Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.


2039 posts

Uber Geek
+1 received by user: 346

Trusted

Topic # 165517 12-Feb-2015 09:50
Send private message

I'm thinking about pre-wiring for a security alarm in the house and separate garage. I've glanced a few installer manuals but none have the basics of security alarm wiring.

I'll bury a run of PVC duct between the house and garage for ethernet and alarm cable.

I can't seem to find gel-flooded or otherwise exterior rated security cable - does it exist? I'm thinking of substituting alarm cable with gel-flooded Cat5e for the underground section of the run - Cat5e seems to have about half the conductor area per core (0.2mm2 versus 0.5mm2), so would bonding two Cat5e conductors together be a suitable substitute? This would give me the equivalent of a 4-core security cable on a single Cat5e cable. I'm assuming that standard alarm cable in a (inevetiably) water filled PVC duct is a bad idea

What's the difference between 4-core and 6-core alarm cable (other than the obvious!)? Seems like 2x power and 2x signal cores should be all that is necessary

I'm planning on having 1-2 PIRs in the garage and an external siren. Do sensor and alarm circuits need separate cables or can they be combined on a 6-core?


TIA

 

Nick

View this topic in a long page with up to 500 replies per page Create new topic
 1 | 2
7772 posts

Uber Geek
+1 received by user: 2563

Subscriber

  Reply # 1236320 12-Feb-2015 09:56
Send private message

just use Ethernet (cat5) for security cable. its more than suitable now days.

when my bro-in-law (alarm technician) did our garage each item (pir, siren) was on its own cat 5 cable.

2454 posts

Uber Geek
+1 received by user: 725

Trusted
Lifetime subscriber

  Reply # 1236325 12-Feb-2015 10:01
One person supports this post
Send private message

If you are anywhere near west Auckland let me know the approx length you require and I'll see if we have that much on the end of a roll of outdoor rated cable that we are unlikely to use.  The outdoor rated cable is a fraction more rugged and UV-resistant but is not gel filled.  If you are running through conduit you can probably use standard cable without issue.




"4 wheels move the body.  2 wheels move the soul."

“Don't believe anything you read on the net. Except this. Well, including this, I suppose.” Douglas Adams

21530 posts

Uber Geek
+1 received by user: 4384

Trusted
Subscriber

  Reply # 1236393 12-Feb-2015 11:13
Send private message

I wouldn't use standard cable in conduit going underground. Always seems to get water in it no matter how well glued the joins and we'll sealed the box at the end is.




Richard rich.ms

Hmm, what to write...
998 posts

Ultimate Geek
+1 received by user: 506

Trusted
Subscriber

  Reply # 1236397 12-Feb-2015 11:19
Send private message

One thing, Some security systems, (eg paradox) do not play nice with data cables running in close proximity. What normally happens is the cables all pass the tests ok but as soon as you power up the security system the data rate drops. Basically there is so much interference from the bus comms on the alarm system that the LAN packets keep getting dropped and resent.

If you use the cat 5 LAN cable for an analogue phone you can hear the pulses from the alarm system (sounds like a fast electric fence)

So what I am saying is even though it is perfectly legal to run your alarm cable with the data it is a bad idea. Run another conduit.

I'm quite sure others on here will say it doesn't cause a problem, but I have fixed enough to know that it does.








Matthew




2039 posts

Uber Geek
+1 received by user: 346

Trusted

  Reply # 1236398 12-Feb-2015 11:20
Send private message

Thanks for the input!

So sounds like I'll need two runs for PIR & siren @Jase

That's my concern @richms

Thanks for the generous offer @dynamic, but I'm in Christchurch. Where did you get such a cable from? I wouldn't mind buying a whole roll as it would be handy for other things like LED garden lights and irrigation solenoids



2039 posts

Uber Geek
+1 received by user: 346

Trusted

  Reply # 1236401 12-Feb-2015 11:26
Send private message

mdooher: One thing, Some security systems, (eg paradox) do not play nice with data cables running in close proximity. What normally happens is the cables all pass the tests ok but as soon as you power up the security system the data rate drops. Basically there is so much interference from the bus comms on the alarm system that the LAN packets keep getting dropped and resent.

If you use the cat 5 LAN cable for an analogue phone you can hear the pulses from the alarm system (sounds like a fast electric fence)

So what I am saying is even though it is perfectly legal to run your alarm cable with the data it is a bad idea. Run another conduit.

I'm quite sure others on here will say it doesn't cause a problem, but I have fixed enough to know that it does.



Good point - I've got shielded Cat5e (Ubiquiti tough cable) so hopefully this should mitigate interference between the cables. 2xCat5e would be dedicated to alarm systems and 1xCat5e for ethernet so there would be double shielding between each 'system'



2039 posts

Uber Geek
+1 received by user: 346

Trusted

  Reply # 1236404 12-Feb-2015 11:27
Send private message

Supplementary question: I've got a box of Ubiquiti Tough Cable carrier, which looks erm tough, but not actually direct burial rated. How do you guys think this will go in an underground conduit, taking water infiltration as a given

21530 posts

Uber Geek
+1 received by user: 4384

Trusted
Subscriber

  Reply # 1236408 12-Feb-2015 11:32
Send private message

Alarms comes to keypads isn't balanced so pairs make little sense for it.

Also talk to alarm person about an expander for the garage. When I priced it up wasn't too much more than pulling cable for all the separate things.




Richard rich.ms



2039 posts

Uber Geek
+1 received by user: 346

Trusted

  Reply # 1236658 12-Feb-2015 15:23
Send private message

richms: Alarms comes to keypads isn't balanced so pairs make little sense for it.

Also talk to alarm person about an expander for the garage. When I priced it up wasn't too much more than pulling cable for all the separate things.


Not worried about balancing it, more just providing enough current capacity given that Cat5e conductors are less than half as thick as alarm cable conductors.

It's only about 3 meters between the house and garage, and only 2 cables so probably cheaper to just go the 'dumb' approach

2454 posts

Uber Geek
+1 received by user: 725

Trusted
Lifetime subscriber

  Reply # 1236813 12-Feb-2015 20:29
Send private message

nickb800: Thanks for the generous offer @dynamic, but I'm in Christchurch. Where did you get such a cable from? I wouldn't mind buying a whole roll as it would be handy for other things like LED garden lights and irrigation solenoids

We use the Dynamix brand of cable - if you search dynamix gel you should see some results.  Anticipate $1.50 - $2.00 per meter for a 305m or 500m roll.  Some places might let you buy this or similar cable by the meter.  Dick Smith or Jaycar or PBTech are likely candidates.




"4 wheels move the body.  2 wheels move the soul."

“Don't believe anything you read on the net. Except this. Well, including this, I suppose.” Douglas Adams

3254 posts

Uber Geek
+1 received by user: 640

Trusted

  Reply # 1236818 12-Feb-2015 20:42
Send private message

My stepfather is an alarm installer.
He reckons that you shouldnt use cat5 cable for the alarm stuff because of its lower current carrying capability - the absolute maximum on a single copper core is 570 milliamps on cat5.
So they use 4-core alarm cable.
You can buy 100m rolls of it pretty cheap at ideal electrical.

I have asked him numerous times saying it would just be cheaper if they used cat5 because they could effectively patch two 4-wire smoke alarms or PIR sensors into the one cable between buildings.

He said they have had to re-wire cowboy installations after problems were found because some alarm systems also use resistance to send different signals so a cat5 cable with a higher resistance can cause mixed messages.




Ray Taylor
Taylor Broadband (rural hawkes bay)
www.ruralkiwi.com

There is no place like localhost
For my general guide to extending your wireless network Click Here




7772 posts

Uber Geek
+1 received by user: 2563

Subscriber

  Reply # 1236851 12-Feb-2015 21:33
One person supports this post
Send private message

if you do a google search there is a lot of different opinions but a lot of people say its fine for cat 5 for sensors/sirens etc. You may need a screened cable for the keypad though.

just looked up a standar Bosch PIR, and the requirements of it are 10mA @ 12vDC for power and 100mA @ 25vDC for the tamper/sensor side of things so well under your 570mA

an alarm panel draws 50mA max, so i really cant see any device in a system using 570mA except for the control panel, but then that is connected to the mains by mains rated cable not cat5

Im just saying the maths says there is no reason you couldn't use it.

2454 posts

Uber Geek
+1 received by user: 725

Trusted
Lifetime subscriber

  Reply # 1236852 12-Feb-2015 21:35
Send private message

raytaylor: My stepfather is an alarm installer.  He reckons that you shouldnt use cat5 cable...

Thanks Ray - I'll store that in the memory banks for future reference.




"4 wheels move the body.  2 wheels move the soul."

“Don't believe anything you read on the net. Except this. Well, including this, I suppose.” Douglas Adams

4468 posts

Uber Geek
+1 received by user: 2469

Trusted

  Reply # 1236905 13-Feb-2015 03:02
Send private message

Thread author: what type of conduit were you planning to use for your project?




Whatifthespacekeyhadneverbeeninvented?


5272 posts

Uber Geek
+1 received by user: 2287

Trusted
Lifetime subscriber

  Reply # 1236945 13-Feb-2015 08:38
Send private message

Any alarm systems out there that are built on IP? I.E. sensors, keypads etc. are all PoE capable Ethernet devices?




Chorus has spent $1.4 billion on making their xDSL broadband network faster. If your still stuck on ADSL or VDSL, why not spend from $150 on a master filter install to make sure you are getting the most out of your connection?
I install - Naked DSL, DSL Master Splitters, VoIP, data cabling and general computer support for home and small business.
Rural Broadband RBI installer for Ultimate Broadband and Full Flavour

 

Need help in Auckland, Waikato or BoP? Click my email button, or email me direct: [my user name] at geekzonemail dot com


 1 | 2
View this topic in a long page with up to 500 replies per page Create new topic

Twitter »

Follow us to receive Twitter updates when new discussions are posted in our forums:



Follow us to receive Twitter updates when news items and blogs are posted in our frontpage:



Follow us to receive Twitter updates when tech item prices are listed in our price comparison site:



Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.