High integrity circuit for network/CCTV equipment

[Seb101]

Hi all,

I want to put my network and CCTV gear on a non-RCD circuit along with the Alarm system.

I currently have an alarm system fitted, which is on its own 16A non-RCD circuit, with the control panel in the under-stairs cupboard. I want to locate the network switch and CCTV recorder in the same location on the same circuit.

The alarm control box is fed directly from the consumer unit, with a 13A fused isolation switch on the wall just before it. Would it be acceptable to directly wire in a 4-gang power strip from the load side of this isolation switch?

Cheers.

 

[OwainDIYer]

electrically yes, but possibly not compliant with the BS for intruder alarm systems to have the alarm supply shared with something else.

 

[Seb101]

I think this is going to be one of those big grey areas - what counts as an alarm system and what doesn't? Technically my CCTV is an alarm system as it detects movement on the cameras and sends me alerts to my mobile phone. For that complete 'alarm' system to work, it needs the CCTV recorder, the network switch and the DSL modem to be active. So wiring those into the alarm spur would, in my mind, still make it an alarm spur.

17th edition regs allow non-RCD protected sockets if they are labelled for a specific purpose, and this is just a spur off an existing circuit so is non-notifiable. All in all, I think I'm good to go.

The only question is around the fuse - it's 3amp not 13amp as I previously said which might be pushing the limits with the alarm and network equipment going through it. However the circuit is on a 16A breaker and is run with 2.5mm T+E, so I don't see any reason I couldn't swap this out for a 5amp or even 13amp fuse.

 

[Seb101]

Actually, I've changed my mind. I'm going to leave the 3A fused protecting the original alarm and get a 13A fused power strip and wire it to the supply-side of the isolator.

 

[JohnW2]

17th edition regs allow non-RCD protected sockets if they are labelled for a specific purpose ...

That is true, but the regs still require RCD protection for any new (ordinary) cable buried less than 50mm deep in walls. Hence, if there were any such new wiring but no RCD protection, it would have to use something like armoured cable, or be enclosed in steel conduit.

Kind Regards, John

 

[JohnW2]

I think this is going to be one of those big grey areas - what counts as an alarm system and what doesn't?

You said 'along with the alarm system' - which seemed to imply that there is an actual 'alarm system' as well as the CCTV.

Kind Regards, John

 

[Seb101]

You said 'along with the alarm system' - which seemed to imply that there is an actual 'alarm system' as well as the CCTV.

Kind Regards, John

Correct - there is a traditional doors/windows/PIR alarm system that was installed in the house when it was built. It's faulty and I don't use it. My CCTV system is what I actually use for home security.

 

[Seb101]

17th edition regs allow non-RCD protected sockets if they are labelled for a specific purpose ...

That is true, but the regs still require RCD protection for any new (ordinary) cable buried less than 50mm deep in walls. Hence, if there were any such new wiring but no RCD protection, it would have to use something like armoured cable, or be enclosed in steel conduit.

Kind Regards, John

Right - but if I come straight out of the fused unit and tack the flex to the surface of the wall, which is what I planned to do anyway, then it doesn't count as buried cable so the RCD is still not required?

 

[JohnW2]

Right - but if I come straight out of the fused unit and tack the flex to the surface of the wall, which is what I planned to do anyway, then it doesn't count as buried cable so the RCD is still not required?

That is correct.

In passing, I have to say that I personally don't find the argument for having the alarm+CCTV on a non-RCD circuit to be very compelling. To have the alarm/CCTV detecting anything important at the very same time that an RCD had tripped (itself a very rare occurrence) must surely be 'vanishingly improbable'? Another option, of course, would be to have just the alarm+CCTV supplied by an RCBO - so that trips due to anything other than the alarm+CCTV itself (in which case they probably wouldn't be functioning, anyway) would not be a problem.

Kind Regards, John

 

[Seb101]

Right - but if I come straight out of the fused unit and tack the flex to the surface of the wall, which is what I planned to do anyway, then it doesn't count as buried cable so the RCD is still not required?

That is correct.

In passing, I have to say that I personally don't find the argument for having the alarm+CCTV on a non-RCD circuit to be very compelling. To have the alarm/CCTV detecting anything important at the very same time that an RCD had tripped (itself a very rare occurrence) must surely be 'vanishingly improbable'? Another option, of course, would be to have just the alarm+CCTV supplied by an RCBO - so that trips due to anything other than the alarm+CCTV itself (in which case they probably wouldn't be functioning, anyway) would not be a problem.

Kind Regards, John

John - I completely agree - and in reality this is for convenience rather than best practice - the alarm circuit is installed in the ideal location for the CCTV unit to be located, and there are no ring main outlets anywhere near by to take a spur from - it's the difference between a 30 minute job and an all day job. The only reason I'm not putting an RCBO on this is because it was wired pre-RCD requirements and I can, within regulations, get away with not doing putting one in. I'm happy, given that the socket is out of the way, at ceiling height and being wired for one specific purpose to supply low-power electronics with double insulated transformers that it does not need an RCD for safety reasons.

 

[SimonH2]

Actually, I've changed my mind. I'm going to leave the 3A fused protecting the original alarm and get a 13A fused power strip and wire it to the supply-side of the isolator.

My preference would be to add an additional connection unit or socket.

 

[RF Lighting]

I've got a normal socket which supplies a UPS to power my CCTV.

 

[bernardgreen]

I've got a normal socket which supplies a UPS to power my CCTV

Very sensible. Especially for those people whose "alarm" system is totally dependant on motion detection in the CCTV images. For these people loss of power means no effective alarm system.