The venue I work in has a PA system which has been installed without any way of connecting to a fire system. I need a way to cut it off when the fire alarm goes off. There are 6 amp racks on 32A 230v feeds, or 21 line level signals from the desk. There is a separate evacuation system installed. No other functionality is needed. What is the simplest product available that will cut off the system? I was thinking some sort of multi channel line level relay, but haven't found any available to buy.
Fire Alarm Cut Off
- Thread starter Jon Pusey
- Start date
Re: Fire Alarm Cut Off
It sounds like you're looking to cut the power to the rig...have you considered utilizing the rig to relay a safety announcement or warning message? Whatever safety authority you are under (whoever does the inspections and approvals) should tell you what is/isn't required for your area of the world.
It sounds like you're looking to cut the power to the rig...have you considered utilizing the rig to relay a safety announcement or warning message? Whatever safety authority you are under (whoever does the inspections and approvals) should tell you what is/isn't required for your area of the world.
Re: Fire Alarm Cut Off
That is something you probably have to build yourself. On the line level side, a 48 pole single throw relay will give you a balanced cutoff, although a double throw with a short on the second throw might be better. Try T-Bar.
Mac
That is something you probably have to build yourself. On the line level side, a 48 pole single throw relay will give you a balanced cutoff, although a double throw with a short on the second throw might be better. Try T-Bar.
Mac
Re: Fire Alarm Cut Off
I recall when I helped the lads with the meter design in the APB Pro desk console series it had a safety feature where the normal audio gets muted and only the auxiliary alarm audio feed is active. I don't know all the details, I just worked on the meter.
I suspect there may be other pro install products with this capability it is mandatory for some venues IIRC.
JR
I recall when I helped the lads with the meter design in the APB Pro desk console series it had a safety feature where the normal audio gets muted and only the auxiliary alarm audio feed is active. I don't know all the details, I just worked on the meter.
I suspect there may be other pro install products with this capability it is mandatory for some venues IIRC.
JR
Re: Fire Alarm Cut Off
Is there some kind of system processor in line that can be prompted to change presets to one that mutes the system? It's easily done with any processor that has GPI external control inputs and can use that for muting or preset changes.
Is there some kind of system processor in line that can be prompted to change presets to one that mutes the system? It's easily done with any processor that has GPI external control inputs and can use that for muting or preset changes.
RYAN LOUDMUSIC JENKINS
Sophomore
Re: Fire Alarm Cut Off
You just need shunt trip breakers to turn of the power to the amps when a fire alarm gets off.
You just need shunt trip breakers to turn of the power to the amps when a fire alarm gets off.
Re: Fire Alarm Cut Off
There are plenty of products with this capacity, I believe most install focussed audio processors such as soundweb can do it, and that is what I would have installed were it my call. However we have to add this capability on as it was not considered in the original spec. There is an emergency pa system in place so the music system is not needed for evacuation. I already have processing for the system which is locked down so I would like to avoid any extra AD/DA conversions.
The fire alarm people would have been happy with the system being muted via GPI input on the desk, however the GPI scene recall functionality on the desk (Soundcraft VI6) does not work and I have not been told that this will be fixed anytime soon.
I like Macs suggestion, however I am not 100% confident in how to wire this up so it switches with no nasty pops. Would I be able to just wire one side of the relay as a pass through and the other side to short pins 2 + 3 together? Would this make any loud noises or be relatively silent?
There are plenty of products with this capacity, I believe most install focussed audio processors such as soundweb can do it, and that is what I would have installed were it my call. However we have to add this capability on as it was not considered in the original spec. There is an emergency pa system in place so the music system is not needed for evacuation. I already have processing for the system which is locked down so I would like to avoid any extra AD/DA conversions.
The fire alarm people would have been happy with the system being muted via GPI input on the desk, however the GPI scene recall functionality on the desk (Soundcraft VI6) does not work and I have not been told that this will be fixed anytime soon.
I like Macs suggestion, however I am not 100% confident in how to wire this up so it switches with no nasty pops. Would I be able to just wire one side of the relay as a pass through and the other side to short pins 2 + 3 together? Would this make any loud noises or be relatively silent?
Re: Fire Alarm Cut Off
I've done that with a Yamaha DME24 and a low voltage feed from the fire alarm into the GPIO input. If the alarm is triggered, the voltage drops to zero on the GPIO and the system mutes. It will also mute if someone tries to remove the connection, no voltage on the input equals no sound.
I've done that with a Yamaha DME24 and a low voltage feed from the fire alarm into the GPIO input. If the alarm is triggered, the voltage drops to zero on the GPIO and the system mutes. It will also mute if someone tries to remove the connection, no voltage on the input equals no sound.
Re: Fire Alarm Cut Off
As others have said, there MUST be a processor between the desk and amps in a system of this scale. connect a "dry contact" from the fire alarm to the processor and have it mute everything as appropriate..
if you don't have access to the processor or don't want to touch the system then the last resort is the brute-force method of killing the power to all of the amps (or the processor if that will mute the system AND if dropping power to that unit doesn't cause undesirable noises to the speakers (some units are ok with this, some very much not)
Jason
As others have said, there MUST be a processor between the desk and amps in a system of this scale. connect a "dry contact" from the fire alarm to the processor and have it mute everything as appropriate..
if you don't have access to the processor or don't want to touch the system then the last resort is the brute-force method of killing the power to all of the amps (or the processor if that will mute the system AND if dropping power to that unit doesn't cause undesirable noises to the speakers (some units are ok with this, some very much not)
Jason
Re: Fire Alarm Cut Off
Does your municipality dictate that the PA system be muted, or powered off? Does this include the monitor system as well? Generally the answer is 'no', but I have seen stranger things. Once you have these answers, this will dictate which solution will work best for you.
There are commercial products that can facilitate such contact closures. A multi-pole relay as Mac mentioned might work on the line level side, but I'm guessing it needs to be automatically triggered from fire command. Depending on your DSP, you may have GPIO ports that can be used to control various mute states. If you have to take a contact closure from a fire alarm system, be sure to check the voltage they send down the line from fire command - you may need a transformer. You mentioned that your DSP is locked down - does it even accept contact closures? If it is a newer system (warranty?), this could be cause for the contractor to come back and unlock the DSP to add functionality if it is part of life safety. Even if it is out of warranty, adding a mute state into a programming shouldn't take all that long - maybe the least expensive and most convenient option is a service call.
Does your municipality dictate that the PA system be muted, or powered off? Does this include the monitor system as well? Generally the answer is 'no', but I have seen stranger things. Once you have these answers, this will dictate which solution will work best for you.
There are commercial products that can facilitate such contact closures. A multi-pole relay as Mac mentioned might work on the line level side, but I'm guessing it needs to be automatically triggered from fire command. Depending on your DSP, you may have GPIO ports that can be used to control various mute states. If you have to take a contact closure from a fire alarm system, be sure to check the voltage they send down the line from fire command - you may need a transformer. You mentioned that your DSP is locked down - does it even accept contact closures? If it is a newer system (warranty?), this could be cause for the contractor to come back and unlock the DSP to add functionality if it is part of life safety. Even if it is out of warranty, adding a mute state into a programming shouldn't take all that long - maybe the least expensive and most convenient option is a service call.
Re: Fire Alarm Cut Off
I'll echo that it may be worth verifying what is required. Typically I have been able to mute the system via a contact closure to the system processor(s) but I have had situations where the AHJ required us to power off the amplifiers.
I'll echo that it may be worth verifying what is required. Typically I have been able to mute the system via a contact closure to the system processor(s) but I have had situations where the AHJ required us to power off the amplifiers.
While the house system may be useful for non-emergency or non-life safety announcements, unless the house system is designed and approved specifically to serve as an emergency announce system then you are usually better to not use it during emergencies as its use can potentially interfere with any other systems used for that purpose. The last thing needed is a paniced, ill advised announcement at high sound levels interfering with people hearing the needed announcement.
Re: Fire Alarm Cut Off
As far as I can tell, the local code just stipulates that the fire alarm system / voice evacuation system must override any public address systems. Not having to cut monitors would be great, although our stage is generally quite loud.
The reason I asked for a device that just cuts the line level signal is that our dsp does not have any GPI inputs. While an installation DSP would have been the obvious choice, the system is a still flightcased portable system with a couple of Linea Research processors in each rack. The system was installed by someone based in a different country where I believe the fire safety regime is less rigorous.
As far as I can tell, the local code just stipulates that the fire alarm system / voice evacuation system must override any public address systems. Not having to cut monitors would be great, although our stage is generally quite loud.
The reason I asked for a device that just cuts the line level signal is that our dsp does not have any GPI inputs. While an installation DSP would have been the obvious choice, the system is a still flightcased portable system with a couple of Linea Research processors in each rack. The system was installed by someone based in a different country where I believe the fire safety regime is less rigorous.
Re: Fire Alarm Cut Off
Does everything pass through the processors? If so, could you use a power device with a contact closure remote control functionality (SurgeX, Middle Atlantic, Furman, JuiceGoose, etc.) to switch the processor power?
Re: Fire Alarm Cut Off
You need to be careful taking on functionality of a fire system, first..........are you a licensed fire systems tech? If not ,DONT TOUCH IT ! Since this is not the U.S.OF A.,you need to find out from a licensed fire alarm company in your area to come out to inspect your layout and let them determine how this can be accomplished.This cannot be your responsibility ! The device needed for audible cutoff must be manufactured by a fire systems manufacturer.PERIOD. This device must be tested by U.L.Labs and pass all tests before being put in production.PERIOD. A LICENSED FIRE SYSTEMS TECH MUST INSTALL AND TEST. NOT YOU. This device will be wired in such a way that, for any reason, the fire panel will detect a disconnect of any type,an audible signal will be generated.... A TROUBLE SIGNAL.... and this signal is sent to the monitoring center. The monitoring center must call the location back. You do not want this heavy of a responsibility .IF ,FOR ANY REASON,A FIRE SYSTEM YOU WORKED ON HAS ANY FAILURE( LIKE YOU TYING IN SOME PART YOU THINK MIGHT WORK) AND IT FAILS ,AND PATRONS HERE DONT KNOW ABOUT A FIRE......IF THERE'S ANY LOSS OF LIFE....YOU WILL BE HELD ACCOUNTABLE.YOU CAN GO TO PRISON FOR THIS. This is not something you want. Just speaking from 26 years working on fire systems............now retired..thank GOD.
You need to be careful taking on functionality of a fire system, first..........are you a licensed fire systems tech? If not ,DONT TOUCH IT ! Since this is not the U.S.OF A.,you need to find out from a licensed fire alarm company in your area to come out to inspect your layout and let them determine how this can be accomplished.This cannot be your responsibility ! The device needed for audible cutoff must be manufactured by a fire systems manufacturer.PERIOD. This device must be tested by U.L.Labs and pass all tests before being put in production.PERIOD. A LICENSED FIRE SYSTEMS TECH MUST INSTALL AND TEST. NOT YOU. This device will be wired in such a way that, for any reason, the fire panel will detect a disconnect of any type,an audible signal will be generated.... A TROUBLE SIGNAL.... and this signal is sent to the monitoring center. The monitoring center must call the location back. You do not want this heavy of a responsibility .IF ,FOR ANY REASON,A FIRE SYSTEM YOU WORKED ON HAS ANY FAILURE( LIKE YOU TYING IN SOME PART YOU THINK MIGHT WORK) AND IT FAILS ,AND PATRONS HERE DONT KNOW ABOUT A FIRE......IF THERE'S ANY LOSS OF LIFE....YOU WILL BE HELD ACCOUNTABLE.YOU CAN GO TO PRISON FOR THIS. This is not something you want. Just speaking from 26 years working on fire systems............now retired..thank GOD.
Re: Fire Alarm Cut Off
Just to be clear, there are apparently two basic approaches to commercial/professional AV and audio integrating with life safety and ECS systems. One is an integrated approach where portions of a system serve dual purpose for both AV/audio and ECS, in which case many, but not necessarily all, of the issues noted may apply. The more traditional concept is where the life safety system is separate from the audio/AV systems and simply disables the audio and/or AV systems in such a way that they do not interfere with the proper operation or functionality of the life safety system. The latter seems to be the approach addressed here.
An interesting note, when NFPA 72 first starting addressing STI-PA and CIS requirements one of the dilemmas identified was that most licensed and otherwise qualified life safety contractors were not trained to or qualified to address the design of such systems, that expertise actually tended to lie greatly with commercial acoustical and audiovisual consultants and contractors. More recent versions of NFPA 72 have recognized the potential value of integrating commercial AV parties and products into life safety and especially ECS.
Mike, while I agree with you in regard to the design and installation of the actual life safety systems, I should note that in almost 30 years including 7 years with a design firm that also designed life safety systems I have yet to encounter the issues or qualifications you note in regards to interfacing to other audio systems. The systems providing the contact closure or other input may need to be monitored, installed by a properly licensed fire alarm contractor, etc. but in numerous projects with many different designers, contractors and AHJ I have never seen that extended to the actual muting or power control for other audio, that aspect has always been handled by the audio/AV designer and contractor. In fact, I am usually the party to broach the topic as most life safety consultants and contractors seemed oblivious to it and to have no clue of what to do.
Just to be clear, there are apparently two basic approaches to commercial/professional AV and audio integrating with life safety and ECS systems. One is an integrated approach where portions of a system serve dual purpose for both AV/audio and ECS, in which case many, but not necessarily all, of the issues noted may apply. The more traditional concept is where the life safety system is separate from the audio/AV systems and simply disables the audio and/or AV systems in such a way that they do not interfere with the proper operation or functionality of the life safety system. The latter seems to be the approach addressed here.
An interesting note, when NFPA 72 first starting addressing STI-PA and CIS requirements one of the dilemmas identified was that most licensed and otherwise qualified life safety contractors were not trained to or qualified to address the design of such systems, that expertise actually tended to lie greatly with commercial acoustical and audiovisual consultants and contractors. More recent versions of NFPA 72 have recognized the potential value of integrating commercial AV parties and products into life safety and especially ECS.
Re: Fire Alarm Cut Off
With regards to who's " job" it is to attempt to control shunting of audio systems where fire systems take precedence,you have to understand LIABILITY. You should not use devices designed for pro audio for this purpose , as was stated in numerous responses as a" fix".These are not designed for that application.And another point to consider is this : the A.H.J.'s demands on a job site,whether deemed "over the top" or not,supersede any code or rule in any fire code publication .And dont dare make any attempt to prove him wrong either . They generally dont like it! My point is this :fire systems always take precedence ,no exceptions ,and the liability of loss of life is far too steep a price to pay,cos you "think ya got it figured out" . Please call in someone from a fire alarm company .......its far too serious a point to take so lightly .You should have testing done with AHJ present,it looks far better for you ,as you will be asked to sign off on your work .Its called "cover your ass".This will state that "at the time of testing,the equipment performed as planned",Be prepared and think twice if you want that responsibility .PLEASE. NICET LEVEL 3 AND STATE FIRE LICENSE.....I EARNED THEM.
With regards to who's " job" it is to attempt to control shunting of audio systems where fire systems take precedence,you have to understand LIABILITY. You should not use devices designed for pro audio for this purpose , as was stated in numerous responses as a" fix".These are not designed for that application.And another point to consider is this : the A.H.J.'s demands on a job site,whether deemed "over the top" or not,supersede any code or rule in any fire code publication .And dont dare make any attempt to prove him wrong either . They generally dont like it! My point is this :fire systems always take precedence ,no exceptions ,and the liability of loss of life is far too steep a price to pay,cos you "think ya got it figured out" . Please call in someone from a fire alarm company .......its far too serious a point to take so lightly .You should have testing done with AHJ present,it looks far better for you ,as you will be asked to sign off on your work .Its called "cover your ass".This will state that "at the time of testing,the equipment performed as planned",Be prepared and think twice if you want that responsibility .PLEASE. NICET LEVEL 3 AND STATE FIRE LICENSE.....I EARNED THEM.
Re: Fire Alarm Cut Off
That's all well and good, but it still has little to do with the topic at hand.
That's all well and good, but it still has little to do with the topic at hand.
Re: Fire Alarm Cut Off
I have worked with numerous licensed life safety Contractors and Professional Engineers as well as various AHJs on schools, performing arts venues, corporate facilities, arenas, airports, convention centers and so on where the muting of other audio systems, including proof of performance testing, has always been addressed by the audio system designer as part of the audio systems and through the use of professional audio components. Like you said, I was not going to argue with all the AHJs that supported that approach, however I welcome any specific references in NFPA or state licensing laws that identify that aspect to be considered part of the life safety system or the purview of only licensed alarm contractors.
Neither of which necessarily makes you qualified for the work being discussed as I believe we are actually talking about the proper function of the audio system when it is not an integral part of the life safety system. As a specific example, here in Georgia a Low Voltage - General license, which covers sound systems, is separate from a Low Voltage - Alarm license, thus a licensed Low Voltage - Alarm Contractor is not actually licensed for audio and AV systems work. Apparently only someone with both Low Voltage - Alarm and Low Voltage - General licenses or a Low Voltage - Unrestricted license could address both life safety and audio system aspects.
I have worked with numerous licensed life safety Contractors and Professional Engineers as well as various AHJs on schools, performing arts venues, corporate facilities, arenas, airports, convention centers and so on where the muting of other audio systems, including proof of performance testing, has always been addressed by the audio system designer as part of the audio systems and through the use of professional audio components. Like you said, I was not going to argue with all the AHJs that supported that approach, however I welcome any specific references in NFPA or state licensing laws that identify that aspect to be considered part of the life safety system or the purview of only licensed alarm contractors.
Re: Fire Alarm Cut Off
Gentlemen...............As the OP stated,he needs to disable the venue audible...........is that correct ? We dont know if the OP was ordered by any AHJ to disable venue audible on alarm,was he asked by the venue to make this happen, or did he take this on by himself.THOSE are the questions we didn't get any answers to. My answer to this fix is :At each and every power amp input ,a 24 VOLT relay can be installed .(A 24 volt relay will be used ,because commercial fire systems operate on 24 volts ) .Picture like having a DI box at the back of each amp.This relay will open on alarm,disconnecting the hot leg so no signal passes.Each device will be mounted in such a way that removal of said device will trip the fire system into FIRE TROUBLE,so no tampering can occur.You do not have to shut down any amps ,no fooling with breakers or any 120 or 240 VAC . This relay will be wired thru a supervised output on the fire panel,thereby monitoring the connection integrity 24/7 .I am suggesting using these devices at the amps ,since the OP stated the board was meant to be removed.This also gets around the issue of attempting to use the board to mute audio for alarms , or if another board is substituted, you're still covered. To reset venue audible ,you reset the fire system. My other questions are :how much fire protection at this venue ? Are there horn/ strobes in place ? pull stations ? Is the venue have a sprinkler system? And there IS an EVAC system in place already ? And the install company that did the fire system do the EVAC also ,or another company? Was there an AHJ ever on premise before ? I FIND THIS INTERESTING............. if theres an EVAC system ALREADY in place,was the venue tested with the P.A. up and running with a sufficient level ,and do a fire drill ..........alarm system trips ,which in turn trips EVAC system ,to see what kind of an annunciation happens ? And DID IT PASS ? Did the AHJ state :" this aint gettin it , make the PA shut off"..... or what ? Now , Brad , does this address the topic at hand ? I hope so ....I just dont want to see the OP get into a situation that he cannot control , or even worse getting forced into this situation. I hope you all now understand where I'm coming from . Thanx .
Gentlemen...............As the OP stated,he needs to disable the venue audible...........is that correct ? We dont know if the OP was ordered by any AHJ to disable venue audible on alarm,was he asked by the venue to make this happen, or did he take this on by himself.THOSE are the questions we didn't get any answers to. My answer to this fix is :At each and every power amp input ,a 24 VOLT relay can be installed .(A 24 volt relay will be used ,because commercial fire systems operate on 24 volts ) .Picture like having a DI box at the back of each amp.This relay will open on alarm,disconnecting the hot leg so no signal passes.Each device will be mounted in such a way that removal of said device will trip the fire system into FIRE TROUBLE,so no tampering can occur.You do not have to shut down any amps ,no fooling with breakers or any 120 or 240 VAC . This relay will be wired thru a supervised output on the fire panel,thereby monitoring the connection integrity 24/7 .I am suggesting using these devices at the amps ,since the OP stated the board was meant to be removed.This also gets around the issue of attempting to use the board to mute audio for alarms , or if another board is substituted, you're still covered. To reset venue audible ,you reset the fire system. My other questions are :how much fire protection at this venue ? Are there horn/ strobes in place ? pull stations ? Is the venue have a sprinkler system? And there IS an EVAC system in place already ? And the install company that did the fire system do the EVAC also ,or another company? Was there an AHJ ever on premise before ? I FIND THIS INTERESTING............. if theres an EVAC system ALREADY in place,was the venue tested with the P.A. up and running with a sufficient level ,and do a fire drill ..........alarm system trips ,which in turn trips EVAC system ,to see what kind of an annunciation happens ? And DID IT PASS ? Did the AHJ state :" this aint gettin it , make the PA shut off"..... or what ? Now , Brad , does this address the topic at hand ? I hope so ....I just dont want to see the OP get into a situation that he cannot control , or even worse getting forced into this situation. I hope you all now understand where I'm coming from . Thanx .
Re: Fire Alarm Cut Off
This concept has been around for a while and there are commercial solutions available when designing new systems.
I am not enthusiastic about McGyvering a bunch or relays to amps without knowing that his particular regulations call for.
We're not talking about Kansas anymore (UAE).
JR
This concept has been around for a while and there are commercial solutions available when designing new systems.
I am not enthusiastic about McGyvering a bunch or relays to amps without knowing that his particular regulations call for.
We're not talking about Kansas anymore (UAE).
JR