Author Topic: Mains electrics  (Read 5297 times)

Offline lingmoor

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Mains electrics
« on: March 27, 2008, 09:29:13 AM »
Hi

I've recently carried out a FRA at a health care premises and found that one of the wards housed the mains electric cupboard for the whole building and were in a fire resisting cupboard. The FRA guide states that mains electrical gear should not be in the same compartment, however this has always been the case and have been accepted by the fire authority. Have I read this guide correctly?

I would be grateful for your views

Non-patient access areas

Fires may start in a non-patient access area and
affect patients in an adjoining area. The following
non-patient access areas should not be in the
same compartment as patient access areas:

• boiler house;
• central sterile supply;
• central staff changing;
• commercial enterprises;
• flammable stores;
• hospital sterilising and disinfection unit;
• laundries;
• main electrical gear;
• main kitchens;
• main stores;
• medical gas store;
• medical records;
• pathology;
• patient services;
• pharmaceutical (manufacturing);
• refuse collection/disposal areas, incineration;
• staff on-call rooms; or

Offline Mr. P

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Mains electrics
« Reply #1 on: March 27, 2008, 10:40:33 AM »
To what standard is the fire resisting cupboard, and, is it covered by detection from with-in?

Midland Retty

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Mains electrics
« Reply #2 on: March 27, 2008, 10:45:56 AM »
So long as the electrics cupboard was constructed from fire resisting materials offering a minimum standard of atleast thirty minutes fire resistance then there shouldn't be too much of an issue.

But do bare in mind what Mr P said about fire detection.

The main problem with FR stores and cupboards is that fire could start within them and in theory burn happily inside for thirty minutes.

Consequently the only time people get to find out the fire is when flame or smoke breaches the FR construction after 30 minutes.

So you may need to consider AFD, or you may feel the fire would burn itself out and would never breach the FR construction.

Its a judgement call at the end of the day based on the fuel / loading inside the cupboard.

Offline lingmoor

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Mains electrics
« Reply #3 on: March 27, 2008, 11:03:39 AM »
Mr P

It is 30 minutes fire resisting and it has auto detection...my first reaction was that this would be ok and was saying so in my report, then noticed the bit in the guide

Midland Retty

Yes thats one of those dilemmas,  say in offices with 30 minutes fire doors that don't have smoke detection installed but have detection in the corridor outside. If the room is unoccupied and a fire started in there, then the occupants of other rooms off the corridor wouldn't know til either it burns itself out through lack of oxygen or it penetrated the door and smoke sets off the corridor alarm. Someone once asked me in those cases wouldn't it be better to have no smoke seals on the door to enable a small amount of smoke to hit the detector.

Similar questions have been asked about shutting doors in homes at night when the detector is at the base of the stairs.


Thanks for the replies

Midland Retty

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Mains electrics
« Reply #4 on: March 27, 2008, 12:56:51 PM »
Quote from: lingmoor
Mr P

It is 30 minutes fire resisting and it has auto detection...my first reaction was that this would be ok and was saying so in my report, then noticed the bit in the guide

Midland Retty

Yes thats one of those dilemmas,  say in offices with 30 minutes fire doors that don't have smoke detection installed but have detection in the corridor outside. If the room is unoccupied and a fire started in there, then the occupants of other rooms off the corridor wouldn't know til either it burns itself out through lack of oxygen or it penetrated the door and smoke sets off the corridor alarm. Someone once asked me in those cases wouldn't it be better to have no smoke seals on the door to enable a small amount of smoke to hit the detector.

Similar questions have been asked about shutting doors in homes at night when the detector is at the base of the stairs.


Thanks for the replies
Yes youre absolutely right in the poitns you made - it's a toughie.

I advocate no strips on fire doors accessing rooms without AFD

Offline kurnal

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« Reply #5 on: March 28, 2008, 07:10:02 AM »
Now then Midland Retty behave yourself!!

If a room needs AFD then that is what it should have. Just because it is bad in one respect we cant go making it worse to compensate.

A well fitting fire door with seals will keep the escape route tenable for say 20 minutes. A fire door without seals will probably make that escape toute untenable within 10 minutes. Yes without seals the smoke detecotr in the corridor will operate earlier- but only becaiuse our escape routes will become untenable much more quickly so it is much more likely that people will be trapped in the building.  

Same goes for the domestic dwelling leaving the downstairs doors open.  If the doors are open the smoke alarm will probably operate at 2 minutes after ignition but the escape route will fill with fire and smoke in 2-4 minutes. If the doors are closed then the smoke alarm will probably not operate for 4 minutes but the the escape routes should remain useable for 10 minutes.  Thats 10 minutes to escape rather than 2 minutes. Which is better?

Offline lingmoor

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Mains electrics
« Reply #6 on: March 28, 2008, 09:00:17 AM »
Quote from: kurnal
Now then Midland Retty behave yourself!!

If a room needs AFD then that is what it should have. Just because it is bad in one respect we cant go making it worse to compensate.

A well fitting fire door with seals will keep the escape route tenable for say 20 minutes. A fire door without seals will probably make that escape toute untenable within 10 minutes. Yes without seals the smoke detecotr in the corridor will operate earlier- but only becaiuse our escape routes will become untenable much more quickly so it is much more likely that people will be trapped in the building.  

Same goes for the domestic dwelling leaving the downstairs doors open.  If the doors are open the smoke alarm will probably operate at 2 minutes after ignition but the escape route will fill with fire and smoke in 2-4 minutes. If the doors are closed then the smoke alarm will probably not operate for 4 minutes but the the escape routes should remain useable for 10 minutes.  Thats 10 minutes to escape rather than 2 minutes. Which is better?
Kurnal

I'm not disputing your timings because to quote them you must have some research notes. Looking at it though, the home door is probably not a fire door and probably doesn't have seals.... are you saying that its ok for this scenario when occupants will be asleep upstairs and not for the office scenario when occupants will be awake and just off the corridor as mentioned in my example above?

by the way I'm not saying you're wrong...just trying to get where your coming from mate

Offline Tom Sutton

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« Reply #7 on: March 28, 2008, 10:05:27 AM »
In the seventies we adopted the theory about smoke percolating through the doors of hotel bedrooms and actuating the smoke detectors in escape routes it was rubbished by the FRS.

Let the master explain see submission 4 http://www.fire.org.uk/punbb/upload/viewtopic.php?id=786

No disrespect to the present contributors.
All my responses only apply to England and Wales and they are an overview of the subject, hopefully it will point you in the right direction and always treat with caution.

Offline lingmoor

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Mains electrics
« Reply #8 on: March 28, 2008, 12:26:06 PM »
Thanks for that twsutton

very interesting...

so what he is saying is that research shows that the products of combustion from the top of the door gives off thick non bouyant smoke before any other smoke from the room enters the corridor....and because of that,  smoke may not set off the alarm in large corridors (unless they are right outside the room of origin) and by the time the alarm activates the corridor is smoke logged

On that evidence then it's either seals or alarms in rooms (or both)

My corridor was only small though ;)

ps can someone tell 'the master' to put one or two spaces in his writing...me eyes are hurting! ;)

Midland Retty

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Mains electrics
« Reply #9 on: March 28, 2008, 01:10:58 PM »
Quote from: kurnal
Now then Midland Retty behave yourself!!

If a room needs AFD then that is what it should have. Just because it is bad in one respect we cant go making it worse to compensate.

A well fitting fire door with seals will keep the escape route tenable for say 20 minutes. A fire door without seals will probably make that escape toute untenable within 10 minutes. Yes without seals the smoke detecotr in the corridor will operate earlier- but only becaiuse our escape routes will become untenable much more quickly so it is much more likely that people will be trapped in the building.  

Same goes for the domestic dwelling leaving the downstairs doors open.  If the doors are open the smoke alarm will probably operate at 2 minutes after ignition but the escape route will fill with fire and smoke in 2-4 minutes. If the doors are closed then the smoke alarm will probably not operate for 4 minutes but the the escape routes should remain useable for 10 minutes.  Thats 10 minutes to escape rather than 2 minutes. Which is better?
I always behave... mores the pitty!

Totally agree with your comments there.

Trouble is that we do come across alot of small electrical cupboards and you wonder whether they should or shouldn't have smoke detection within them, do you let a fire break out of the FR enclosure undetected?

If only you could clone "Clevelandfire" you could have one of him in each room with a small fan, and in the event of fire he could act as a human sprinkler.

It reduces the requirement for AFD, fire doors, smoke seals etc and the only ongoing maintenance would be plying him with Newcastle Brown Ale

Sorry being silly.

Offline Tom Sutton

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« Reply #10 on: March 28, 2008, 07:31:42 PM »
Quote from: lingmoor
ps can someone tell 'the master' to put one or two spaces in his writing...me eyes are hurting! ;)
Sorry you could never tell Colin anything ask PhilB :)
All my responses only apply to England and Wales and they are an overview of the subject, hopefully it will point you in the right direction and always treat with caution.

Offline Big A

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Mains electrics
« Reply #11 on: April 01, 2008, 10:45:38 AM »
Quote from: kurnal
Now then Midland Retty behave yourself!!


Same goes for the domestic dwelling leaving the downstairs doors open.  If the doors are open the smoke alarm will probably operate at 2 minutes after ignition but the escape route will fill with fire and smoke in 2-4 minutes. If the doors are closed then the smoke alarm will probably not operate for 4 minutes but the the escape routes should remain useable for 10 minutes.  Thats 10 minutes to escape rather than 2 minutes. Which is better?
Sorry to be picky but surely that's only six minutes escape time if you're still asleep for the first four of the ten minutes. Still better than the first scenario, though.

Isn't escape time the new travel distance?