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Fire communicator connecting to a T1?????

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  • Fire communicator connecting to a T1?????

    First time dealing with this. Customer is bringing a T1 into the building. As I understand the line then uses a piece of equipment to separate the line into up to 20+ voice and data lines. They are providing me 2-lines downstream of this separator. The lady fire marshals boyfriend is in the telecom business and has convinced her that this is equal to POTS lines. They are installing per the fire departments requirements a 24 hour back up power supply on the separator. I am expected to use these lines, and monitor the back up power supply for failure. I believe this is no different than a local phone switch and is prohibited. Anyone else with any experience with this?
    Thanks
    Louis

  • #2
    It is against NFPA 72 National Fire Alarm Code - Section 8.5.3.2.

    See the following link:

    http://www.nfpa.org/itemDetail.asp?c...%20The%20Alarm

    It is the second question on the page.

    Comment


    • #3
      The T1 link will in all probability be a 30/25 channel 2Mb multiplexed cable carrier system which can provide 30/25 POTS type circuits. The dc voltage required to operate these lines does not originate from the wire centre as required in the regulations but rather from the remote end of the carrier system. So in essence it not much different to a local phone switch except that is doesn't carry out any switching function, this is still done at the wire center (exchange). Having both primary and secondary lines on the same system may not meet the requirements for redundancy as a failure of the multiplex system would result in the failure of both lines. It is also a bit concerning to note that you are tasked with monitoring the standby power arrangements for the remote end of the carrier system. Ordinarily this would automatically be monitored by the provider of the service by way of the service and system status channel. This places the responsibility of the maintenance of this power system on your shoulders. You could, I suppose, connect the power status alarms on to the defect inputs of the fire alarm panel but this again takes the responsibility of the power system from the service provider.
      As stated by Rooney, this configuration appears to be at a variance to the regulations.
      Here in NZ we use a standard land line POTS as the primary and a cellular line as the secondary, this ensures that the complete failure of one transmission medium does not cause the failure of both primary and secondary lines and a failure of any one of these lines is transmitted as a comms problem to the central station by way of the other line.
      Last edited by Ian; 09-22-2007, 01:56 AM.

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      • #4
        If you're monitoring the power that provides your phone lines, how do you report a problem if the power takes out the phone lines?
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        Rocket Science
        Making everything else look simple, since 1958.


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        The Future. It isn't what it used to be.

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        • #5
          I should imagine in this case you would monitor the status of the standby power only and the presence of primary power. If the primary power failed then the backup would come in and the failure of the primary power could still be communicated including any low volts status of the back up batteries, as you correctly state if both power supplies fail or a critical part of the multiplexer then there will be no phone lines to report on. This is always going to be a problem with circuits that use phone lines, seize and dial the number and carry out a single test function every 24 hours, you can easily have a situation where you have no comms with the unit for a period of 23 hours and not know it. Imagine what would happen if the building burned to the ground during this period, the fire panel would work but it wouldn't be able to communicate. The safety of the building and its occupants would lie solely on the shoulders of the people responsible for the maintenance of the T1 system.
          Ideally you would want the fire panel connected to a leased line that is continually polled by the central station and uses a different transmission medium for the secondary line. Using the inter/intranet for this type of redundancy might be a way to go as you can poll this all the time.

          Comment


          • #6
            Thanks for the info on the fire-T1 connection.

            Thanks all for the assistance. Anyone else have any comments? Now I remember that the fire marshall and her boyfriend believed that something she read in the 72 2007 handbook allowed the T1 connection. I have the 72 2007 code book and see nothing referencing a T1 line. My only guess is there may be something they believe under the 8.6.2.2 "Alternate Methods" that approved the use of a T1. What I know for sure is before I start trying to convince her she is wrong i'd better be right. She stated in front of 10 people in the project meeting on Wednesday that it was approved for me to use. I always make a habit of trying not to irritate a fire marshall who will be actively involved with all phases of my fire alarm installation.
            Thanks again, Louis

            Comment


            • #7
              Agree with your last sentence there. Irrespective of the outcome it would be recommended that the issue of who is responsible for monitoring the status of the standby power for the remote end of the T1 be sorted out. As i indicated before this is normally the responsibility of the people who provide the service on the T1 and not those who manage and maintain the fire protection equipment. If it does end up being you don't loose sight of the fact that this st by power supply provides back up for all of the lines on the T1 and not just the ones that you will be using so any costs should be divided between the services on the system.
              Good luck with your project.

              Comment


              • #8
                Yea, you don't want to piss off the FM, you're going to have to work with them again. I've had many instances where they've been wrong, not just accidently, not knowing something themselves. But times when they want to enforce things that are not code at all. They forget that they can only enforce adopted code, not make up their own. In those cases, I inform the customer, but tell them its their battle. They understand I have to work with the FM all the time. I try and work it out with the FM 1st, but I'm not going to war over it. Anyway, off that rant, as it can go on and on.

                I would make sure you document with your customer that the FM has approved the T1, etc, but it may not be to code. If the building burns down, the insurance company may be asking. You want to cover your butt.
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                Rocket Science
                Making everything else look simple, since 1958.


                http://my.opera.com/integrator/blog/
                One Man's Opinion

                The Future. It isn't what it used to be.

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                • #9
                  If you have a leased dedicated phone line, I'd invest in good line supervision. Time Division Multiplexing or Frequency Division Multiplexing are good choices provided they provide constant key and if interrupted, do not revert to "0" binary and start again. Ensure you determine the quality of the line. There is nothing so frustrating as trying to send high quality data over a line you later find out is little more than barbed wire wrapped in linen. Most service providers will tell you up front what the quality of line service you will need to support their system.
                  Enjoy the day,
                  Bill

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                  • #10
                    Originally posted by Bill Warnock View Post
                    There is nothing so frustrating as trying to send high quality data over a line you later find out is little more than barbed wire wrapped in linen.
                    Ha-ha. That's a good one Bill! I knew you were a senior member, but I had no idea.
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                    Rocket Science
                    Making everything else look simple, since 1958.


                    http://my.opera.com/integrator/blog/
                    One Man's Opinion

                    The Future. It isn't what it used to be.

                    Comment


                    • #11
                      Originally posted by integrator97 View Post
                      Ha-ha. That's a good one Bill! I knew you were a senior member, but I had no idea.
                      Integrator, when the military tried to install J-SIIDS into arms rooms and later FIDS into other high priority areas they had nuisance and false alarms galore. Problem, older military installations had not upgraded their telecommunications lines since WWII or in extreme cases, WWI. When you read the installation manual the minimum Bell Grade was clearly specified. The existing infrastructure was little better that "Telegraph Grade," and the leadership gave it little thought because it had worked in the past, so why not in the future? Some parts of the country where they had regional or in some cases, city or county phone companies, upgrade was beyond their vision.
                      When some commanders gets their pin feathers singed, they in turn to burn their subordinates. When it is explained to them, "Sir this was a Corps of Engineer program spurred by Congress after unmanned or unalarmed National Guard Armories were broken into." They calm down a bit, not much, though. The same goes for the private sector.
                      That is what prompted my response.
                      Enjoy the day,
                      Bill

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                      • #12
                        Bill,
                        I know what you mean. I don't go back as far as you, but I was Navy for 9 years, and spent my last few at Naval Weapons Station Concord, Ca. There was a lot of old stuff there, hundreds upon hundreds of bunkers, with old communications back to post 1. Half the time it didn't work, and the civilian workers would get tired of it and just open 'em up and set off the alarms. Then you've got reaction forces on the way and the whole nine yards.
                        sigpic
                        Rocket Science
                        Making everything else look simple, since 1958.


                        http://my.opera.com/integrator/blog/
                        One Man's Opinion

                        The Future. It isn't what it used to be.

                        Comment


                        • #13
                          Originally posted by integrator97 View Post
                          Bill,
                          I know what you mean. I don't go back as far as you, but I was Navy for 9 years, and spent my last few at Naval Weapons Station Concord, Ca. There was a lot of old stuff there, hundreds upon hundreds of bunkers, with old communications back to post 1. Half the time it didn't work, and the civilian workers would get tired of it and just open 'em up and set off the alarms. Then you've got reaction forces on the way and the whole nine yards.
                          Integrator, what happened during a DOD TPI? NWS Newport, had communications gear and EE-8s and MoslerXXXXXX (you'll know). One civilian SW Tech, opening an igloo, not on the Marine Guard Company's list for the day and the tech was not wearing the required over cover. When challenged by the Marine sentry, his middle finger on his right had went up and he sentry put a M-14 round through his heart. His finger was still in the extended position when response forces got there.
                          Within 24-hours, NAVEX Charleston was installing new wiring and upgrading the head-end gear.
                          The Marine was picked up by Carlos Hathcock to work at Quantico.
                          Enjoy the day,
                          Bill

                          Comment


                          • #14
                            Believe it or not on the barbed wire!

                            Originally posted by Bill Warnock View Post
                            If you have a leased dedicated phone line, I'd invest in good line supervision. Time Division Multiplexing or Frequency Division Multiplexing are good choices provided they provide constant key and if interrupted, do not revert to "0" binary and start again. Ensure you determine the quality of the line. There is nothing so frustrating as trying to send high quality data over a line you later find out is little more than barbed wire wrapped in linen. Most service providers will tell you up front what the quality of line service you will need to support their system.
                            Enjoy the day,
                            Bill
                            The State of Texas sold 3,000,000 acres of land to build the State Capital in Austin in about 1880. This ranch called the XIT (10-counties in texas)fenced the perimeter- about 780 miles round trip with barbed wire. The first phone service in about 1885 used the barbed wires for the telephone lines from Tascosa to the ranch headquarters.

                            Comment


                            • #15
                              Originally posted by [email protected] View Post
                              The State of Texas sold 3,000,000 acres of land to build the State Capital in Austin in about 1880. This ranch called the XIT (10-counties in texas)fenced the perimeter- about 780 miles round trip with barbed wire. The first phone service in about 1885 used the barbed wires for the telephone lines from Tascosa to the ranch headquarters.
                              Louis that was not a fatuous posting. They used barbed wire wrapped in linen. The same company who made the barbed wire, made this special run for several military installations, they only eliminated the barbs. Early telegraph lines were not much better.
                              Good line supervision cannot exist when every 10-bits of data have a faulty parity count. Noise on the line caused by any number of things including dampness raise havoc.
                              Enjoy the day,
                              Bill

                              Comment

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