Wiring Hornby points

[deltanw12]

I have wired a number of Hornby points and point motors (R8014) in sets of two to be operated from one switch without any problems. But I have one pair that although the point motors work fine individually they refuse to push and pull when wired together. I have ruled out a problem switch, have wired them exactly the same as other pairs and have a CDU fitted. Layout size 8x6.

Can anyone suggest what may be the problem?

Thanks

[HLT 0109]

My Hornby points are DCC operated and I use the surface mounted motors but I have recently had a similar problem so my experience may be helpful. I discovered that one of the motors in the pair was weaker than the other and the problem was solved by replacing that motor. As soon as I wired two good motors together they operated perfectly. I concluded that the weak motor was drawing too much current. If you have a spare motor it might be worth substituting each of the pair in turn. I am not familiar with the use of CDUs but others may be able to advise on that.

[Brian]

Hi

Two motors from one switch and CDU fed should work ok.

 

You need to ensure the wires to each motor are taken from the point switches terminals and the wiring is not just one pair of feed wires then linked across from one motor to the other.

The wires to all motors need to be at the very minimum 16/0.2mm equipment wire and better still is to use a larger wire size.  The return wire, especially if one is shared for both motors, needs to be at least 24/0.2mm and again better still if its even a larger wire size.

[RAF96]

Due to awkward track geometry and lack of available space I'm lumbered with a paired set of Hornby points, one with a surface mount motor and the other the usual Mk2 solenoid and thankfully a G'Master CDU whacks them both over together no problem.

Rob

[macgeordie]

We recently had a similar problem on one of the club layouts and the simple solution was to feed the CDU with 24 volts a.c instead of the usual 16 volts from an auxiliary output on a controller. I strongly recommend the use of a CDU as it protects your point motors, particularly if you get a switch problem whereby the motor is energised for more than a few hundred milliseconds. Most CDU's will accept 24 volts as a maximum input voltage. This gives you about 35 volts dc accross the CDU capacitor, the pulse from which will fire virtually any point motor unless the motor is mounted out of line with the tie bar or, you have an auxliliary switch mounted on the motor which is a bit sticky.

[Donw]

You seem to suggest that neither work when wired together. If they will each work singly this implies either the wiring is insufficient or there is a bad contact. Are any other pairs working ok if they are it implies the CDU is ok. If could be that these two require more effort than others (poor alignment?) and the power from the CDU through the wiring is not quite enough for two but ok for one. I have fired up to six Peco point motors together using a gaugemaster cdu. If any didn't fire first time a second go worked becaause those that have fired then have a higher impendance ( once the iron core has moved into the coil) and leave more power for any that haven't.

Don