Cable, Points and Control Panel

[sjrixon]

Hi all!

 

I'm looking to do some shopping for a few drums of cable for point motors. eHattons do 100m drums for £7.50.

 

http://www.ehattons.com/43434/Expo_Drills_Tools_22021_100m_Drum_18_Strand_Cable_Black_Outside_Diameter_1_0mm/StockDetail.aspx

 

Appears they have a few colours.. This would keep me in cable for years.. 

 

Any other options?

 

I can't find anything like this on Maplin and RS were about £17 for something similar.

[cliff park]

First thoughts ? I'm not sure that this is heavy enough for your intended use. It doesn't state size of strands, or current carrying capacity, but with an outside diameter of 1mm this would appear to be very small.

[Crosland]

What sort of point motors? That's way too thin for reliable operation of solenoids, in the general case, and you should be looking at something more like http://www.rapidonline.com/cables-connectors/rapid-32-0-2mm-equipment-wire-1500v-6a-6232532 strands of 0.2mm.

 

Solenoid motors take a hefty pulse of current which, combined with the resistance fo the cable, causes a loss of voltage to the motor.

 

Whether it works well will depend on the voltage you use, the solenoids and the length of the connections.

[sjrixon]

From Expo's web site

 

220-20
RED 18 strand cable ideal for wiring
Model Railways & similar applications:
Rated: 1.4A @ 1000v Max
Outside Diameter: 1.0mm

 

Gaugemaster PM1 point motors. 

 

I thought it was too cheap!

[Suzie]

Try Rapid. They have a pack of eleven reels of 7/02 wire in different colours:-

 

http://www.rapidonline.com/cables-connectors/equipment-wire-7-0-2-11-reels-of-100m-01-0480

 

You might need a few reels of fatter wire as well if you are wiring up solenoid point motors (a tip is to use the PL10W which don't need fat wire).

[sjrixon]

I read that Guagemaster recommend 1Amp for the PM1 motor.. So you shouldn't need any fatter wire for the solenoid. Their point control box only provides 1amp.

 

http://www.ehattons.com/8997/Gaugemaster_Controls_PCU1_Electronic_points_control_unit/StockDetail.aspx

[Gordon H]

I read that Guagemaster recommend 1Amp for the PM1 motor.. So you shouldn't need any fatter wire for the solenoid. Their point control box only provides 1amp.

 

http://www.ehattons.com/8997/Gaugemaster_Controls_PCU1_Electronic_points_control_unit/StockDetail.aspx

In this instance, it's not about whether the wire can carry the current the control box provides (which sounds a bit feeble at 1A anyway) but more about voltage drop it causes due to the additional series resistance.

Thicker wires mean that more of the available power ends up doing useful work at the motor, not being partially lost in the wires that connect it.

[Crosland]

From my reading of the PCU1 data sheet, the 1A refers to the aux output. This unit includes a CDU (that's a good thing) and should give a nice hefty pulse of current when operating.

 

The PM1 data sheet makes no mention of the maximum current.

 

Please listen to the advice being given re. wiring

[sjrixon]

I'm listening

 

I thought this was going to be more of a black and white answer! For point motors I would use X...

 

If 7/02 from Rapid isn't enough, then how about this?

 

http://www.brimal.co.uk/index.php/online-shop?page=shop.product_details&flypage=eny_fly_brimal.tpl&product_id=1077&category_id=477

 

That's rated up to 3.0A and I clicked the link on the RMWeb page! Go advertising.. 

[Gordon H]

Unfortunately for many, there is rarely a black/white 'one size fits all' solution for all circumstances.

Yes, in most cases you would be able to use 16/0.2 for solenoids.

However, your decision sequence could be expanded somewhat to incorporate some calculations, all of which relate to basic Ohm's Law :

For Point Motor Type W, at Distance X, with Supply Voltage Y, I would use Wire Z.

From this you can get an idea of how much of your available power will end up at the motor.

[Suzie]

You will probably save enough on the wire if you buy PL10W or PL10EW point motors (which will allow you to use 7/02 wire for the point motors) to justify using them exclusively. The significant improvement in efficiency will make a big difference all round, thinner wires are much easier to manage.

[sjrixon]

Ah.. But I want to use the switch to do polarity switching on the point..

 

I think I can wire the power for the soliend with the fatter wire and the rest with the thin.. Job done

[Crosland]

You can fit the switches to either type of motor, can't you? Some people report these as being quite fiddly to adjust.

 

Thinner wire is fine for the frog polarity switching as it will only be a few inches with minimal voltage drop.

[sjrixon]

The PM-1 it's built in.

[14Steve14]

In my opinion the 7/0,2 wire is a bit small for solenoid point motors regardless of make. It will be fine if you are planning to use LEDs to show which way the point is facing though.

 

For any type of point motor wiring I always recommend to my customers that 16/0.2 should be used. It will be large enough to prevent too much voltage drop and will handle the current from any capacitor discharge unit. It will also be large enough should you operate several points at the same time. If you are not planning on installing one of these units use the larger wire any way, as it will allow you to fit one should you wish at a later date.

 

If you are planning to use a common positive or negative you can go up a size and use 24/0.2 if you wish.

[phoenix160]

i would also recommend 16/0.2,  we have used this on solenoid point motors in a diode matrix firing up to six p/m's at once pushing a gaugemaster CDU up to 24 volt A.C.  All works fine.

[RAF96]

Just to throw the cat in amongst the pigeons...

 

I use stripped out network cable. It is solid cored and liable to fracture if moved about a few times. Its also too thin a gauge for solenoids, so I use 2 strands twisted together, but I revert to single strands for leds and associated switch wiring.

 

I know its agin all known best wiring practice (multi-strand and hefty wires) but it was all I had at the time and it worked then and it still works now 5 years later with nary a failure yet..

 

Waiting for the flak...

[14Steve14]

If its all you had and it works that's fine. If your solid core cable is well supported and cant move, the chances are it will not break.

 

From what I can gather there is no right or wrong way of wiring a layout. Every article you read on the internet from reputed experts say different things, which people find confusing. Most ways work, so its really up to the layout builder.

 

As the hobby is expensive I am all for the 'if you have it use it' policy, as long as it works and is safe.

[LJB]

Keep your eye open for house refurbishment works and ask for any old (red and black) house wiring. So long as you don't ask for too much the builders will probably let you have some free. It can be stripped fairly easily. All you need then is a drum of cable clips (Maplin sells 1000 in assorted colours for < £10) which can be used to colour-code everything. Alternatively a metal recycling place might be amenable to letting you have some old wire for the price of the copper - much cheaper than bought reels of any description. This is all I have used for my heavy current wiring.

Network cable is of two types, solid cored and stranded, but provided it is well supported I have never experienced any problems with using it for signalling purposes - and that on a dismantleable layout.

Another option is old transformer wire. Pull transformers out of old video players and the like and you get an almost endless supply of insulated wire. If the transformer is one with a laminated core just give the core a couple of small clouts to separate the laminations and then pull the core apart. This gives the wire as convenient coils. With a reasonably hot soldering iron the varnish on the stuff is also self-fluxing - that one's a real bonus. I have wired up a complete control panel like this. It's a total rat's nest, so don't ask me for pics, but it works!

[28XX]

Consider also loudspeaker twin cable, one core for points normal, one for reverse. The common connection of the point motor can be looped in a ring main or attached to a bus depending on the physical shape of your layout. 16/0.2 or larger as recommended above.

[sjrixon]

Speaker cable I've used a lot of! When needing some quickly was the best value I could find. So most of my controllers were wired in with speaker cable.