Spot The Problem

Talk Electrician Forum

Help Support Talk Electrician Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

M107

Billy-the-Kid
Joined
Feb 18, 2008
Messages
5,561
Reaction score
28
Location
Berkshire
2.5mm Supply to FA switch fuse fed in 2.5mm from main switch? 63A TP MCB not adequate O/L protection, but then again you could argue the fact that the 2.5mm could never be overloaded due to the 6A MCB upstream. FA switch fuse not fed in Fire-tuff/Pyro cable?

Am I missing something here?

GS

 
Interesting one this. Although i dont like it the fire alarm feed cable size is acceptable due to the short run and CPD. Then the lack of a fire proof cable, is that needed in this instance, i am not sure. I suppose the question here is not the TW & e link but the SWA feeding the board is not fire rated. Should the fire alarm even be connected there ?

The big question, why is the fire alarm supply turned off.

 
I agree. There's a specific reg somewhere that allows a smaller cable than normal for the OCPD providing there's downstream OCP and it's a "short run" and protected from physical damage.

I would argue fire alarms have batteries so they carry on working if the power goes, so the fire rating of the supply cable is less important than the other cables associated with it.

And the fire alarm is turned off as the cover is off and someone is working on it.

 
Right, I must be on the right path! After a few shandy's I thaught I had missed something else blatantly obvious!

GS

 
Andy wins..................like I said all I've done is take the piccy (and isolate)

 
I agree. There's a specific reg somewhere that allows a smaller cable than normal for the OCPD providing there's downstream OCP and it's a "short run" and protected from physical damage.

I would argue fire alarms have batteries so they carry on working if the power goes, so the fire rating of the supply cable is less important than the other cables associated with it.

BS5839 states the mains supply has to be made with a fire rated cable

And the fire alarm is turned off as the cover is off and someone is working on it.

No its not.
 
No you win a pair of welly boots ................................................for your next trip to Wales

 
missing cover?
Andy wins..................like I said all I've done is take the piccy (and isolate)
Are you referring to the missing busbar cover?

Or was the entire front cover missing as well, and when you walked into the room, that was what you saw?

A kind of trick question as I assumed you had removed the front cover yourself to take the picture.

 
Besides what has been said before...... The fire alarm MCB is off and it clearly states not to turn it off LOL

 
Dave what you see in the photo is exactly what I found when I opened the cupboard door, all I did was isolate the main switch & took the picture.

Spoke to the site guy today & he didn't know who or when the last person did any work on the electrics in the old workshop/store (used to be class rooms), but a bit of rummaging amongst all the carp in storage & we found the front covers for the DB & Alarm panel................no sign of the busbar cover though.

 
At least you found the main cover for the board, that's a start.

Perhaps you can buy a replacement busbar cover, or fabricate your own. It would be a real shame to have to change the board for the want of a busbar cover.

 
No you win a pair of welly boots ................................................for your next trip to Wales
Thats for you when you meet a girl believe her name will be BaaaaaaaBaaaaaaaRaaaaaaa

 
Top