on the engine as I do with the cars as they run across

badrepp posted:

they are both 2 plug transformers - I will try that tonight.

Lionel had a you-tube video for the 0-27 switches, that you cut the wires going to the coils and connect them together to a set power source - other than track power, so if the train is running slower the switches will completely transfer

Search Youtube for Lionel- phasing two or.more transformers to be used together and why.(or sumpin just like dat).   If you aren't careful you might learn something; I highly suggest it.  (Mike is pretty entertaining, good watch)

Two transformers wired together out of phase can create over voltage output (30-40v+)

Train Nut posted:

Too high of fixed voltage applied will cause excessive sparking.

yep. if they only need 12v to trip, use that. (and mind the heat build up when looping long trains will be higher temp at higher volts).  These coils need rest time during running too.

Dirty wheels, and dirty track make for sparks. The railhead and inside railhead edge (or aboit 50° or tubular railhead) should shine some. Over polish and you'll need to scuff it some for traction.

Some spark is almost guaranteed though as there is a fresh, kinda strong pulling electrical connection being made by the wheels.  

A very light loco might spark less with weight added: pressure has a huge impact on lowering resistance at a contact point.(HUGE)

You might try some crc electrical cleaner on a rag for cleaning wheels/rails. It leaves behind a alight electronic and metal friendly coating, not noticably a traction issue.

To best eliminate sparks, use a low power relay on the trigger rails and the relay's point's side can pass the high power feed to the sw.coil.

Or use a modern light based proximity sensor (looks like a trackside electrical box) 

I watched the phrasing video. Houston we have a proble .  I checked the voltage on me switch. With the switch in the straight thru setting with the track transformer set to 15vac. I have 15vac on the straight and 29vac on the siding . I need to fix that.