CAT-5 for doorbell?l


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Old 01-02-12, 09:03 PM
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CAT-5 for doorbell?l

I already have a roll of CAT-5 cable at home, can I use this for a new doorbell install?
 
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Old 01-02-12, 09:25 PM
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Sure. I always twin a pair for each conductor. Example: blue/blue-white twisted together as a single conductor and red/red-white twisted together as the second conductor.
 
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Old 01-03-12, 10:57 AM
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Not if you are using 120 volts. 12, 24 v is OK.....
 
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Old 01-03-12, 11:42 AM
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I would run regular thermostat wiring. Phone cable is only 24 gauge.
 
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Old 01-03-12, 02:57 PM
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I would run regular thermostat wiring. Phone cable is only 24 gauge.


Read more: http://www.doityourself.com/forum/ne...#ixzz1iRzjPkOu
I thought 24AWG was good for 1 amp? (at 24v)
 
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Old 01-03-12, 04:51 PM
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I was looking at it from a voltage drop perspective. When you only start out at 12 volts it is critical to minimize your loses.
 
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Old 01-03-12, 06:57 PM
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I've run into a couple of situations where I've thought fusing the secondary on the transformer would have been a good idea to protect the downstream wire, which is typically 18 AWG. That would be even more of a concern with 24 AWG.

One 24 AWG conductor has a cross-sectional area of 0.205 sq mm, so two would be 0.410, right? That's the same as 21 AWG. 18 AWG is 0.823 sq mm.

For my doorbell wiring I used 16 AWG, which is 1.31 sq mm.

Questions for somebody with more knowledge:

1. If the (30, 40, or 50VA) doorbell transformer is shorted at the far end of the secondary circuit, what AWG wire is needed to allow the unfused secondary of the transformer to fry itself, without damaging the conductors & insulation of the secondary circuit?

2. What size fuses should protect 24, 22, 20, 18, and 16 AWG?

Area source:
https://en.wikipedia.org/wiki/American_wire_gauge
 
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Old 01-03-12, 07:53 PM
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I believe regular bell wire used to be available, but most often I used to see 18 gauge thermostat cables used for door bell wiring.
 
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Old 01-05-12, 07:51 AM
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Choose a fuse for the transformer secondary to match the output of the transformer, for example a 50 va transformer with a 24 volt output will deliver 2 amps so use a 2 amp fuse.
 
 

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