Fire Alarm Bell Circuit

[muazmi02]

Do we need a separate circuit for fire alarm bell / sounders when we are designing digital addressable fire alarm system? What are the requirement as per NFPA 72 & UL set standards?

For sprinkler floor control assembly, how many interface units we require? and for what purpose?

For HVAC equipment (like package units, chillers) do we require interface units separately or present HVAC equipment control is compatible and can communicate with Fire Alarm Control Panel?

And what is the case if our packaged units/chillers are controlled through BMS and BMS is already interfaced with Fire Alarm system? Do we still require interface units for these equipment?

Thanks for your answers to aforesaid question.

Regards,

 

[gadfly56]

Do we need a separate circuit for fire alarm bell / sounders when we are designing digital addressable fire alarm system? What are the requirement as per NFPA 72 & UL set standards?

For sprinkler floor control assembly, how many interface units we require? and for what purpose?

For HVAC equipment (like package units, chillers) do we require interface units separately or present HVAC equipment control is compatible and can communicate with Fire Alarm Control Panel?

And what is the case if our packaged units/chillers are controlled through BMS and BMS is already interfaced with Fire Alarm system? Do we still require interface units for these equipment?

Thanks for your answers to aforesaid question.

Regards,

1. Yes. Only Simplex has addressable notification appliances on the market, and they still require a separate 24VDC power supply. Depending on the size of the building, you may need a great many notification zones. The maximum size for a notification zone is 23,000 square feet. You must also have separate notification zones whenever you cross a fire barrier, such as an interior fire partition on a floor, or going from floor to floor. A 100 story building needs a minimum of 100 notification zones.

2. Your guess is as good as anyone's. How many flow switches and tamper switches are there on the floor control assembly? If you have a conventional panel, you can put 5 waterflow switches on a single zone. You can put up to 20 tamper switches on a single zone. You could do the same thing with a monitor module for an addressable system, but more usually each discreet waterflow switch and tamper switch gets its own input point.

3. No HVAC equipment can talk directly to any fire alarm control panel that I know of. You will need duct detectors in the supply and return for your HVAC units. One is required by NFPA 72, the other by the International Mechanical Code (IMC; if you are a manufacturer you should know this already). I know that many RTU's and AHU's come equipped with an on-board duct detector, designed to shut down the unit when activated, usually in the supply section of the unit. This can be monitored by the fire alarm system. The return side duct detector has to go in the duct work UPSTREAM of any make up air.

4. It depends. Some BMS's are listed for fire alarm; Siemens has one. Otherwise, the fire alarm control panel (FACP) has to be in charge, not just connected to the BMS via a relay or other signal.

 

[muazmi02]

1. Yes. Only Simplex has addressable notification appliances on the market, and they still require a separate 24VDC power supply. Depending on the size of the building, you may need a great many notification zones. The maximum size for a notification zone is 23,000 square feet. You must also have separate notification zones whenever you cross a fire barrier, such as an interior fire partition on a floor, or going from floor to floor. A 100 story building needs a minimum of 100 notification zones.

2. Your guess is as good as anyone's. How many flow switches and tamper switches are there on the floor control assembly? If you have a conventional panel, you can put 5 waterflow switches on a single zone. You can put up to 20 tamper switches on a single zone. You could do the same thing with a monitor module for an addressable system, but more usually each discreet waterflow switch and tamper switch gets its own input point.

3. No HVAC equipment can talk directly to any fire alarm control panel that I know of. You will need duct detectors in the supply and return for your HVAC units. One is required by NFPA 72, the other by the International Mechanical Code (IMC; if you are a manufacturer you should know this already). I know that many RTU's and AHU's come equipped with an on-board duct detector, designed to shut down the unit when activated, usually in the supply section of the unit. This can be monitored by the fire alarm system. The return side duct detector has to go in the duct work UPSTREAM of any make up air.

4. It depends. Some BMS's are listed for fire alarm; Siemens has one. Otherwise, the fire alarm control panel (FACP) has to be in charge, not just connected to the BMS via a relay or other signal.

Thanks for your prompt reply. I'll be back soon with some detailed question.

Regards,

 

[muazmi02]

1. Yes. Only Simplex has addressable notification appliances on the market, and they still require a separate 24VDC power supply. Depending on the size of the building, you may need a great many notification zones. The maximum size for a notification zone is 23,000 square feet. You must also have separate notification zones whenever you cross a fire barrier, such as an interior fire partition on a floor, or going from floor to floor. A 100 story building needs a minimum of 100 notification zones.

2. Your guess is as good as anyone's. How many flow switches and tamper switches are there on the floor control assembly? If you have a conventional panel, you can put 5 waterflow switches on a single zone. You can put up to 20 tamper switches on a single zone. You could do the same thing with a monitor module for an addressable system, but more usually each discreet waterflow switch and tamper switch gets its own input point.

3. No HVAC equipment can talk directly to any fire alarm control panel that I know of. You will need duct detectors in the supply and return for your HVAC units. One is required by NFPA 72, the other by the International Mechanical Code (IMC; if you are a manufacturer you should know this already). I know that many RTU's and AHU's come equipped with an on-board duct detector, designed to shut down the unit when activated, usually in the supply section of the unit. This can be monitored by the fire alarm system. The return side duct detector has to go in the duct work UPSTREAM of any make up air.

4. It depends. Some BMS's are listed for fire alarm; Siemens has one. Otherwise, the fire alarm control panel (FACP) has to be in charge, not just connected to the BMS via a relay or other signal.

1. It means only simplex can supply addressable notification appliances (bells) and if we put addressable notification appliances in our system specifications, then it becomes monopoly and many vendors are by default out from the competition. And other reason is that UL/NFPA requirement does not include the addressable notification appliances. We should put them on separate circuit and each zone should have separate circuit.

2. What i understand from your answer is that we should provide interface units for each flow control and temper switch. And instead of wiring them in main detectors loop, we should provide separate circuit for each zone. Maximum water 5 water flow switches & 20 tamper switches can be wired in one circuit. Or each flow control & tamper switch should be directly wired to FACP?

 

[gadfly56]

1. It means only simplex can supply addressable notification appliances (bells) and if we put addressable notification appliances in our system specifications, then it becomes monopoly and many vendors are by default out from the competition. And other reason is that UL/NFPA requirement does not include the addressable notification appliances. We should put them on separate circuit and each zone should have separate circuit.

2. What i understand from your answer is that we should provide interface units for each flow control and temper switch. And instead of wiring them in main detectors loop, we should provide separate circuit for each zone. Maximum water 5 water flow switches & 20 tamper switches can be wired in one circuit. Or each flow control & tamper switch should be directly wired to FACP?

With regard to the flow and tamper switches, are we dealing with a conventional panel or an addressable panel? Answer that, then we'll proceed.

 

[MisterCMK]

1. It means only simplex can supply addressable notification appliances (bells) and if we put addressable notification appliances in our system specifications, then it becomes monopoly and many vendors are by default out from the competition. And other reason is that UL/NFPA requirement does not include the addressable notification appliances. We should put them on separate circuit and each zone should have separate circuit.

2. What i understand from your answer is that we should provide interface units for each flow control and temper switch. And instead of wiring them in main detectors loop, we should provide separate circuit for each zone. Maximum water 5 water flow switches & 20 tamper switches can be wired in one circuit. Or each flow control & tamper switch should be directly wired to FACP?

Addressable NACs are a solution in search of a problem


There is no problem wiring flow and tamper modules in the data loop with detectors.

 

[peterrudart]

120v bell and flow switch

120v bell and flow switch

I need to wire a potter flow switch and a 120v bell on my job. i have my dedicated locked cicuit feedind the flow switch. the diagram shows my hot (common) to land directly to the switch and my neutral (n.o.) to go through the bell. The bell has 2 white leads and 2 black leads. if i wire my neutral through the switch where do i get my hot leg from?

 

[ryant35]

1. Yes. Only Simplex has addressable notification appliances on the market, and they still require a separate 24VDC power supply. Depending on the size of the building, you may need a great many notification zones. The maximum size for a notification zone is 23,000 square feet. You must also have separate notification zones whenever you cross a fire barrier, such as an interior fire partition on a floor, or going from floor to floor. A 100 story building needs a minimum of 100 notification zones.

2. Your guess is as good as anyone's. How many flow switches and tamper switches are there on the floor control assembly? If you have a conventional panel, you can put 5 waterflow switches on a single zone. You can put up to 20 tamper switches on a single zone. You could do the same thing with a monitor module for an addressable system, but more usually each discreet waterflow switch and tamper switch gets its own input point.

3. No HVAC equipment can talk directly to any fire alarm control panel that I know of. You will need duct detectors in the supply and return for your HVAC units. One is required by NFPA 72, the other by the International Mechanical Code (IMC; if you are a manufacturer you should know this already). I know that many RTU's and AHU's come equipped with an on-board duct detector, designed to shut down the unit when activated, usually in the supply section of the unit. This can be monitored by the fire alarm system. The return side duct detector has to go in the duct work UPSTREAM of any make up air.

4. It depends. Some BMS's are listed for fire alarm; Siemens has one. Otherwise, the fire alarm control panel (FACP) has to be in charge, not just connected to the BMS via a relay or other signal.

The Simplex addressable power supply is 29V on AC or battery... just an FYI.

 

[peter d]

Addressable NACs are a solution in search of a problem

I agree, especially when you consider the proprietary technology involved.