Unshielded Or Shielded Alarm Cable?

[raveyard]

Hi,

I'm currently undertaking a major house renovation and need to plan for the install of my alarm cables.

The alarm base will be in a "technical room" in the cellar, along with the 240V AC consumer unit.

All electrical cables from the upper 2 floors of the house will run back through a shaft to this technical room, so both alarm cables and mains cables will be in the same shaft, although obviously in separate conduits.

At this stage I am not sure what physical separation, if any, is feasible between the mains cables and the alarm cables, hence my concern over induced EMI in the alarm cables. It will be the electrician installing the wires/conduits.

I will install the alarm panel myself, a Texecom Premier 48. I have previously (successfully!) installed a Texecom Veritas Excel in a previous house. I have a former background in electronic engineering.

So the questions are:

1. Should I use shielded alarm cable instead of unshielded to help prevent mains interference, or would unshielded be OK?

I am assuming (off the top of my head) the shielding needs to be all connected to each other at the alarm box and connected to earth?

Are there any other issues/problems with shielded cable I should be aware of?

2. 6-core or 8-core alarm cable? I used 6 core before, but I noticed on a few posts some are recommending 8-core and doubling up power cables.

Thanks in advance for any tips,

Richard

[PeterJames]

ideally you need to keep the cables as segregated as much as possible, screening can help only earth at the panel end. Doubling up the power cores is done to help current loss on long runs wont make any difference to emi, I would recommend you use 8 core though you never know if you are gonna need an extra detector somewhere

[MrHappy]

I'm currently undertaking a major house renovation and need to plan for the install of my alarm cables. I am not sure what physical separation, if any, is feasible between the mains cables and the alarm cables,

7671 requires you to keep selv away from low voltage, should you bodge everything together & cables get damaged you Can have low voltage items which are "live" of cables not rated for voltages present

[PeterJames]

Dave, He did say

obviously in separate conduits.

[raveyard]

Thanks guys,

Just as a P.S. ... the house is in France and the local price of an alarm is literally thousands of Euros, hence I'm going to support the UK economy and import and install a Texecom alarm from good old Blighty!

If I could just make it absolutely clear there will hopefully be no "bodging"! All the mains electrics will be done to norms by a reputable electrical firm, I was just a bit concerned there may be a section in the shaft to the basement where conduits carrying alarm cables may run alongside conduits carrying mains cables, and the obvious risk of EMI and possible false alarms.

So if I understand rightly, you do recommend shielded cable but I still need to try and separate the conduits as far as is physically possible. Maybe it would be possible to divide the shaft into 2 with a mains voltage and low voltage section (there will also be Cat 6 and TV/SAT coax cables running back down to the basement technical room too).

What sort of physical separation of mains AC from shielded alarm cable is advised for parallel conduits?

[Rulland]

When you say 'conduits', are we talking round type-metal/plastic, or do you mean cable trunking? again metal/plastic-imho if metal then major seperation isn't to big an issue as the metalwork will be earthed anyway (or should be!).

Just as an aside, there is a worlds difference between a Prem 48 and a Veritas Excell tbh,good luck

[raveyard]

When you say 'conduits', are we talking round type-metal/plastic, or do you mean cable trunking? again metal/plastic-imho if metal then major seperation isn't to big an issue as the metalwork will be earthed anyway (or should be!).

The conduits would definitely be round PLASTIC type. Here in France the metal ones are highly forbidden for mains voltages!

Yes, sadly if the cables were in grounded metal tubing then that shouldn't be an issue.

Although thanks for the idea... Maybe it would be possible to run the alarm cables in an earthed metal conduit though...???

Just as an aside, there is a worlds difference between a Prem 48 and a Veritas Excell tbh,good luck

As for the Premier 48, I was wanting between 8-16 zones and 2 Areas, hence the need for something a bit more capable the Veritas Excel.

I do have an Electronics Engineering/Computing background, so I'm pretty happy soldering and working my way through complex instructions as long as the manuals are comprehensive and correct.

Would it really be a bad idea to go down the Premier 48 route for a hopefully-competent DIY'er, or is there something else you would recommend?

(It's much easier to change my plans at this stage before I buy all the kit!)

[Rulland]

You could contain the alarm cables in metal conduit that would help-but again tbh the amount of installs I have seen where differing voltage cabling is not particularly segregated and the intruder stuff hasn't really suffered is suprising!-that doesn't make it right btw!.

If you want flexability and ease of progging etc then Prem is definately the way to go, very user/installer friendly although very powerful in terms of versatlity-hence where I made the point of progging comes in, how does it work in France as far as insurance etc with a diy instal even if it is a Prem!-you don't want to get bitten by the 'registered/affiliated' company type thing.

[sixwheeledbeast]

As for the Premier 48, I was wanting between 8-16 zones and 2 Areas, hence the need for something a bit more capable the Veritas Excel.

I do have an Electronics Engineering/Computing background, so I'm pretty happy soldering and working my way through complex instructions as long as the manuals are comprehensive and correct.

Would it really be a bad idea to go down the Premier 48 route for a hopefully-competent DIY'er, or is there something else you would recommend?

(It's much easier to change my plans at this stage before I buy all the kit!)

Bear in mind Premier Series panels are aimed for the professional market.

Therefore don't come with a manual in the box (expect you to know it all).

I would recommend the Premier for it's easy menu system, especially if you've fitted an Excel already.

They will use the same terminology (Guard, Guard Access etc etc)

[raveyard]

Bear in mind Premier Series panels are aimed for the professional market.

Therefore don't come with a manual in the box (expect you to know it all).

Errmmm... no install manual would indeed be a problem!

I assume that if you're buying a Premier box it should be possible to purchase an install manual as well somewhere, even if not a registered trade pro??

Whilst there was a steep learning-curve installing my first Veritas alarm + dialler, I was very happy with the Texecom install manuals, and found it a very nice system to program and use... the biggest compliment was that even the Mrs said she found it easy to use!! So I would like to stick with Texecom second time around if possible...