can I use CAT5 for temp probes and out's

Discussion of the physical aspects
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rcrabb22
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can I use CAT5 for temp probes and out's

Post by rcrabb22 »

I am using cscade's fermentation/refrigerator build as a guide and my BCS-460 is also controlling my kegerator which are located in separate areas of my basement.. Hence I have my BCS-460 centrally located.

I would like to use CAT5 cable for the 2 temp probes and 2 SSRs needed between the BCS and the chamber and 4 wire phone line for the 1 temp probe and 1 SSR between the BCS and the kegerator for neat and simple cable management. Do I need to worry about wire resistance (I'm a real newbie on this !!)

Thanks!
np0x
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Re: can I use CAT5 for temp probes and out's

Post by np0x »

I have done this with immunity in the past. You can find the information about how much additional resistance the wire adds to the circuit, but when you look at the tables and realize that the thermoresistors are 10,000 ohms, you rapidly realize you can wire to your hearts content.

The wiki isn't super specific about this but there is a quote saying to feel free to extend:
When wiring the temperature probes the polarity of the sensor wires is not relevant, the thermistors work equally well in either orientation. Connect one wire to the TEMP terminal, and the other to GND. Additionally extending the length of the temperature probes can easily be done due to the minimal resistance the extra wire adds to the circuit, so extending a probe to have a 20 foot (or more) lead can be done without impacting the accuracy of the thermometer.
clipped from: http://www.embeddedcontrolconcepts.com/ ... =Main_Page

I have gone 3x this length with no ill effects.

If you google about you see the ohms for the wire(I guessed 32 gauge) are less than a single ohm for 1000 feet.

http://www.powerstream.com/Wire_Size.htm
Check out the Brew Buddy for iphone controlling your bcs-460.
rcrabb22
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Re: can I use CAT5 for temp probes and out's

Post by rcrabb22 »

Thanks for the help. Time to start running the cables!
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