[?] Gauge of wire on Lionel O-22 turnout levers?

[Birds]

Does anyone know what gauge the three wires are on the levers for Lionel's O-22 switches?

The ends I want to crimp on them come in sizes to fit either 18-22, or 24-30.

I don't have the tools to determine an accurate size.

Thank you,

Chris 

 

[lionelsoni]

I measured two samples.  Each had 10 strands, one of .005-inch diameter, one .006-inch diameter, which works out to 26 AWG and 24 AWG respectively.

[Birds]

Bob,

Thank you very very much.  This explains why some of my 18-22 gauge spade ends pulled out a bit even with the wire doubled over.

So, one should be fine using multi-line phone, or network, wire as these are usually 24-26 gauge?

I have several location where two or three switches are clustered together.  Being able to use multi-pair wire would greatly simplify the installation, provide some color coding for connections, and make for a much cleaner look.

Thank you again.

Chris

[lionelsoni]

You could.  I like 18-10 solid thermostat cable for that sort of thing.  

[ben10ben]

If you do use telephone wire, I'd suggest saving yourself some headache and using insulation piercing spade lugs.

They're available from Radio Shack and plenty of online sources. 

In my experience, telephone wire is typically very hard to strip, and the problems is often increased by the fact that it's often interwoven with cotton thread(presumably to offer increased flexibility). 

The insulation piercing spades save having to strip the telephone wire, plus are pretty much immune from slipping off of the wire as can sometimes happen with conventional crimp-on spades. 

I go through a lot of insulation piercing spades in working with the telephones in my collection-I wouldn't wire telephones any other way. 

By the way, I use "intercom wire" from Radio Shack for wiring my switches and UCS tracks. It's a 22-gauge solid, paired wire. I find it ideal for these applications since it's cheap, and you really only need to actually run two wires to a switch or UCS track anyway.

[Birds]

Bob and Ben,

Thank you both very much.

Am I correct in thinking that 24 gauge wire can safely handle a load up to 3.5 amps?

Will the lamps on the lever control still function if I decide not to run the middle common/ground wire from the switch levers on the control board to the middle post of the turnouts on the table, but instead tie the middle wires of the levers to a common/ground buss bar within the control board itself?

This would be one less wire running from the control board to the table for each turnout used.  So with 11 turnouts thats 22 fewer connections between the table and board.  Or 44 fewer connections if one has plugs at the table, plugs at the board, and uses a connector cable between them.

Thank you.

Chris

[lionelsoni]

More like 2.5 amperes continuously; but a turnout controller should only be operated for a second or so.

Here's an easy way to estimate wire ampacity:  The NEC generally allows 10 AWG to carry 30 amperes, 12 AWG to carry 20 amperes, and 14 AWG to carry 15 amperes.  In theory, when electrical and thermal resistivity are taken into account, ampacity doubles every 4 AWG wire sizes.  So since 24 AWG is 12 sizes smaller than 12 AWG, its ampacity is 20 amperes halved 3 times, or 2.5 amperes.  This is a very rough estimate and doesn't allow for type of insulation and bundling of wires (which reduces their ampacity); but it's better than nothing.

Indeed you can get your common directly from the transformer, or an outside rail or any other point connected to the transformer common.

[Birds]

Bob,

Thank you.  That's a helpful way of working with amp ratings.

 

Do you have any estimates how much 4 pair 24 gauge bundled wire might reduce the amp capacity?

 

• Control lever lamp = .25 amps
• Throwing a turnout = .8 amps
• Maximum current accross control wire = 1.05 amps

 

I realize throwing a turnout is a quick event, but I still want to make sure I don't overload/overheat the wiring bundle.  At the same time I don't want to over wire if it's not needed.

 

Thank you,

Chris

[lionelsoni]

The NEC derates ampacity to 80 percent for 4 to 6 wires, 70 percent for 7 to 9 wires (your case), 50 percent for 10 to 20 wires, 45 percent for 21 to 30 wires, 40 percent for 31 to 40 wires, and to 35 percent above that.

The maximum current in your control-wire example is .8 amperes.  The controller lamp draws no current while the turnout is being thrown.  However, it is not reasonable to assume that that current flows other than briefly.  Either a turnout like an 022, for example, will shut the current off after it throws or the coil of a turnout like a 5122, for example, will burn up if you hold the lever.

[Birds]

Bob,

Thank you.

 

So what I understand from your explainations is:

• single 24 gauge wire will carry 2.5 amperes
• four pair 24 gauge wire is derated to 70% ampacity, so it is rated at 1.75 amperes
• the sustained current accross the control wire will be .25 amperes for the lamp on the lever
  
• when a turnout is thrown the control wire will carry a brief spike of .8 amperes (amount based upon my testing with a VOM)

Thank you again for your time and patience.

 

Chris 

[ADCX Rob]

Birds

...Will the lamps on the lever control still function if I decide not to run the middle common/ground wire from the switch levers on the control board to the middle post of the turnouts on the table, but instead tie the middle wires of the levers to a common/ground buss bar within the control board itself?

This would be one less wire running from the control board to the table for each turnout used.  So with 11 turnouts thats 22 fewer connections between the table and board.  Or 44 fewer connections if one has plugs at the table, plugs at the board, and uses a connector cable between them.

Or, you could reverse your thinking, and consider that you might want to tie the middle wires of the levers to a common/ground buss bar within the control board and run/leave the middle common/ground wire from the switch levers on the control board to the middle post of the turnouts.  This would quite possibly eliminate the need for several outside rail power drops around the layout.

Or go even one step beyond, and instead of using the Lionel 711-151 constant voltage plug on the switch, use a coaxial power plug from Radio Shack.  Wire the sleeve to the track voltage output, & the tip to the switch constant voltage. 

Instead of being a layout weak spot in current continuity, these steps will make the 022(or 711, or 721, or their clones) an actual power source, much like a hard-wired lockon.

Rob 

[lionelsoni]

Be sure that the feeders that Rob is suggesting are heavy enough for the track current.  That is, don't use the 24 AWG wire in the controller cable for this purpose.

[ADCX Rob]

There would be enough redundancy in the outside rail feed in a layout this size that I would have no problem with 24 AWG wire.  I do it with 24 AWG for the center rail feed with several(~6-8) remote switches on the Christmas layout & no lockons at all(powering entire layout - ~200 feet of track).

Rob 

[lionelsoni]

I sure have a problem with it.  The whole point of multiple feeders is to get the current to the track without relying on the conductivity of the rails.  If the 24 AWG feeders are not burning out, the rails must be doing a pretty good conduction job to share the load among the feeders and probably could distribute the current around the layout on their own.  Track resistivity is highly variable, but is roughly equivalent to 16 AWG, which has only about one-sixth the resistivity of 24 AWG wire.

[Birds]

Rob,

 

Thank you for the suggestions.  Interesting solutions.

 

Given my basic understanding of electricity, I think I'll stick with the three control wires going to the turnouts and avoid getting fancy.  It's more crimping, but I know everything will work and I'll be able to trace the wires more easily.

 

Chris