Smoke Detector Wiring

[Wilko]

Fresh back from a few days away, I'm tempted to ask "so would normal cable be flame propagating ? "
Fire rated cables I get, but is that the same as non flame propagating ?
May need to duck off back to Heidi Land

 

[westward10]

Think people are so blinded by Am 3 and fire resistant fixings they ignore the requirements for cable systems on escape routes and T&E most certainly would not comply even if it were fixed with indestructible clips. Comment frequently when doing FRAs on this type of thing.

 

[bilbo_88]

Ok great, thanks for all your advice guys. And for those who were asking it was a grade D system

 

[Ian1981]

Try non fire propagating pvc conduit to bs en 61386-1
Bs en 50085
Bs 4607
All expectable in escape routes.

Winner rating??
Are we still in school??

 

[Wilko]

Reading that 422.2.1, towards the end it does say for BD2/3/4 the wiring systems shall be fire rated... (edit : just read Ian post #24 )
I did set fire to a cable to see what happened - not as bad as I'd hoped thought with the cable self extinguishing within about 10sec. Not surprising it failed IR testing after meeting Mr Rothenberger. Now for the pics

 

[Ian1981]

Reading that 422.2.1, towards the end it does say for BD2/3/4 the cables shall be fire rated...
I did set fire to a cable to see what happened - not as bad as I'd hoped thought with the cable self extinguishing within about 10sec. Not surprising it failed IR testing after meeting Mr Rothenberger. Now for the pics

View attachment 36346

Try that with LSOH cable which is non fire propagating and will not give off the fumes standard twin & earth will

 

[westward10]

Ok great, thanks for all your advice guys. And for those who were asking it was a grade D system

So what did the EICR say.

 

[bilbo_88]

So what did the EICR say.

FP200 not used for smoke detectors- C2

Had no regulation reference or anything

 

[Ian1981]

FP200 not used for smoke detectors- C2

Had no regulation reference or anything

Potentially dangerous???

 

[Octopus]

Potentially dangerous???

No - C3 maybe?

 

[Ian1981]

No - C3 maybe?

I would say it's more to do with a fire alarm service report issue and not a eicr.
You could note it on the eicr in comments if there was an issue but bs 7671 don't cover fire alarms.
Bs 5839 -1
Bs 5839-6 for dwellings

 

[westward10]

FP200 not used for smoke detectors- C2

Had no regulation reference or anything

I would contact them and ask their reasons. A Grade D system does not need fire resisting cable unless the requirements of BS7671 could only be met by doing so. I find it unlikely, though not impossible the reason is for an inappropriate wiring system on an escape route. More likely they have misread BS5839-6 or confused it with BS5839-1, the fact they have given a Code 2 is neither here nor there and it would be interesting to know why they have picked up on it to resolve your problem.

 

[davesparks]

Reading that 422.2.1, towards the end it does say for BD2/3/4 the wiring systems shall be fire rated... (edit : just read Ian post #24 )
I did set fire to a cable to see what happened - not as bad as I'd hoped thought with the cable self extinguishing within about 10sec. Not surprising it failed IR testing after meeting Mr Rothenberger. Now for the pics

View attachment 36346

fire will tend to travel upwards rather than down so you have it biased towards self extinguishing there. If you did it again but set fire to the bottom of a vertical section of cable you might get it to burn a bit longer.

 

[charlie76]

An interesting read if you have 10 minutes spare.

 

[tazz]

We are going off in a tangent here..lol
Domestic fire detection must meet BS5839 part 6 & BS 7671. Grade D can be wired from the consumer unit or from a local light fitting, in normal T&E. If specified then LSOH. As with emergency lighting, the units contain back up batteries. So the cable is sacrificial. The units also require a screwdriver to remove from the base, giving total isolation from mains, complying with the lockable isolation rule. Grading such as A,B,or C utilize a central psu, or control panel so the cable now becomes and issue to supply as long as possible. So here FP or Pyro would be required.