IET logo
 
IET
Decrease font size
Increase font size
Topic Title: Secondary Supplies to Firefighting Shaft
Topic Summary:
Created On: 17 May 2011 10:12 AM
Status: Post and Reply
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.
 17 May 2011 10:12 AM
User is offline View Users Profile Print this message



clarky280

Posts: 78
Joined: 10 June 2008

Hi
A building is being refurbished with full strip-out of electrical services and refurb. The fire strategy does not involve a firefightling lift or sprinklers but there will be a firefighting shaft with dry risers. BS9999 and BS8519 talks of having secondary supplies to firefighting shaft power and lighting. Can this be provided with batteries for this particular case (i.e. self-contained emergency fittings etc) or is a secondary supply required?

Thanks.
 17 May 2011 10:50 AM
User is offline View Users Profile Print this message


Avatar for OMS.
OMS

Posts: 19430
Joined: 23 March 2004

Originally posted by: clarky280

Hi

A building is being refurbished with full strip-out of electrical services and refurb. The fire strategy does not involve a firefightling lift or sprinklers but there will be a firefighting shaft with dry risers. BS9999 and BS8519 talks of having secondary supplies to firefighting shaft power and lighting. Can this be provided with batteries for this particular case (i.e. self-contained emergency fittings etc) or is a secondary supply required?



Thanks.


In the absense of more information, I would start from the point that the fire fighting shaft (without a lift) needs to support (as a minimum):

. normal lighting and other services within the fire-fighting shaft;
. the fire and rescue service communications system
. any powered ventilation or pressurization system which operates in conjunction with the operational use of the fire-fighting shaft;
. any pump(s) required to feed the fire main

These should be available for 3 hours minimum

Can you use batteries, yes - but it may be a big battery set to support any significant load.

Providing emergency, rather than normal lighting levels isn't usually aceptable.

If you just have lighting, there are plenty of micro invertor "UPS" type packages on the market where essentially you run a 230V output direct to emergency and normal luminaires and that keeps the supply up for say 3 hours when the mains fails - failure of cabling or after the 3 hour duration then brings on the emergency lighting as usual (in theory at least - but that far into an incident it's either calmed down or turned into a real drama)

Regards

OMS

-------------------------
Failure is always an option
 17 May 2011 02:56 PM
User is offline View Users Profile Print this message



MickeyB

Posts: 181
Joined: 18 January 2003

Originally posted by: clarky280

Hi

A building is being refurbished with full strip-out of electrical services and refurb. The fire strategy does not involve a firefightling lift or sprinklers but there will be a firefighting shaft with dry risers. BS9999 and BS8519 talks of having secondary supplies to firefighting shaft power and lighting. Can this be provided with batteries for this particular case (i.e. self-contained emergency fittings etc) or is a secondary supply required?



Thanks.


As stated above by OMS a secure and fire resistant secondary electrical supply is required for specific equipment required to keep the fire fighting shaft (lobby) smoke free.

If the fire fighting lobby contains a dry riser only the lobby would typically be 2hr fire rated with manually opening windows to atmosphere at each floor level (for vent).

You could have AOV's (automatic opening vents) connected to a dedicated vent control panel (with smoke detection and manually release breakglass units) and interfaced with the fire alarm system. The AOV's allow for extended travel distances between fire doors/ zones.

The stair may have an AOV at the top for smoke control it would depend on how the lobby interfaces with the stair.

Overall, for the above equipment and lighting etc... standby alone battery packs in luminaires or a smaller central 'stair' type system is all that is required. Cables for 'emergency' use (fire alarm, emergency lighting, disabled intercom, fire telephone), if exposed, would be 120min rated (assume no sprinklers). If enclosed in luminaires the 230V supply cable could be regular SWA.
 02 October 2013 12:51 PM
User is offline View Users Profile Print this message



pjmacdonald

Posts: 15
Joined: 27 February 2002

Some intersting guidance here, thanks. One minor comment, though. Regarding your last paragrapth: "Overall, for the above equipment and lighting etc... standby alone battery packs in luminaires...". I assume you don't mean integral battery packs supporting the escape lighting? I was under the impression BS9999 requires the 'normal' lighting to be supported for the required duration.

-------------------------
pjmacdonald
 08 October 2013 05:01 PM
User is offline View Users Profile Print this message



MickeyB

Posts: 181
Joined: 18 January 2003

Normal lighting will be supported for the required duration by say a 3hr integral battery......
If the SWA cable supplying the luminaire fails then the circuit is broken and the luminaire illuminates.
Fire rated cabling is required for communication or power that needs to operate in the event of fire for the rated duration.
The 2nd power source for the luminaire could be the integral battery..... for the lift this would be remote and therefore fire rated.
Statistics

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2014 FuseTalk Inc. All rights reserved.