Hi,
I am very new working with fire alarm system. My company use Hochiki UL and EN listed product. I am just stared learning the system. While studying the installation manual of firenet 4127 analog addressable system there are something confused me.
In the panel there is NAC1, NAC2, NAC3 & NAC4 points where i can connect the horns/strobes using class B wiring. Am i right? If right then how many horns/bells/ strobes we can use per NAC?
We can also use SLC loop for placement of Horns/strobes/bells by using a module. Right or wrong? if right the how many devices we can use under one module and which module is used for connecting notification devices?
What is the principle of Supervised Output Module? Why SOM is used?
Please explain your expert opinions. I know lots of experts are here.
Depends on a lot of variables, including the wire gauge, wire length, and current draw of each device as well as the limitations of each NAC and combined NAC’s. In other words, there is no hard set limit.
Yes, this would be the SOM.
The SOM allows you to connect NAC’s and turn them on or off, while still supervising the circuit. These are normally used in ADA rooms where you have 2 or 3 strobes you want to activate/deactive at different times independently from the building alarm. Again, the amount of devices depends on the device’s rating, wire gauge, current draw of each device, etc… that said, normally these are high output strobes a very short distance from the module, usually there’s 2 or 3 strobes (or horn strobes, speaker strobes, etc.) per device and they’re all sitting in the same suite. Very rarely will you find configurations with more than this. If you used a normal relay to switch power on and off to these devices, then you would have no way to monitor the circuit, which is why the SOM exists.
Thanks for your reply. Can you please explain why we use SOM? Only to supervise notification devices? Can i directly connect sounder base in a SLC loop?
I am very beginner in fire detection system. If i use a automatic Sprinklers system then the basic is if there is a fire then detectors detects and send a signal to control panel that there is a fire, then control panel send a signal to notification devices to alarm. Then there should be a module to control Sprinklers system and a signal should be sent to that module from a control panel to activate the Sprinklers. Am i right or wrong please explain.
Unless you have a deluge or pre-action sprinkler system, this is not true. About the only thing you will be interfacing with a sprinkler system is monitoring for water flow, tamper switch not in the correct position, or low air condition (dry systems only). Your typical sprinkler system that you see in a building are wet or dry systems that are activated by a sprinkler head by heat. Deluge and pre-action systems are special systems reserved for industrial plants, server rooms, historical sites, etc.
Thanks to all for your expert opinions. I have some more basic questions. I am just studying the installation manual. I don’t have any practical experience. That’s why i am confused.
My company uses Hochiki UL & EN listed products. In the control panel there is 4 NAC connection points. That means i 4 loop of NAC devices? Then i place NAC devices in the SLC loop using SOM? What is the benefits of using SLC loop for placing NAC devices as there are other 4 NAC loop point in the panel?
If connect NAC devices in NAC loop rather that inside SLC loop then do i need SOM?
For manual call point placement inside SLC loop what control module is used?
As it says in the manual about the SOM:
The SOM provides a supervised 24VDC polarity reversing output on the SLC loop most commonly used for audible and visual signaling appliances or triggering a remote notification appliance circuit power expander.
Expander units are used to add NACs AND power to the control panel. They can be installed remotely in the building so wire distance and voltage drop issues are reduced.
Keep in mind the power available for NACs is limited. Each panel NAC is rated for up to 2.5 amps, however the power supply has only 4 amps available. The current used by each NAC has to be added up and cannot exceed 4 amps total. That means 4 NACs at 1 amp each. One NAC at 1.5 amps and 3 NACs at 0.8 amps. Or 2 NACs at 2 amps and 2 NACs not used. Any power consumed by devices connected to a SOM powered by the panel is also part of that 4 amps. If your NAC power adds up to more than 4 amps a NAC Extender unit is needed.
No.
According to the manual I downloaded there is an addressable manual station. I do not know if it is acceptable on your particular job site. To use a standard contact type call point there is a selection of modules shown in the manual.
5.7 FRCME-4 Input Module Wiring … 63
5.8 FRCME-S Mini Input Module (w/ Terminal Blocks) … 64
5.9 FRCME-P Mini Input Module (w/ Pigtails) … 65
5.10 FRCME-M Mini Input Module (w/ Terminal Blocks) … 66
5.11 FRCMA / FRCMA-I Input Module … 67
What is DCP-R2M - DUAL RELAY MODULE? Which devices should connect with this module?
Can Manual Call point directly connect within a SLC (i.e. like detectors are connect) loop without any module?
Suppose i am using 4 SOM in a building. To power up the SOM i need 24v DC whic i can take from control panel or from a seperate DC power supply. So, to power up all 4 SOM do i need to connect with individual power supply or i can connect 1st SOM to the power supply then next SOM connect with previous SOM then so on?
From the Firenet 4127 installation manual:
5.12 R2M Dual Relay Module Wiring
The R2M provides two separately programmable relay outputs on the FireNET 2127/4127 SLC loop. These outputs may be used for a variety of purposes including door holders, elevator recall, and other fire safety functions.
From the Firenet 4127 installation manual:
5.20 AMS Addressable Manual Pull-Station
The AMS Addressable Manual Pull-Station is an integrated device that includes an input module and a manual pull-station in a single package.
The AMS is designed to be directly connected to the FN-2127/4127 control panel SLC loop.
The NAPCO FWC-FSLC- PULL Addressable Manual Pull Station and the VES VF3029-10 Addressable Manual Pull Station are also listed in the 9th edition Firenet 4127 installation manual as compatible.
These are the ONLY manual call point in the installation manual rated for direct connection to the SLC.
Sorry but I cannot give an exact answer to such a generic question. This has to be decided by knowing what is connected to each SOM, how much current is being used, and if that is in the capability of the power supply.
Be aware that any additional power supply MUST be agency listed for fire protective service and MUST be listed for use with the 4127 panel.
NAC only can supply 4 amp only. With 4 amp current we can only connect a few horn strobe. For this circumstances if I use a relay and 24v dc power supply and connection is like that
From NAC + & - to relay coil and from relay n/o point to + of 1st horn and from relay com to negative of 1st horn and other horns are connected from 1st to another and so on. Will it work?
I know that if I use som module then I can conncet many horn within a panel. But I dont want to use som also I want to install many horn within a panel which will work automatically. So my above think is right or wrong? Can you give me a diagram of your suggestion?
Thanks
Your NAC can still only supply so much. You can’t feed horns through a relay because you can’t supervise the circuit and you can’t sync the devices, both are required.
You need to get additional NAC power supplies if you need more power. and a 4 amp circuit is going to be limited to like 200 feet of wire.
Chris+s is completely correct. You cannot just throw some relays and generic power supplies in the circuit. That is not legal and could put you and your employer in jeopardy.
If your system needs more notification power and/or more notification circuits you must use an agency listed NAC extender approved to be connected to your main panel. These are a separate box with a power supply, battery charger, batteries, and NACs. They can be installed by the main panel or remotely in the building as needed. The ones made by Hochiki are controlled and supervised by a NAC from the main panel. Because the NAC extender has its own power supply it does not draw power from the main panel. Search for a Hochiki PE-10SN as an example.
Thanks for your reply. I know this is illegal. Also i know that will not supervised. But what i posted will it work or not? I don’t know i am right or wrong. But As far i know that when detectors detects then it passes a signal towards the panel and after a mentioned time panel pass a signal to NAC and NAC will generate power through the notification devices and alarm generate. As NAC generate power, if i use this power to operate a relay which is already connected with external power supply. Then the horns connected with the power supply get power from this external power supply when the relay gets power from NAC.
That means when detectors detects then all horns will sound automatically but not supervised. Will this connection work?
you should be able to wire the NAC circuit from your FACP up to the input of your NAC extender panel to activate it and still have everything be supervised. No relay is necessary.
Basically you can run one NAC circuit from your FACP to as many of these power supplies as you need too, in order to turn them all on at once when the panel goes into alarm. You can also use one NAC extender power supply to activate another one.