Wire question for long run

[EL34]

I have to make a 150ft wire run to some DS1820 temp sensors inside some schedule 40 gray pvc pipe.
I am powering the sensors from my 6 channel master hub at the other end of the cable.

I was going to use some spare cat 6 cable I had here already but it seems like such a waste to use such nice cable.

Telephone cable spools are so cheap, but not shielded like the cat 6.

I need 3 wires for the sensors, is telephone cable useable in this situation?

 

[ericvic]

I have to make a 150ft wire run to some DS1820 temp sensors inside some schedule 40 gray pvc pipe.
I am powering the sensors from my 6 channel master hub at the other end of the cable.

I was going to use some spare cat 6 cable I had here already but it seems like such a waste to use such nice cable.

Telephone cable spools are so cheap, but not shielded like the cat 6.

I need 3 wires for the sensors, is telephone cable useable in this situation?

I would not use telephone cable. It is the twists in CAT5 that make it work correctly and telephone cable either has no twists at all or not the right number. I know it seems like a waste to use CAT5 but I have heard many stories where someone tried to use telephone cable and ended up having to go back and replace it with CAT5.

Eric

 

[Michael McSharry]

I do not know the technology of a Cat6 vs. Cat5 cable, but for longer runs your objective is to keep the capacitance of the cable low. Typically a better "shield" also makes a bigger capacitor. If you run 3 wires then leave both ends of the other 5 disconnected for this same reason. The twists in the Cat5 will give you the necessary noise immunity.

Eric is correct that use of Cat3, speaker wire, zip cord or other junk box occupants would be a poor choice.

 

[EL34]

Okey dokey guys. Thanks for the info.
The cat 6 I have is way nicer than plain ole cat 5

It has a super hard and stiff outer jacket so you can pull it through metal rafters, etc without damaging the cable and it is way stiffer than regular cat 5.
Each twisted pair inside rides in is own section of a + (plus) shaped plastic divider all the way down the cable.
This keeps the twisted pairs away from each other so you can run Gigabit lans.

See why I say that using this cable is pretty much overkill and sort of a waste.

I may stash this cable and get a spool of regular cat 5.

I also have a spool of 22ga - stranded - 3 wire - shielded cable that I made my DS1820 temp sensors with.
It has foil shield, but the wires inside are not twisted.
Twisted pairs work great for long runs on AC signal lines like phone.

Not sure if a DC signals like that used in One Wire stuff benefits from twisted pairs?
If so, I suppose the data line and the ground should be run through the twisted pair?
The 5 volt supply would be all by itself, not in a twisted pair.

 

[sda]

The 1-wire overview recommends twisted pair cable, usually cat3 or better for home size (about 400' run) network segments.

http://pdfserv.maxim-ic.com/en/an/app132.pdf
see page 3

If your conduit is underground, consider using outdoor rated cable. The conduit will fill with water from condensation.

 

[EL34]

Excellent,
Thank you for the info

 

[EL34]

Hehe, I figured out a way easier way to do my cable run.
Turns out, my total outside run was just under 100ft.

I wasn't aware you could purchase direct burial cat 5e cable with the gel goo inside.
I bought 100ft spool for $25.

I don't have to run schedule 40 pvc pipe.
This is so much easier just running a water proof cable.

 

[jasv]

Hehe, I figured out a way easier way to do my cable run.
Turns out, my total outside run was just under 100ft.

I wasn't aware you could purchase direct burial cat 5e cable with the gel goo inside.
I bought 100ft spool for $25.

I don't have to run schedule 40 pvc pipe.
This is so much easier just running a water proof cable.

Where did you get the gel goo cable? Does it have a name I could google?

 

[EL34]

http://www.cat5ecableguy.com/outdoor_bulk_cable?b=1
This guy will sell increments of 100ft, but it cost more that way.

1000ft spools are $155 at a few places on the web.

I only needed 100ft so I went with the guy above.

 

[EL34]

I received the direct burial cat5 wire.
Got my greenhouse hooked up with the new cable.
Reading three DS1820 temp sensors in the green house.

The cable is pretty nice stuff.
Has the usual 4 twisted pairs, plus a super tough outer jacket and it is filled with that sticky goo stuff for water proofing.

Just giving an update in case anyone is looking for a wire they can bury and forget.