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Old 06-04-2016, 11:11 AM   #21
Cilfan
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Time to risk being given a pointy hat and told to stand in the corner methinks.

Can someone please explain the difference between say 12/02mm and 7/02mm other than the blindingly obvious fact that ones bigger than the other? It's the common denominator second figure (irrespective of size) that's confusing me. Also is there such a thing as "one (or two) size(s) suits all? Thereby limiting the number of different sizes needing to be purchased and allowing for economy of scale (larger reels) to come into play.
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Old 06-04-2016, 11:24 AM   #22
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As I understand it the first number (the one you know) is the strand count and the second one is the diameter of those strands. R-
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Old 06-04-2016, 01:07 PM   #23
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The first number is the number of strands, the second is the thickness (diameter) its my intention to use the wire in the link for a Bus and CDU connection red/black and blue/brown..
http://www.rapidonline.com/cables-co...ent-wire-75386
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Old 06-04-2016, 11:13 PM   #24
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Thankyou RogerB and Tinker for your replies. I'm almost embarrassed to admit that something so simple was baffling me.

Now, if someone can address the second part of my question about adopting a "one size fits all" approach for everything other than the bus(es), I'd be most grateful.
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Old 06-04-2016, 11:21 PM   #25
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The main two wires used in model railways are 7/0.2mm and 16/0.2mm

For a DCC bus I recommend 32/0.2mm as a minimum.

7 strand wires are manly used for DC track feeds, lighting, colour light signal feeds, stall type point motors and other low current applications up to around 1.2 Amp maximum.
16 strand wire is ideal for solinoid point motor operation and return, dropper wires rail to DCC bus and lighting bus wires up to around 3.0 Amp.
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Old 07-04-2016, 01:24 AM   #26
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Quote:
Originally Posted by Flashbang View Post
The main two wires used in model railways are 7/0.2mm and 16/0.2mm

For a DCC bus I recommend 32/0.2mm as a minimum.

7 strand wires are manly used for DC track feeds, lighting, colour light signal feeds, stall type point motors and other low current applications up to around 1.2 Amp maximum.
16 strand wire is ideal for solinoid point motor operation and return, dropper wires rail to DCC bus and lighting bus wires up to around 3.0 Amp.
Thanks for that FB. I'd already all but decided on 2.5mm2 stranded household cable for the buses - available in a multitude of colours from my friendly neighbourhood electrical wholesalers - because my layout will be 33'x8' I thought a bit of overkill might be prudent. If I've understood you correctly it would seem that using 16/02mm for everything else should be fine. I'm undecided on point motors but assuming I use solenoid type and bearing in mind the furthest points could be 40' from the control panel would 16/02 still be sufficient?
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Old 07-04-2016, 10:16 AM   #27
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Hi
40 ft is pushing the limits of 16/0.2mm for solenoid motors. Better IMO for reliable 100% operation would be to use 24/0.2mm or even 32/0.2mm or perhaps even double up on the 16/0.2mm for all three wires?

However as you're a DCC user (you say you have a 2.5mm2 bus pair - which is fine BTW) have you considered using DCC accessory decoders that can also have conventional switch operation too? Like for example the DCC Concepts AD-S2fx or AD-S8fx. These take their power from the DCC bus pair of wires (Very low current used) and are located nearby to the motors they are to operate. Short lengths of 16/0.2mm wire connect the decoder to solenoid motor. You're then guaranteed a reliable point motor operation each time. Note the DCC Concepts solenoid decoders have one CDU per output rather than some which only have one CDU for all outputs.
The control panel mounted manual switches only need a small gauge of wire to allow operation, so even 7/0.2mm will be fine in this case as they are only operating some electronics rather than a solenoid coil.
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Old 08-04-2016, 01:04 AM   #28
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Once again FB you have provided invaluable information that has expanded my (and I suspect, others) knowledge base considerably - for which I thank you.

Yes I have decided on the DCC route - there are too many advantages not to IMO - but for loco control only, not accessories. Why? Partly because I don't like putting all my eggs in one basket and having everything controlled by one unit. But particularly (in the case of points), I can't see me being happy with having to first call up a specific decoder address and then throw the point - far too involved and fiddly. To address this I've been toying with the idea of running a second bus pair purely for point motor power supply and have been wrestling with how best to switch that power. I wasn't aware that manually activated decoders existed so your suggestion may just supply the solution. Thanks again.

BTW, is the momentary contact (required by solenoid motors) provided by the accessories decoder or the manual switch? Also what is the operating voltage range of the decoders? Sorry to throw another couple of questions your way, just another idea I'm working on.
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Last edited by Cilfan; 08-04-2016 at 02:32 AM. Reason: Addition of BTW paragraph
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Old 08-04-2016, 08:33 AM   #29
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Instead of using a DCC accessory decoder to operate the points manually from a distance, you could use a couple of relays per point motor. I would think it would work out rather less expensive.
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Old 08-04-2016, 10:40 AM   #30
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Quote:
Originally Posted by Cilfan View Post
<Snip>
BTW, is the momentary contact (required by solenoid motors) provided by the accessories decoder or the manual switch? Also what is the operating voltage range of the decoders? Sorry to throw another couple of questions your way, just another idea I'm working on.
Hi

The momentary high power pulse of power to the point motor comes from the decoders electronics not any switch. A momentary switch can also used to operate the decoder manually but that only passes low current to the decoders electronics..

The DCC Concepts point decoders AD-S2fx or AD-S8fx use can be operated by either the DCC system or directly from a panel mounted momentary contact switch, or a press to make Push Button. This then operates the DCC decoder from a panel operating the point motor as normal. As stated above only low current is passed via the PB or switch hence 7/0.2mm wire can be used to run back to the decoder from the panel switch. The decoder also offers frog polarity switching for Electrofrog point users and LED indications for panel indications.

Their operating voltage is taken from the DCC track power which is 12~16v which is the norm for most DCC systems rail power. Link to leaflet

As suggested by Rog above a couple of suitable relays would operate the point motors remotely but you then you might need to add a CDU to their operation?
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