IET
Decrease font size
Increase font size
Topic Title: Fire Rated Clip.
Topic Summary: Spacing.
Created On: 16 March 2019 09:57 am
Status: Read Only
Linear : Threading : Single : Branch
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 16 March 2019 09:57 am
User is offline View Users Profile Print this message



Wessex

Posts: 148
Joined: 26 June 2009

Looking for guidance on said clip in conjunction with PVC type.If exposed I would use all fire rated as would look odd mixing the two. In areas concealed, but there is still a requirement to provide fire rated support. How often is required on a single cable run ? Or rule of thumb maybe.
 16 March 2019 11:17 am
User is offline View Users Profile Print this message



AJJewsbury

Posts: 17795
Joined: 13 August 2003

I guess the fundamental requirement is to ensure that the conductors don't droop low enough to entangle anyone, should a fire occur. To that end I guess we need to keep in mind that once some of the insulation has melted or burned away the weight distribution may be different and there may be less friction from the remaining clips to restrain longitudinal movement too. So perhaps where cables are fixed across a ceiling at just above head height then there's not much margin, so perhaps every clip should be fire resisting; but where there's room for a sizeable safe droop and the cable ends are reasonably well anchored perhaps the suggestion I've heard elsewhere of one clip in three being fire resisting might be adequate (provided they can still support the full weight of the cable of course).
- Andy.
 16 March 2019 11:35 am
User is offline View Users Profile Print this message



Alcomax

Posts: 450
Joined: 12 November 2009

In areas concealed, but there is still a requirement to provide fire rated support.


Depends on concealed by what. If concealed by a building structure, boxing or partition or similar, Then that structure has to collapse before the cable does.

As for clipped direct above, across or to the side of where persons could be walking, you have to imagine what would happen "droop wise" to the cable, if the cable supports melted. There is no given spacing, only your judgement. Once you feel a particular position is more risky than usual, then probably no option but for full fire rated clipping, rather than a few positions to mitigate the "droop".
Statistics

New here?

  • To participate in discussions, please log in and introduce yourself.

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2021 FuseTalk Inc. All rights reserved.

 
..