The PECO HO Code 100 switches come in two varieties, Insulfrog or Electrofrog.
Insulfrog are NOT power routing to the frog rails, this makes them DCC Friendly when installing them in a passing siding or when there is another switch at the opposite end of the siding. The advantage to Insulfrog is they are easy to install with minimum wiring, the disadvantage is small steam locomotives may sometime stall on the dead frog.
Electrofrog ARE power routing, this means the frog rails will be powered from the point rails (the rails that move). This will cause a short circuit on your layout when installed in a passing siding for both DC and DCC when the switch at the opposite end of the siding is set for the mainline and the opposite end of the siding is set for the diverging route. To eliminate this problem use insulated rail joiners on bothe of the frog rails. The advantage to Electrofrog is with small steam locomotive, because the frog is always powered the small loco’s do not have a tendency to stall on the frog.