Reverse Loop ????????
- Thread starter Sharecropper
- Start date
cv_acr
Well-Known Member
Simple answer:
DC or DCC you have the exact same issue. The polarity must be reversed when you go around a reverse loop or a short will happen.
The advantage of DCC is you can get an electronic auto-reverser that automatically detects this and reverses the current for you, so you don't even have to think about it when operating.
With an engine going around a loop and back into the track you came from, the polarity for DCC (or DC) must be matched for direction.
Although the main track polarity never changes, the loop back causes the outside rail to become the inside rail going in the opposite direction. This would cause a short if connected. The only way to correct this is to isolate part of the track in the loop. This length needs to be engine (+tender) long or as long as a lighted passenger train.
Both rails of this section needs to be isolated and at both ends.
A double pole switch supplies the isolated track with one pair of polarities on the up switch and the opposite track polarities on the down switch.
Just before entering isolated track, the switch is moved to the position to match that track.
Before leaving the isolated track, the switch is moved to the position of the return track.
The switch can be replaced (recommended) with an automatic electronic reverser. Then you don't have to do anything before running your engine around.
Although the main track polarity never changes, the loop back causes the outside rail to become the inside rail going in the opposite direction. This would cause a short if connected. The only way to correct this is to isolate part of the track in the loop. This length needs to be engine (+tender) long or as long as a lighted passenger train.
Both rails of this section needs to be isolated and at both ends.
A double pole switch supplies the isolated track with one pair of polarities on the up switch and the opposite track polarities on the down switch.
Just before entering isolated track, the switch is moved to the position to match that track.
Before leaving the isolated track, the switch is moved to the position of the return track.
The switch can be replaced (recommended) with an automatic electronic reverser. Then you don't have to do anything before running your engine around.
