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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Technical Advice => Topic started by: Allen Higginson on May 24, 2006, 08:09:04 PM

Title: NHS Supported HMO -Query
Post by: Allen Higginson on May 24, 2006, 08:09:04 PM
Quick one - what exactly constitutes a C grade system???I know what the components are (as per 5839:Part 6) but what achieves it other than a Part 1 component system?
Title: NHS Supported HMO -Query
Post by: Graeme on May 24, 2006, 10:17:49 PM
The difference is that smoke alarms are linked to central control equipment not control and indicating equipment.

which i assume is something like a remote hush and test switch or similar
Title: NHS Supported HMO -Query
Post by: Allen Higginson on May 25, 2006, 07:17:53 AM
"Grade C: A system of fire detectors and alarm sounders (which may be combined in the form of
smoke alarms) connected to a common power supply, comprising the normal mains and a
standby supply, with central control equipment."
This sounds to me more like a PSU supplying the power to the heads, as opposed to a grade D system which has mains with internal battery back up.
However,I've just checked annex B which states -
"B.5.1 More effective control and monitoring of a fire detection and fire alarm system can be provided by
connecting all fire detectors to a common power supply, comprising the normal mains, rectified and
regulated as appropriate, with a standby supply, such as a secondary battery. Examples of such systems
include:
a) one or more smoke alarms and heat alarms operating at extra-low voltage and connected to a control
unit at an appropriate location in the dwelling;
b) intruder alarm systems or social alarm systems that incorporate control and indicating equipment to
which one or more fire detectors are connected; the detectors can be smoke alarms or fire detectors with
independent sounders.
B.5.2 This type of system normally incorporates a secondary battery of a type unsuitable for use in normal
domestic appliances and removable only with the use of a tool. The battery is, therefore, unlikely to be
removed for other purposes"
So, in reading this it's either a fire panel stuck in a meter cupboard somewhere (which explains a few things that I've came across) or an intruder panel (Arghhh!!!) with detection on it.
Title: NHS Supported HMO -Query
Post by: Allen Higginson on May 25, 2006, 02:51:54 PM
Must be my age - getting the picture now!! http://www.brk.co.uk/index.php?fuseaction=prod.flexi
Title: NHS Supported HMO -Query
Post by: Graeme on May 25, 2006, 06:20:10 PM
Flexipoint provides a Grade C system as defined by BS5839 Part 6. It comprises smoke detectors and alarm sounders connected to a common mains power supply, with battery back up in all units with an element of central control.


kinda similar to wot i said Buzz ;)
Title: NHS Supported HMO -Query
Post by: Allen Higginson on May 25, 2006, 06:48:28 PM
Ahhhh shaddapp!!
Title: NHS Supported HMO -Query
Post by: Graeme on May 25, 2006, 07:25:36 PM
like you say mate-it could be your age.

i'm still a young upstart and have it all to come one distant day... :D
Title: NHS Supported HMO -Query
Post by: Allen Higginson on May 26, 2006, 04:55:26 PM
In the words of Columbo "Just one more thing?" - For a grade C is it detection throughout or just in areas of circulation??
I must read up on things!!For reference - NHS occupied HMO + LD1 (Grade C)!!
Title: NHS Supported HMO -Query
Post by: Graeme on May 26, 2006, 05:44:04 PM
Buzz

LD1
Throughout with all circulation areas that form an escape route and in all areas where a fire might start other than shower rooms,toilets and bathrooms.
Title: NHS Supported HMO -Query
Post by: Allen Higginson on May 26, 2006, 08:46:58 PM
Quote from: Graeme Millar
Buzz

LD1
Throughout with all circulation areas that form an escape route and in all areas where a fire might start other than shower rooms,toilets and bathrooms.
I know that now!!!I just missed it first time I read through it!
Title: NHS Supported HMO -Query
Post by: Graeme on May 26, 2006, 10:11:25 PM
well you did ask mr Grumpy