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gadfly56

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Well it finally happened. During the recent weather frenzy here in New Jersey, one of our customers lost power. Some time ago they converted their phones to VoIP. With no battery backup. Annnnnd...they had a fire. Couldn't understand why the fire department didn't show up :slaphead:. It's not clear how this is particular case is going to play out, but we know that more and more customers are going to be moving away from POTS. It's clear in fact that in may locations POTS may simply not be available under any circumstances. We still have in our central station contracts a clause that says that the fire alarm dialer has to be hooked to a POTS line, but I wonder what alternatives others are exploring. And yes, I know about IPDACT's and such, and when the power is out the central station will know when the IPDACT disappears, but if a fire occurs the customer is SOL. We're thinking radios for backup. Other ideas?
 
gadfly56 said:
Well it finally happened. During the recent weather frenzy here in New Jersey, one of our customers lost power. Some time ago they converted their phones to VoIP. With no battery backup. Annnnnd...they had a fire. Couldn't understand why the fire department didn't show up :slaphead:. It's not clear how this is particular case is going to play out, but we know that more and more customers are going to be moving away from POTS. It's clear in fact that in may locations POTS may simply not be available under any circumstances. We still have in our central station contracts a clause that says that the fire alarm dialer has to be hooked to a POTS line, but I wonder what alternatives others are exploring. And yes, I know about IPDACT's and such, and when the power is out the central station will know when the IPDACT disappears, but if a fire occurs the customer is SOL. We're thinking radios for backup. Other ideas?
Click to expand...

Cellular dialers? Getting to be common for burg.
 
Volta said:
Cellular dialers? Getting to be common for burg.
Click to expand...

That's one idea. But we are talking about a stress situation in terms of facility. How reliable might the cell towers be during a blackout? I don't know what the typical backup scheme for towers is, but I'm sure someone here does. When you're in the middle of a hurricane and wires (telephone included) are going down all over, traffic on the cell system is going to go way up. How do we make sure that the fire alarm goes through?
 
Well personally, I like copper. At home, I still have a landline. For security, I've only put in cell dialers as backup to the same. I'm newer to fire alarm, so I've never worked with radio for it, but if the copper pairs are not available, that might be the best bet.
 
Volta said:
Well personally, I like copper. At home, I still have a landline. For security, I've only put in cell dialers as backup to the same. I'm newer to fire alarm, so I've never worked with radio for it, but if the copper pairs are not available, that might be the best bet.
Click to expand...

I'm a big fan of copper also. It's true that as far as remote supervision of the dialer status is concerned IP is hands down a winner. Trouble notification in 60 seconds instead of 24 hours (with dual line failure). But if your copper goes back to the CO it's supervised (I believe) and has battery backup for 24 hours. The problem is that you may have copper on the pole, but a few blocks up the street it converts to fiber which will have 8 hour backup if you're lucky. More like 2-4.
 
gadfly56 said:
That's one idea. But we are talking about a stress situation in terms of facility. How reliable might the cell towers be during a blackout? I don't know what the typical backup scheme for towers is, but I'm sure someone here does. When you're in the middle of a hurricane and wires (telephone included) are going down all over, traffic on the cell system is going to go way up. How do we make sure that the fire alarm goes through?
Click to expand...

If the POTS line happens to have some overhead cables it too could go down because of weather related disasters. If underground it could wash out from flooding and you lose service.

Why would you wait for fire alarm to call instead of trying to call yourself, especially after a widespread disaster when you know some services are possibly not working.
 
kwired said:
If the POTS line happens to have some overhead cables it too could go down because of weather related disasters. If underground it could wash out from flooding and you lose service.

Why would you wait for fire alarm to call instead of trying to call yourself, especially after a widespread disaster when you know some services are possibly not working.
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With the blackout, everyone had left.
 
gadfly56 said:
With the blackout, everyone had left.
Click to expand...

With wide spread blackout, what would be left, satellite phone? I know we have systems developed that in case of a man overboard you have a small satellite transmitter on your vest to send an SOS and they can be located, why not develop a system for fire or burg that can send the location info coded in the transmission the same way?
 
RICK NAPIER said:
Here is a link to a NJ DCA letter describing which phone systems are NFPA 72 compliant.
http://www.nj.gov/dca/divisions/codes/alerts/pdfs/fire_alarm_transm_channels_mfvns_11-01_10.pdf
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Rick, thanks for the link. I'm actually familiar with this document. What isn't addressed pretty much anywhere by anyone is, bottom line, how do we get the signal to the fire department? It's great that MFVN's will allow a chain of transfer, but nobody is saying "Hey, you all must guarantee xx hours of self-contained power to get the signal out," where xx is something reasonable, and anything less than 24 is not reasonable, IMHO. There is a TIA that reduces the backup time for MFVN's to 8 hours for field installed devices under NFPA 72 (2010).

The more hands that touch the signal, the more likely something will go wrong. I guess a whole lot of people will have to die before they really take a look at the issue.
 
Here almost all FACPs are connected twice.

Once via a master box and municipal hard lines (or radio) back to the fire station and another time via phone lines to a central station which are often not POTs lines. More and more are going cellular.
 
iwire said:
Here almost all FACPs are connected twice.

Once via a master box and municipal hard lines (or radio) back to the fire station and another time via phone lines to a central station which are often not POTs lines. More and more are going cellular.
Click to expand...

Some times the old ways were better than we knew!

The problem as I see it nowadays, is that transmitting an alarm signal is mostly piggybacking on the general communication infrastructure. When things start to really head south, that infrastructure gets stressed all over. So for the odd, isolated small scale infrastructure failure (eg. bad customer head end) the fall-over plan is fine, but when everyone tries to use the cellular system, say, you might not get through at all or in time to avert serious property loss or loss of life.
 
No matter what you have, it could go down in a widespread flood.

I would bet cell is substantially more reliable than VOIP, but wire maybe more than cell.
 
If you want truly reliable try redundant communication paths. No not just two phone lines.

A Wireless Mesh Network is a wonderful system, if available. Read about at AES Intellinet

Then try a UL864, NFPA 72 compliant cell communicator that is on the AT&T cell data network. The cell network is DOD compliant. The DSC GSM3055ICF costs less than $250.00, of course the 5 min supervision window will raise the cost of monitoring, but it works!

Nothing is foolproof, but the combination of these two are great for high risk applications, and no relying on external wiring that is prone to failure in inclement weather. In fact either one of these is listed for standalone commercial fire.
 
gadfly56 said:
Some times the old ways were better than we knew!

The problem as I see it nowadays, is that transmitting an alarm signal is mostly piggybacking on the general communication infrastructure. When things start to really head south, that infrastructure gets stressed all over. So for the odd, isolated small scale infrastructure failure (eg. bad customer head end) the fall-over plan is fine, but when everyone tries to use the cellular system, say, you might not get through at all or in time to avert serious property loss or loss of life.
Click to expand...

The cell radios for alarm panels, in general, are on the data backbone channels, not cell voice. That's why the signal strength is required to be at a certain dB level, to protect it from degrading for whatever reason, too far and not work. They are high priority data packets on the network, behind gov't communications and other super secret ones. When the system gets stressed, those packets are still taking priority over my text messages and forum posts from my Iphone. In fact 72 requires confirmed transmission within 90 seconds and 200 second supervision of the transmission channel (ie heartbeat). If it goes down, someone knows in less than 5 min.
 
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Honeywell Power has the IPGSM-COM that uses internet primary and GSM back up.
Honeywell (old Ademco) has the IGSMCF that uses internet primary and GSM back up.
Firelite and Silent Knight have a version of the IPDACT that uses internet primary with no back up.
Telular has the TG7FS that is GSM radio only with no backup.

Even if the unit is listed for no backup, I prefer a backup for obvious reasons. So what if the central station knows the supervision was lost within 5 minutes. What they won't know is it was lost due to a lightning strike that start the fire that burns down the building and hurts or kills people.
 
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