Is 22 gauge wire ok to use for siding on/off switches.
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Maybe. How much current is running through it?
@LIONEL40 posted:Is 22 gauge wire ok to use for siding on/off switches.
Not in my opinion! Wire size carrying track power, should be no smaller that 16 gauge, in my opinion.
No more than 18v from z4000
@LIONEL40 posted:No more than 18v from z4000
The voltage is not the issue/concern, but the current, i.e. AMPS. Thus, how much current will you be putting through it?
The current is sort of like how many gallons per minute you can transfer through a hose (the hose is like the wire). So forcing 3 amps through 22 gauge wire causes overflow and the wire will get hot. That's like bursting the pipe.
I would say no. Go for 14 or 16 gauge.
Fun fact: an amp IS a rate of flow. It's a coulomb per second. I just couldn't tell you what a coulomb is 
Concur with BillYo. On my 38x16 layout, only 14-gauge for track power. I built a layout for grandchildren, where longest run is about 5', and used 16. Don't skimp on wire gauge.
@LIONEL40 posted:Is 22 gauge wire ok to use for siding on/off switches.
No. Way too small.
Those wires are carrying current to run locomotives. You need at least 16 gauge wire to properly and safely do this.
The voltage is irrelevant.
I'm an ME, not an EE, so keep that in mind. But I thought we were sizing our wires more to prevent voltage loss over distance (which would cause locos to run slower in areas further from power source) versus a true carrying capacity of the wires?
The pickup wires inside our locos are definitely not 16ga, they look to me to be closer to 20. So why aren't they melting?
When we do trains, we're not really bundling lots of wires tightly together, to and they generally have pretty good exposure to air under our tables. We also don't necessarily run at full amps all of the time, so that helps.
Based on stuff we researched, using 18 or even 20 gauge wire to run power to the tracks is not going to be a safety problem for most folks. This website shows that 20 AWG copper wire with PVC insulation and not bundled tightly with more than 3 other wires could safely handle more than 10 amps.
However, we also found out that, even if the wires aren't going to melt, the drop in voltage over a long run to our furthest power districts did create a really aggravating slow down.
So my take is, don't sweat it if you're using 22ga wire for a short little run to a siding that will only be on for a minute at a time (it can safely carry 8 amps). But if it's far from your transformer, you'll be dialing the voltage way up to push the engine into the siding.
Also, this is assuming you have a fuse or breaker that will pop before your wire does in the case of a short or derailment. So just make sure your 22 gauge wire isn't it's own fuse, and something is in the circuit that will pop at much more than double the expected draw (6 amp maybe?)
Easier to do what these guys are saying and use 16 or at least 18ga from the get-go. The dude who is using 14 gauge probably has several long runs or maybe runs many locos at one on the same feed (I'm a conventional guy, DCS can change things since you're possibly running many locos together and tripling or quadrupling the draws that we have on our little layout). Otherwise 14 ga is pretty hefty stuff and maybe overkill for most of us.
@Jeff_the_Coaster_Guy posted:I'm an ME, not an EE, so keep that in mind. But I thought we were sizing our wires more to prevent voltage loss over distance (which would cause locos to run slower in areas further from power source) versus a true carrying capacity of the wires?
The pickup wires inside our locos are definitely not 16ga, they look to me to be closer to 20. So why aren't they melting?
Because those wires are not carrying all that high current.
When we do trains, we're not really bundling lots of wires tightly together, to and they generally have pretty good exposure to air under our tables. We also don't necessarily run at full amps all of the time, so that helps.
What if the operator is running a multiple set of powered diesel units pulling a passenger train with lights? Possible total current draw to that track section could be as high as 8 or 9 amps.
Based on stuff we researched, using 18 or even 20 gauge wire to run power to the tracks is not going to be a safety problem for most folks.
It isn't really a matter of "safety", but a matter of not having the wiring be the weakest link, i.e. the fuse, between the power supply and the center rail.
This website shows that 20 AWG copper wire with PVC insulation and not bundled tightly with more than 3 other wires could safely handle more than 10 amps.
Don't know what that "website" is, but if you are using MTH DCS, then solid copper wire should NOT be used! It is best to use stranded wire for layouts with MTH DCS.
However, we also found out that, even if the wires aren't going to melt, the drop in voltage over a long run to our furthest power districts did create a really aggravating slow down.
So my take is, don't sweat it if you're using 22ga wire for a short little run to a siding that will only be on for a minute at a time (it can safely carry 8 amps). But if it's far from your transformer, you'll be dialing the voltage way up to push the engine into the siding.
Also, this is assuming you have a fuse or breaker that will pop before your wire does in the case of a short or derailment. So just make sure your 22 gauge wire isn't it's own fuse, and something is in the circuit that will pop at much more than double the expected draw (6 amp maybe?)
Easier to do what these guys are saying and use 16 or at least 18ga from the get-go. The dude who is using 14 gauge probably has several long runs or maybe runs many locos at one on the same feed (I'm a conventional guy, DCS can charge things since you're possibly running many locos together and tripling or quadrupling the draws that we have on our little layout). Otherwise 14 ga is pretty hefty stuff and maybe overkill for most of us.
@Hot Water: for some reason I can't figure out how to hyperlink properly on mobile. The site I used is here:
https://www.multicable.com/res...f-copper-conductors/
I'm not familiar with the rules for DCS, but I think those figures are valid for either stranded or solid wire.
I get that running giant consists with multiple locos for extended sessions can affect wire choices, but OP specifically asked about a siding switch. That leads me to believe that those wires will not be carrying more than a single trains' worth of current for a very short period of time.
I agree about making sure that your wire isn't acting as the fuse. I mentioned that in my post (as well as the DCS disclaimer).
If you want to run smaller gauge wires to a toggle switch that’s fine. Just use them to control a relay that controls power to the rails. This will eliminate long runs of 14 or 16 gauge wire to a control panel and back to the rails. Use the relay contacts to control the break in the wire feed for track power. Lighter gauge such as 22 from the toggle to the relays coil.
Check this out. All you need to know about getting started. DCS and tmcc have there manuals with specific needs
