Alarm sensor cable + cat5 cable through joist in same hole?

A bit of advice please.

I have a cat5 cable (2 twisted pairs screened) running through 16mm holes bored through the joists and I need to reroute 2 alarm sensor cables. I dont want to bore more holes in joists if they are not needed, can I run all 3 cables through the same holes without causing errors on either the alarm or the DSL running off the cat5.

There are no mains cables in these holes of course.

Better just add that the cat5 is being used as a 2 wire telephone extension for my DSL from the main BT socket to an extension socket elsware in the home.

should be fine becasue the cable is screened

Thanks, fingers crossed then.

cat5 cable is not screened!

rssteve said:

cat5 cable is not screened!

Click to expand...

Hmm, well its solid cores, 2 pair twisted with a foil screen and the lorrry driver who's tailgate it fell off told me it was cat5
I suppose the most important bit is will it do the job without talking to the alarm cable about where it came from!

I've cabled two factories with cat5. Despite everyone worrying, the only time I've had cat5 affected by other cable was when some muppet ran the refrigeration power supply down the cable runs that I'd put in. 120A a couple of mm away screwed it big time, but I've never seem many problems with smaller cables. I'm sure that the Cat5 will be unaffected by your alarm cable.

I'm equally sure the reverse is true. We bundled 100+ Cat5 cables with various alarm cables feeding into the IT room without any noticable cross contamination.

To reassure you, the twisted pair stuff comes in lots of flavours, including both screened and unscreened. In a home enviroment, the screening is unnecessary but harmless.

However there should be 4 twisted pairs with Cat5 (ie 8 wires), not 2.

Hehe, this gets stranger by the minute, ok Mr lorry driver where's my other 2 pairs gone!

As its only to extend the phone cable and I have got rid of the ringer wire I do only need 1 twisted pair, so I have a spare pair anyway

Seems my cat5 is cat 2.5 instead, but if it does the job I wont worry much, seems the opinions are that it will and wont cause the alarm to have kittens, so watch out holes in joists as you are about to be invaded by a couple of alarm cables as well as being host to a dubious grey cable with 2 twisted pairs and a foil screen

Thanks all.