Fire Alarm Circuit RCD Protection TT System

[Strima]

And to bring my side of this thread to a close.

The landlord has had another FRA done and the system has been put down as LD2 D1 so he's going for a wireless system...

 

[Steviec1]

And to bring my side of this thread to a close.

The landlord has had another FRA done and the system has been put down as LD2 D1 so he's going for a wireless system...

It will still need a supply!

 

[loz2754]

Yes it will still need a supply, but a Grade D1 system can be wired to local lighting circuits and radio interlinked. And as they are self contained they will not need wiring in FP.

 

[Strima]

It will still need a supply!

Fed from a local lighting circuit which is acceptable.

I'm only getting involved with wiring the bases etc, another company is being paid to design and commission the system.

 

[Darkwood]

Ah, OK.

I had assumed it was like Flexishield and the foil shield would take out the RCD/OCPD if penetrated by a nail, etc.

Thanks for this info westwood10. I did not realise that FP200 is not suitable for this application. Following on from your post, I did a little research. I think it has to do with the construction of the foil shield, in that it is not capable of carrying a large fault current for long enough to operate the OCPD. Every day's a school day...

In many systems if FP200 is employed it uses the foil as a shield from interference and if it is a monitored addressable system in use then the foil and 'earth' core is effectively isolated from common supply earth and is separately monitored by the panel, you can easily identify where this is in place as the panel usually has separate terminal inputs for the 'earth' core and any device will be clear on connecting up the devices that the 'earth' core is not fitted to any common installation earth.

@pc1966
I assume you are simply talking domestic 230v mains linked systems here which seldom use FP200, almost all systems using FP200 are monitored and the voltage down these cables is <30v DC, shorting the cable out will either pop a F/A panel glass fuse and/or the panel will actually isolate that particular zone and flag a fault warning.