Link to STU/monitoring equipment cable fault monitoring??

[g4vjc]

Can I have your thoughts please on this re-occurring problem.

A fire alarm system is to be linked to an intruder alarm system STU for monitoring. I know this gives a whole load of issues in terms of battery standby etc but putting those aside having overcome them as far as reasonably practicable my question is this:

The fire panel in question has fire & fault contacts but these are not monitored for cabling faults between the panel and the STU.

The fire contact can be overcome by using a spare sounder circuit to fire a relay at the STU and therefore monitor the cable by using the EOL resistor for the sounder circuit.

How can the fault contact cabling between the panel and the stu be monitored?......and I can't use an interface on the loop because these can't be programmed to mimic a fault on the fire panel.

Your help would be much appreciated.

[Galeon]

Your fault signal can be closed going open in any common fault , so your input into the signalling device needs to be a closed input on itself , so if any cabling becomes broken , for example it will bring up a fault. What you need to look are closed contacts into your receiving device , and not at the fire panel , therefore use a closed fire contact and you will have the same result. I personally don't like bell circuit triggers , if you silence this will remove the signal , ultimately they will see it as a restore ,(yes I know those large red things with blue lights will be there anyway)
Unless your system is very old addressable (not analogue) most generic panels can action a device off the loop in various guises, that's inputs and outputs.

[Graeme]

If you have fault relays on the intruder then you can monitor the state of the intruder psu via a spare zone on the fire panel.

[g4vjc]

Your fault signal can be closed going open in any common fault , so your input into the signalling device needs to be a closed input on itself , so if any cabling becomes broken , for example it will bring up a fault. What you need to look are closed contacts into your receiving device , and not at the fire panel , therefore use a closed fire contact and you will have the same result. I personally don't like bell circuit triggers , if you silence this will remove the signal , ultimately they will see it as a restore ,(yes I know those large red things with blue lights will be there anyway)
Unless your system is very old addressable (not analogue) most generic panels can action a device off the loop in various guises, that's inputs and outputs.

Yes I appreciate what you're saying in terms of a closed contact going open, this will provide monitoring if there is a break in the cable but won't monitor the cable for short circuit e.g the cable between the fire panel and the STU could be trapped and sat there closed but will never open in the event of a fire or fault. This doesn't meet the requirements of BS for monitoring of the cable as far as I'm aware.

The panel in question is fully analogue addressable from a very reputable manufacturer but unfortunately can't give a panel fault output from an interface and also doesn't have monitored fire or fault contacts.

[Wiz]

Clause 15 of BS5839 Part 1 2002 covers Communication with the fire service and has no recommendations that indicate that the connection between the cie and alarm transmission device need to be monitored for open and/or short circuit faults.

Clause 12 of BS5839 part 1 2002 covers Monitoring, integrity and reliability of circuits external to control equipment and makes no specific mention of the monitoring of the connection between the cie and alarm transmission device whilst it specifically mentions monitoring of detection and alarm warning device circuits.

Therefore, it may well be argued that you do not need to consider any monitoring of the connections being mentioned in this post.

[Thebeardedyorkshireman]

Was it Jim Reeves who sang welcome to my world?
The fire signal should not be derived from a silenceable output and should be monitored for open and short circuits. use a 4 core enhanced to the tx, one pair for fire and a closed circuit ( open in fault) for the fault signal.
You can also monitor the intruder panel fault contact if it has one via a separate cable, or o/c the EOL from the fire signal. List all the variations and confirm in writing that the client should obtain direct approval from his insurers.
Dave

[g4vjc]

Clause 15 of BS5839 Part 1 2002 covers Communication with the fire service and has no recommendations that indicate that the connection between the cie and alarm transmission device need to be monitored for open and/or short circuit faults.

Clause 12 of BS5839 part 1 2002 covers Monitoring, integrity and reliability of circuits external to control equipment and makes no specific mention of the monitoring of the connection between the cie and alarm transmission device whilst it specifically mentions monitoring of detection and alarm warning device circuits.

Therefore, it may well be argued that you do not need to consider any monitoring of the connections being mentioned in this post.

15.2 K ?

12.2.1a)9 ?

I think these just highlight the issue even more so that an Intruder STU is not suitable for fire monitoring, I wish panel manufacturers would just give a monitored fire and fault output as this would reduce the variations a fair bit.

[g4vjc]

Was it Jim Reeves who sang welcome to my world?
The fire signal should not be derived from a silenceable output and should be monitored for open and short circuits. use a 4 core enhanced to the tx, one pair for fire and a closed circuit ( open in fault) for the fault signal.
You can also monitor the intruder panel fault contact if it has one via a separate cable, or o/c the EOL from the fire signal. List all the variations and confirm in writing that the client should obtain direct approval from his insurers.
Dave

Yes so I loose one variation by providing monitoring of the fire signal cabling but gain one by using the silencable output...can't win!

What is the benefit of monitoring the intruder fault contact?

[Wiz]

Clause 15 of BS5839 Part 1 2002 covers Communication with the fire service and has no recommendations that indicate that the connection between the cie and alarm transmission device need to be monitored for open and/or short circuit faults.

Clause 12 of BS5839 part 1 2002 covers Monitoring, integrity and reliability of circuits external to control equipment and makes no specific mention of the monitoring of the connection between the cie and alarm transmission device whilst it specifically mentions monitoring of detection and alarm warning device circuits.

Therefore, it may well be argued that you do not need to consider any monitoring of the connections being mentioned in this post.

15.2 K ?

12.2.1a)9 ?

I think these just highlight the issue even more so that an Intruder STU is not suitable for fire monitoring, I wish panel manufacturers would just give a monitored fire and fault output as this would reduce the variations a fair bit.

You are spot-on g4vjc. I missed these. I apologise for my mistake.

After reading your last post of 09.21 today it occurred to me that I knew of dozens of installed transmission links where the signal was just normally open/normally closed and therefore started wondering if the BS even expected them to be fully monitored. I did a quick scan through the BS and unfortunately missed the clauses you have now highlighted. More haste, more cock-ups!

Whilst you quite rightly point out that panel manufacturers could produce monitored outputs I think it might be better if the STU that did any link monitoring and send a signal to the arc as necessary.

Therefore it now begs the question why STU manufacturers are providing equipment that could quite easily be built for open/short circuit monitored inputs, but don't! The BS requirement has been around since 2002 and surely someone would have considered this requirement by now. I believe that Gardiners and BT RedCare have recently worked together to produce a product called firestu.com and I have had a quick look at some info on this, but it seems that this still doesn't have the monitoring required, and the sort of thing that you are doing to provide the required monitoring is still necessary. Maybe you should talk with firestu.com on 0800 671 240 and ask them why.

[Thebeardedyorkshireman]

Intruder fault contact picks up the power supply which should then be sent to the arc as a FIRE fault, not just as an intruder fault (which will be sent as an alarm). Why do you insist on using a silenceable output???  If you really have no alternative, then you could use an sdu to do the monitoring but drive it hard in alarm from the spare fire contacts. There are other ways.
Some panels have Fire and fault monitored outputs, but only those that I was involved with the design of.
I even had a panel built with a monitored 12v output to feed the communicator but then they developed the 24V/12V subregulator and eventually the 24V Firestu.
The easy answer is to use a seperate signal.
We had a long post on this not very long ago
Dave

[David Rooney]

I thought EN54 compliant panels had to have a monitored fire output... maybe even a monitored fault output??

I know the Kentec Syncro panel has and I don't imagine they would have engineered it in for no reason....

But as stated previously.... you can still only feed a relay and the final connection to the STU is not fully monitored. Problem is the STU manufacturers probably see it as an engineering problem of the fire alarm panel and don't see why they should re-develop their equipment to provide the monitoring circuitry.

[Wiz]

Can I have your thoughts please on this re-occurring problem.

A fire alarm system is to be linked to an intruder alarm system STU for monitoring. I know this gives a whole load of issues in terms of battery standby etc but putting those aside having overcome them as far as reasonably practicable my question is this:

The fire panel in question has fire & fault contacts but these are not monitored for cabling faults between the panel and the STU.

The fire contact can be overcome by using a spare sounder circuit to fire a relay at the STU and therefore monitor the cable by using the EOL resistor for the sounder circuit.

How can the fault contact cabling between the panel and the stu be monitored?......and I can't use an interface on the loop because these can't be programmed to mimic a fault on the fire panel.

Your help would be much appreciated.

Hi g4vjc, after the 'rushed' info I previously gave you I felt guilty and that I had to come up with something better, so I have been giving this a bit of thought.

I have an idea, but I haven't had time to precisely check out exactly what is available. However, maybe you can look into it.

Your idea to use a relay at the end of a monitored sounder circuit to use for the 'fire' signal may be possible to extend for your use with the 'fault' signal.

C-tec manufatcure a part FF502P which is described as a 'Four zone monitored sounder extender, supplied on a double gang plate. provides four extra sounder circuits with open and closed circuit fault monitoring, two trigger inputs and one fault output'

I'm guessing that if you give the FF502P a 24V dc supply and connect your panel fault output relay to one of the inputs, and the your panel fire relay to the other input, then you will have two monitored circuits that will operate to 'fault' and the other two to 'fire'. The fault output of the FF502P could be interfaced in some way to generate a fault on the fire panel indicating open or short circuit on one of the links between the cie and the enclosure housing the transmission device as required by BS.

As I previously said, I haven't had time to check out this C-tec part - but it sounds like it could work. If not, maybe someone else supplies this type of monitoring pcb that would operate as I have described above.

[Graeme]

. Maybe you should talk with firestu.com on 0800 671 240 and ask them why?



Don't waste your time as i have used the FireStu several times and the first time i used it i wondered if the FireStu psu should be monitored by the CIE but it was not possible.

I phoned BT and this is an honest quote

"i have never heard of it (the FireStu)" and i got passed round technical and i could actually hear one guy say "don't give it (the call) to me, i don't know"

I then asked Gardiners tech who told me it is not a requirement to monitor the FireStu psu.

Fair enough that the 240v supply should be the same of the CIE then a power cut would trigger the CIE fault contacts anyway but what about if the FireStu psu batteries fail?

[Wiz]

Graeme, I haven't used the firestu.com but I have read some literature on it. This literature definitely gives the impression that there is quite sophisticated monitoring of it's psu, and that it has a fault warning output. I presumed that you would take this fault output into a fault input of the cie. Your experience seems to show things are not quite right with this product.

It also occurs to me that nowhere on the literature does it specifically state that it complies with BS5839, rather that it could be used in systems complying with BS5839 (I think these are two very different things)

My guess is that the actual communicator board is a Redcare unit and it has been built into a psu made by others, under the control/orders of Gardiners and BT RedCare don't want anything to do with the overall product since it only the communicator board that they really know anything about.

It amazes me that no-one seems to be manufacturing anything that can be used as a transmission device that can simply be connected easily to any standard fire alarm panel and provide everything needed to comply with BS5839

[Thebeardedyorkshireman]

Wiz
We manufactured in house an 'MFI' interface to go between the panel and the tx, up to the release of the 2002 BS. We looked at a redisign and basicaly the thing ends up as a two zone panel without the psu. The cost was high and on the basis that nobody else gives shared signalling a second thought, just throw some wires in, we abandoned it. Shame really but there you go!!
Dave