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Cable 'Routing'


Brian c

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Posted

Due to "public" :realmad: opinion I digged out a cable that might be accepted by you all :D ..

KJAAM 2x(2+1)x0,5 + 0,5 --> Two twisted pairs, each pair screened + common screening around both.. :w00t: 80pF/km capasitance (only 15pF more than in MHS) :rolleyes:

I hereby promise to try this out :yes: .

Tell me is it expensive if the price is 0,77

Posted

This is all very interesting but I can't help feeling that whatever you do or don't use in Finland - the whole of the UK uses stranded alarm cable!

Are you telling me that we as a country are wrong and that we havn't yet managed to work it out that we've been using the wrong cable for all these years and that is why we have false alarms?

Do me a favour - can you let ACPO in on this secret and then we can get all the regs rewritten??

Posted
This is all very interesting but I can't help feeling that whatever you do or don't use in Finland - the whole of the UK uses stranded alarm cable!

Are you telling me that we as a country are wrong and that we havn't yet managed to work it out that we've been using the wrong cable for all these years and that is why we have false alarms?

Do me a favour - can you let ACPO in on this secret and then we can get all the regs rewritten??

25941[/snapback]

As mentioned before, we use also different alarm systems in Finland and Electricity regulations are different here. Also alarm cable you use there is OK in small systems. Stranding is NOT the point ( I personally prefer stranded ). I am not the guy who wants to have several different kind of cables that is specially made for special purpose. Thats why I prefer multipurpose cable.

FA:s caused by induction can be reduced by using screened cable. This doesn't help if the panel casing is earthed because there is ALWAYS leak current in mains that comes back in earthing core. This is also noise and when using screened cables screening actually is emitting this noise to the other cores in the cable.

This I prevent by NOT earthing any metal parts in alarm system. This is OK with Finnish regulations IF safety voltage is used AND safety voltage is transformed by safety isolated transformer.

I am not saying that somebody is wrong. You have your regulations and if they do not allow installations the way I suggest them to be made then you have to live with those regulations. Regulations in electricity are usually made to save lifes. Sometimes they are more protective sometimes less protective. But those are the regulations we have to live with. In two different countries things are made differently. It is impossible to say that other way is better than other. Sure there is good things in both and something you can do better. Why not to learn? I have done testing and noticed in practise that this way it works, just sharing this with you all as many of you have already shared their knowledge to me. Or should I just sit here and be silent?

Posted

Noted, however my point is that in this country there is a special cable for alarm systems and regardless of the system size we are dictated to that this is the cable we have to use (with the exception of some systems datalines for keypads/nodes etc).

I certainly don't want you to sit back and be silent but on the other hand there is no point in spending 2 pages trying to sway the way we think because whether we like it or not we have to use alarm cable.

On the same topic does anyone know what the new EN regs say re cable type??

Posted

Does anyone else find themselves reading georgahti's posts with a Finish accent or is it just me.

Jef

Customers!

Posted

It would also be interesting if regualtions say that it should not be:

1) twisted pair

2) screened

Posted
Does anyone else find themselves reading georgahti's posts with a Finish accent or is it just me.

:w00t::w00t::w00t:

Mark Hawks

Ex BT Openreach Field Service

Now Self employed telecom and data engineer  www.mphtelecom.co.uk 

Also back doing sub contract work in the security industry.

Retained firefighter Devon and Somerset Fire and Rescue

Posted
Does anyone else find themselves reading georgahti's posts with a Finish accent or is it just me.

Jef

25959[/snapback]

I do but eventhough I am Finnish I am not yet Finish.. :lol:

Guest Rapid Racer
Posted
Does anyone else find themselves reading georgahti's posts with a Finish accent or is it just me.

Jef

LMAO :w00t:

I will from now on!

Georgahti,

I had big problems with a takeover job recently where the system was wired in solid core cable, mainly in the panel with the tampers where they were joined in a strip of terminal block. Each time I tried to close the lid on the panel another cable would break off. This simply doesn't happen with stranded cable. Does this happen to you?

Posted
Does anyone else find themselves reading georgahti's posts with a Finish accent or is it just me.

Jef

25959[/snapback]

:lol::):lol:

Mine keeps bordering on German

If you don't know......ask.

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