DCC POINT MOTOR WIRING

[robertwm3110]

I recently had to replace my NCE command unit, possibly a short somewhere seemed to do for it. It has been replaced but now most of my point motors dont pass current to the frog. I use the cobalt IP digital and they are connected to the power bus with a wire from the third terminal marked “frog” running to the frog. Now some points have a dead frog, some will provide current when just running one way through the point, although one works fine. The NCE cab seems to find them all under their previous accessory number. Any ideas anybody. Do i need to reprogramme the point motors now that I have a new command unit. But why does one point work ok. Could the motors be damaged from the previous issue I had - but as I say they work in terms of moving the point.

[newbryford]

I recently had to replace my NCE command unit, possibly a short somewhere seemed to do for it. It has been replaced but now most of my point motors dont pass current to the frog. I use the cobalt IP digital and they are connected to the power bus with a wire from the third terminal marked “frog” running to the frog. Now some points have a dead frog, some will provide current when just running one way through the point, although one works fine. The NCE cab seems to find them all under their previous accessory number. Any ideas anybody. Do i need to reprogramme the point motors now that I have a new command unit. But why does one point work ok. Could the motors be damaged from the previous issue I had - but as I say they work in terms of moving the point.

 

The frog switch(and the S2 switch) on a Digital IP are just sliding contacts within the motor housing. They have nothing to do with the address.

The S1/frog terminal simply switches the "DCC in" connections to the motor - very useful if you have the accessories powered from the track bus.

 

The S2 L/C/R terminals are completely independent and switch from L to C or L to R depending which way the point is set. Useful if you have separate power for the track and accessory bus wires.

 

There is a possibility that a high current short may have caused the tracks on the pcb to fail. I've seen them burn out when they were switching a booster rated at 8amps...... (it wasn't me BTW!)

 

Disconnect the wire from the frog and then check the continuity from each side of the "DCC in" to the S1 terminal in both positions - make sure the DCC is off whilst you do this to prevent any false readings.

(Obviously turning the DCC on to switch the motor from one side to the other.)

 

Cheers,

Mick