Bear in mind also that it's not just loco wheels that can cause this problem: any stock with metal wheels can cause shorts in this way if B2B gauge is too narrow. I have made the mistake of using a Peco code 75 Insulfrog long crossing and keep getting either shorts, or seeing sparks as the trains go over it. And my Maunsell coaches are just as bad as the locos. Not all shorts trip the booster, but slow moving trains do. I thought with no blades, and only straight roads, there would be no problem. Wrong! In my case it's wheels touching both rails at the frog, or bridging the outside rails where they join as the plastic insert is too small.
I'm having to install a DCC Concepts Masterswitch Plus to correct this, as it's too late to replace the crossing (all glued down and ballasted). The switch has 4 SPDT switches built in and is being used for the point that sets the road over the crossing (it's a double junction). Two of the SPDT switches provide power to the crossing rails according to how the points are set, and one will be used for the polarity of the frog on the point. All 8 rails on the crossing have been electrically isolated.
I'm having to install a DCC Concepts Masterswitch Plus to correct this, as it's too late to replace the crossing (all glued down and ballasted). The switch has 4 SPDT switches built in and is being used for the point that sets the road over the crossing (it's a double junction). Two of the SPDT switches provide power to the crossing rails according to how the points are set, and one will be used for the polarity of the frog on the point. All 8 rails on the crossing have been electrically isolated.
