Solenoid Power Supply : plaited 3 wire

[RogerB]

Just reading an article on the DCC Concepts site about this product of theirs and wondered if the usual 3 core wire in a sheath would similarly overcome any interference? This is on a points crossover.

At what sort of distance from the CDU would you need to worry about the interference having an effect on the solenoids?

R-

[Brian]

Hi
I have never heard of 'interference' effecting any Solenoid point motor? I can see no reason why 'Interference ' would cause any issues.
A pulse of power is needed from the operation device (CDU or Accessory decoder) to the solenoid which lasts around 0.2 to 0.3 of a second.

Can you be more specific as to where this cable or wire / interference is mentioned?

Where a solenoid is operated from an Accessory decoder I would try and keep that decoder as close to the point motors as practicable purely to try and avoid any volt drop in the operation wires. But using 16/0.2mm wire should allow at least 4 mtrs from a decoder to the solenoid motor before issues arise.

[RogerB]

I was looking on the DCC Concepts website at the ADS-8SX to control some new Hatton's Solenoids and saw a reference to the plaited cable in question here. I have a very small layout now and cable runs will be well within the 4 mtrs you mention. I had only come across plaited wire in terms of the main control bus. This I suspect is pure marketing effort. R-

[RFS]

At over £1 per metre it does not come cheap. Solenoid motors have been around for decades so why has this need not been realized before? As you say, I suspect it's purely marketing... Even with just 4m length, factor in the motor cost, accessory switch if using live frogs, CDU etc. then a much better solution would be to use slow-motion point motors such as Tortoise or Cobalt.

[Brian]

Ah, I understand now! Its plaited or twisted into a group of three. Its induction not interference they are talking about.. Induction can occur in longer wire runs, but its not that much to worry about, if at all.
Three drums of 100 Mtr per drum (300 mtrs) of 16/0.2 from CPC Farnell will set you back £30.00 ish post free https://cpc.farnell.com/w/search?st=equ ... csa=0.5mm- If you want to then plait or twist them together yourself and save £s

If a CDU is used where manual switching is also used the CDU has discharged before the switches contacts open which is where without a CDU arcing occurs and contacts burn out.

[RogerB]

Its induction not interference they are talking about.

Ah, I really must find my glasses. R-

[Tricky Dicky]

I cannot see induction being an issue with solenoid motors and I am a little unclear how the plaiting will save switch contacts, I presume they are talking about the BEMF spike you will get as the magnetic field in the solenoid coils collapses.

Anyway, a quick method of plaiting individual wires is to use a hand drill (the type you turn a handle by hand to rotate the chuck). Insert a hook into the chuck, twist your wires onto the hook, tape to ensure they do not slip off, hold the other end of the wires in a vice or other fixed holding device and keeping the wire taut turn the handle until your length of wire is plaited to your satisfaction. Couple of points, do not use an electric drill you could find yourself in a tangle and even risk injury also cut your individual wires oversize as the plaiting will have a shortening effect on the overall plaited wires.

Richard

[Ron S]

the induction may not affect solenoids but may create problems in any other DCC circuitry whose wiring is close to the solenoid wires - all depends on how the wires are run under the baseboard.