24V Smoke heads on 240V fire alarm system

[AnthonyB]

Visited a very old office building today with a rather torturous layout and an old fire alarm system that was an old CP1019 or earlier 240V system with just call points, cable and bells.

I noticed  that it had some smoke detection added on stair landings in two parts of the building in years gone by. Now first thought was 240V detectors, but the heads were not the oversize ones with the mesh head associated with mains ion detectors and were quite small and of a design I recognise from literature as common in the late 70's and 80's.

These heads & bases were not direct into the 240V circuit, but were all fitted onto boxes that were about 5' x 5' x 4' into which the cables ran.

I suspect that they are 24V heads & the box is some sort of relay/transformer, but wondering if anyone whose been around long enough to see the older stuff can confirm it (i'd post the picture if I knew how!)

It's mainly curiosity as the system will be put down for renewal, extension to the bit never covered and linked to the bit where a tenant ripped out the 240V stuff and put their own 2 zone conventional in.

I also uncovered the worst case of shine and sign with extinguishers going back over 25 years and am hoping the tenant will take it to Trading Standards.  The guy turned up every year with no tools and literally shined & signed for 25 years including last year - 2 of the extinguishers were 80's BCF's. He made his trip worthwhile each year by boosting his £14 service fee with various refills and refurbs that always brought the bill to around £85 despite the extinguishers all being exactly the same unchanged from 1971 (he even billled for refilling a Halon in 2004 a year after it would have been an offence to do so for a non prescribed use, good job he was faking).

Town & County Fire Protection Services from some suburban semi-detached in Goole is the offending contractor

[Wiz]

Visited a very old office building today with a rather torturous layout and an old fire alarm system that was an old CP1019 or earlier 240V system with just call points, cable and bells.

I noticed  that it had some smoke detection added on stair landings in two parts of the building in years gone by. Now first thought was 240V detectors, but the heads were not the oversize ones with the mesh head associated with mains ion detectors and were quite small and of a design I recognise from literature as common in the late 70's and 80's.

These heads & bases were not direct into the 240V circuit, but were all fitted onto boxes that were about 5' x 5' x 4' into which the cables ran.

I suspect that they are 24V heads & the box is some sort of relay/transformer, but wondering if anyone whose been around long enough to see the older stuff can confirm it (i'd post the picture if I knew how!)

It's mainly curiosity as the system will be put down for renewal, extension to the bit never covered and linked to the bit where a tenant ripped out the 240V stuff and put their own 2 zone conventional in.

I also uncovered the worst case of shine and sign with extinguishers going back over 25 years and am hoping the tenant will take it to Trading Standards.  The guy turned up every year with no tools and literally shined & signed for 25 years including last year - 2 of the extinguishers were 80's BCF's. He made his trip worthwhile each year by boosting his £14 service fee with various refills and refurbs that always brought the bill to around £85 despite the extinguishers all being exactly the same unchanged from 1971 (he even billled for refilling a Halon in 2004 a year after it would have been an offence to do so for a non prescribed use, good job he was faking).

Town & County Fire Protection Services from some suburban semi-detached in Goole is the offending contractor

It would not be technically impossible to step-down/rectify the 240V to provide 24V dc to modern detectors and provide relay(s) to provide signalling to the 240V bells. The large connection boxes seem to indicate that the components are installed within. The set-up would need some sort of reset facility because most non-addressable detectors 'latch' upon operation.

Whilst ignoring the overall age and standard the system is installed to, if the detectors operate to smoke, then I suppose this set-up might be considered a cheap solution for adding automatic detection to a 240V system.

However, as Chris Houston always reminds us in this forum, there are current regulations that do not allow fire alarm warning systems without a battery back-up facility.

[AnthonyB]

I know that the 240V set up is past it, but just wondered about the heads - obviously used as a cheap solution in the past to meet FP Act requirements.

Thanks

[AnthonyB]

Oh and there is no reset facility visible on the boxes.

The system itself is the most basic - one set of sounders and call points, no zoning and no panel - not even a silence/accept button to stop the bells whilst you replace a glass. The only control is the power supply switch.

[Wiz]

I know that the 240V set up is past it, but just wondered about the heads - obviously used as a cheap solution in the past to meet FP Act requirements.

Thanks

They could have used the most modern and technically excellent heads with the appropriate interface to the old 240V system. At the end of the day it isn't a very satisfactory solution, but the user probably wouldn't pay for anything better!

[Wiz]

Oh and there is no reset facility visible on the boxes.

The system itself is the most basic - one set of sounders and call points, no zoning and no panel - not even a silence/accept button to stop the bells whilst you replace a glass. The only control is the power supply switch.

I presume they use the power supply switch to reset a 'latched' detector.

[Graeme]

it never ceases to amaze me why companies bother to go all the hassle of  to inventing weird ways of tyring to get new to work with old.

old that should have been ripped out years ago. More hassle than it's worth and you still end up with a crap system at the end of it.

[Benzerari]

Visited a very old office building today with a rather torturous layout and an old fire alarm system that was an old CP1019 or earlier 240V system with just call points, cable and bells.

I noticed  that it had some smoke detection added on stair landings in two parts of the building in years gone by. Now first thought was 240V detectors, but the heads were not the oversize ones with the mesh head associated with mains ion detectors and were quite small and of a design I recognise from literature as common in the late 70's and 80's.

These heads & bases were not direct into the 240V circuit, but were all fitted onto boxes that were about 5' x 5' x 4' into which the cables ran.

I suspect that they are 24V heads & the box is some sort of relay/transformer, but wondering if anyone whose been around long enough to see the older stuff can confirm it (i'd post the picture if I knew how!)

It's mainly curiosity as the system will be put down for renewal, extension to the bit never covered and linked to the bit where a tenant ripped out the 240V stuff and put their own 2 zone conventional in.

I also uncovered the worst case of shine and sign with extinguishers going back over 25 years and am hoping the tenant will take it to Trading Standards.  The guy turned up every year with no tools and literally shined & signed for 25 years including last year - 2 of the extinguishers were 80's BCF's. He made his trip worthwhile each year by boosting his £14 service fee with various refills and refurbs that always brought the bill to around £85 despite the extinguishers all being exactly the same unchanged from 1971 (he even billled for refilling a Halon in 2004 a year after it would have been an offence to do so for a non prescribed use, good job he was faking).

Town & County Fire Protection Services from some suburban semi-detached in Goole is the offending contractor

I had seen one day in one of the wards of NHS outside London, with old stuff smoke detectors of 240V, they had not been decommissioned, even it had been replaced by old HAES panel, we had been in a position to decommission both HAES stuff and the 240V system. this later had smoke detectors the size of radio smoke sounder of EMS but far less smart than that, but it seemed they operated for fire alarms on an open circuit basis...

If I had been told to upgrade such systems, I would call the office asking for couple of days off sick rather than dealling with it.

[Wiz]

it never ceases to amaze me why companies bother to go all the hassle of  to inventing weird ways of tyring to get new to work with old.

old that should have been ripped out years ago. More hassle than it's worth and you still end up with a crap system at the end of it.

Spot on Graeme.

The problem normally starts when, as part of his electrical works, an electrical contractor is asked to add a couple of detectors and a call point to the 'existing' fire alarm system

He assumes that because he has been asked to do so, then the system can accommodate detectors and so prices on that level of work.

During the job he realises that the existing system is an unmonitored 240V 3-wire system only ( or some other non-current standard system). No one will pay to have it upgraded. He hasn't priced to upgrade the whole system, just to add a few devices. He is told his quote includes for installing the additional equipment, so it's his problem to come up with a solution!

If jobs went the way they should do, then you would have a system designer, who should discover the existing problems and come up with a solution that the installer prices to. This rarely happens and all installers should be aware of this potential problem in 'refurb' or 'modification' jobs and 'cover' themselves in their quotation for the work by stating exactly what they have allowed for.

[AnthonyB]

Just found a way to share images:



This is one of the detectors I referred to.

[kurnal]

Those alarm cable routings through the doors look a little heath robinson too!

[Wiz]

Just found a way to share images:

http://i255.photobucket.com/albums/hh130/contactacb/FireNet/24VDCDSon240VACsystem.jpg

This is one of the detectors I referred to.

It looks like an Apollo Series 30 Optical, which makes it about 12 years old.

The box below the detector certainly looks big enough to house a 240V to 24V transformer/rectifier.

[Wiz]

Those alarm cable routings through the doors look a little heath robinson too!

Well noticed Prof. K - I reckon the one on the left goes throught the door opening and the door can't be closed shut anymore!

I wonder what type of cable is being used? The nail-in cable clips makes me think it must be pvc/pvc flex.

It seems that everything on this job is sooooo far away from current recommendations.

[AnthonyB]

Yes, I agree with all the above.

Compartmentalisation is none existent with not a single fire door - some parts of the site wing it just on travel distance, but the main office part (basement boiler room, ground to second floor, two stairs, offices and a link corridor off) has no fire doors, no closers, no FR glazing and wooden plank partitions.

And yet it used to hold a fire certificate!

[Allen Higginson]

Just found a way to share images:

http://i255.photobucket.com/albums/hh130/contactacb/FireNet/24VDCDSon240VACsystem.jpg

This is one of the detectors I referred to.

It looks like an Apollo Series 30 Optical, which makes it about 12 years old.

The box below the detector certainly looks big enough to house a 240V to 24V transformer/rectifier.

It's an ion if I'm not mistaken - either way it's an "interesting" set up right enough!!!