ANSUL system

[GG]

Does anyone have a wiring schematic for an ansul system? I will be assisting someone in installing one and would like to study the ins and outs of them before the job.

 

[480sparky]

There's no single way of doing it. You could use shunt trip breakers, a contactor box, or the hood manufacturer may supply you with a control box.

Is the system a wet or dry one?

 

[e57]

I like to put in a small sub-panel just for the affected items under the hood off of a gutter to the panel they would be fed from and shunt-trip the feeder for it. While the shut off of equipment is one aspect - the HVAC is another. The part that gets me from time to time is smoke evacuation and make up air - and oh, the fire dampers.

Check which if any edition of NFPA 96 you might be on... As well as any other fire or building codes you might be on...

 

[LarryFine]

Does anyone have a wiring schematic for an ansul system? I will be assisting someone in installing one and would like to study the ins and outs of them before the job.

I have to run, but I'll be back with info later. Meanwhile:

List all under-hood electrical loads.
If gas, will there be a reset box?
New or existing installation?
Each fan's voltage, current, phase.
Same info for supply circuits.
Must lights shut down?
List switches (exhaust, make-up, lights)

 

[gadfly56]

I like to put in a small sub-panel just for the affected items under the hood off of a gutter to the panel they would be fed from and shunt-trip the feeder for it. While the shut off of equipment is one aspect - the HVAC is another. The part that gets me from time to time is smoke evacuation and make up air - and oh, the fire dampers.

Check which if any edition of NFPA 96 you might be on... As well as any other fire or building codes you might be on...

What method do you use to supervise the voltage to the shunt coil?

 

[e57]

What method do you use to supervise the voltage to the shunt coil?

Method? Surpervision? I don't think either apply - if so enlighten me...

Most of the systems have a number of NC/NO relays - and in a few cases I had to add a relay for it... Instead of shunt tripping 6-12 breakers - I shunt trip the feeder to a small panel with only the stuff under the hood that needs to be shut off. (Depending on the mood of the Fire Marshall or so it would seem*) The operation of many is that they want the exaust full on, dampers closed, make-up air open. So what I do, (depending on control voltage of the relays) is tap the coil voltage of the exaust fan, or add a relay to get 120v for the shunt coil via what ever the coil voltage is, since most of them with 24v coil voltage are fed with 120v - I use that circuit for the shunt voltage.

Anyway this set-up leaves you with a reset for the ansul system that also resets the voltage to the shunt, and only one shunt trip to reset in one location - rather than hunting down all of the shunts that might even be in different panels... Also the opprotunity to just bring one feeder over to the hood, as opposed to a bunch of circuits shunted eslewhere. And put the "hood panel" right there under/near the ansul system if you want/can.

The alternative is contactors for all of the equipment...

(*Something I have never seemed to nail down - is sometimes the idea of the operation seems to change place to place, and inspector to inspector on what the system does in reguards to HVAC - what gets shut down and what goes on - what gets cloased, what gets opened - so I do my best to get someone else to determine and decide that... )

 

[gadfly56]

Method? Surpervision? I don't think either apply - if so enlighten me...

Most of the systems have a number of NC/NO relays - and in a few cases I had to add a relay for it... Instead of shunt tripping 6-12 breakers - I shunt trip the feeder to a small panel with only the stuff under the hood that needs to be shut off. (Depending on the mood of the Fire Marshall or so it would seem*) The operation of many is that they want the exaust full on, dampers closed, make-up air open. So what I do, (depending on control voltage of the relays) is tap the coil voltage of the exaust fan, or add a relay to get 120v for the shunt coil via what ever the coil voltage is, since most of them with 24v coil voltage are fed with 120v - I use that circuit for the shunt voltage.

Anyway this set-up leaves you with a reset for the ansul system that also resets the voltage to the shunt, and only one shunt trip to reset in one location - rather than hunting down all of the shunts that might even be in different panels... Also the opprotunity to just bring one feeder over to the hood, as opposed to a bunch of circuits shunted eslewhere. And put the "hood panel" right there under/near the ansul system if you want/can.

The alternative is contactors for all of the equipment...

(*Something I have never seemed to nail down - is sometimes the idea of the operation seems to change place to place, and inspector to inspector on what the system does in reguards to HVAC - what gets shut down and what goes on - what gets cloased, what gets opened - so I do my best to get someone else to determine and decide that... )

I'll have to hunt for it, but an AHJ explained it thus:

Him:
"You have a life safety system where the shunt coil is powered from some source other than the equipment being shut down. If power to the shunt coil is lost, it will not operate as required. How do you know if there is always power to the shunt coil?"

Me:
"Normally open contactors sound good to me."

You could use a contactor to feed the panel you might otherwise put a shunt on.

 

[e57]

I'll have to hunt for it, but an AHJ explained it thus:

Him:
"You have a life safety system where the shunt coil is powered from some source other than the equipment being shut down. If power to the shunt coil is lost, it will not operate as required. How do you know if there is always power to the shunt coil?"

Me:
"Normally open contactors sound good to me."

You could use a contactor to feed the panel you might otherwise put a shunt on.

This would be my answer:

Him:
"You have a life safety system where the shunt coil is powered from some source other than the equipment being shut down. If power to the shunt coil is lost, it will not operate as required. How do you know if there is always power to the shunt coil?"

Me:
'How would you know there is power to operate the exaust fan? Or any other part of the ansul system? The shunt trip voltage is the same control circuit feeding the ansul system.'

You could use a contactor to feed the panel you might otherwise put a shunt on. But that is a beast of a contactor, or you could use multiple contactors - but that could be a lot of contactors. You could use an undervoltage trip unit instead of shunt - but it would trip on every power failure. Many people use multiple shunt trips - if what you are implying is true - all of them would be wrong too...

 

[gadfly56]

This would be my answer:

Him:
"You have a life safety system where the shunt coil is powered from some source other than the equipment being shut down. If power to the shunt coil is lost, it will not operate as required. How do you know if there is always power to the shunt coil?"

Me:
'How would you know there is power to operate the exaust fan? Or any other part of the ansul system? The shunt trip voltage is the same control circuit feeding the ansul system.'

You could use a contactor to feed the panel you might otherwise put a shunt on. But that is a beast of a contactor, or you could use multiple contactors - but that could be a lot of contactors. You could use an undervoltage trip unit instead of shunt - but it would trip on every power failure. Many people use multiple shunt trips - if what you are implying is true - all of them would be wrong too...

But the ANSUL system is mechanically operated. If there is no power to it, the appliances will still operate, unless I misunderstand your original post (not impossible) and you haven't directly answered the AHJ's concern. How can you be sure the coil has power? For sure if that circuit is out for some reason the restaurant owner won't know until he either has a fire and the appliances don't shutdown or the ANSUL service guy trips the control head during the semi-annual inspection and obtains the same result.

The fact that there may be a whole lot of shunts out there unsupervised doesn't impress me (favorably). The one possible work-around is if you tap the coil supply off one of the ungrounded conductors on the shunt trip breaker. As long as the breaker is powered up, you'll have coil power.

 

[e57]

But the ANSUL system is mechanically operated. If there is no power to it, the appliances will still operate, unless I misunderstand your original post (not impossible) and you haven't directly answered the AHJ's concern. How can you be sure the coil has power? For sure if that circuit is out for some reason the restaurant owner won't know until he either has a fire and the appliances don't shutdown or the ANSUL service guy trips the control head during the semi-annual inspection and obtains the same result.

The fact that there may be a whole lot of shunts out there unsupervised doesn't impress me (favorably). The one possible work-around is if you tap the coil supply off one of the ungrounded conductors on the shunt trip breaker. As long as the breaker is powered up, you'll have coil power.

The suppression gas is mechanical - the electrical portion is well - electrical... If there is no power - No power for the system. And likely there is no fan or other electrical portion. Sure the dampers fail closed by spring operation if there is no power.

Like I said - I don't think supervision is required for this portion of the system - on the FA side, if any - yes... But not on the equipment shut down.

But if shunt tripping concerns you - don't eat anywhere that these are installed...
http://www.captiveaire.com/CatalogC...ditional_Information/CORE_Install_Summary.pdf
http://www.springairsystems.com/literature/manual/firesuppression/Wet.pdf
http://www.greenheck.com/media/pdf/kitchen/Wiring_WaterwashArrg.pdf

 

[gadfly56]

The suppression gas is mechanical - the electrical portion is well - electrical... If there is no power - No power for the system. And likely there is no fan or other electrical portion. Sure the dampers fail closed by spring operation if there is no power.

Like I said - I don't think supervision is required for this portion of the system - on the FA side, if any - yes... But not on the equipment shut down.

But if shunt tripping concerns you - don't eat anywhere that these are installed...
http://www.captiveaire.com/CatalogC...ditional_Information/CORE_Install_Summary.pdf
http://www.springairsystems.com/literature/manual/firesuppression/Wet.pdf
http://www.greenheck.com/media/pdf/kitchen/Wiring_WaterwashArrg.pdf

Okay, maybe I'm not familiar with the ANSUL systems you've worked on. Let me walk through this and let's see where we go.

The ANSUL system has manual and automatic means of activation.

If you yank on the pull station, a stainless steel cable runs back to the AutoMan regulator assembly tripping the control head which mechanically changes the state of the microswitches attached thereto. It also dumps the gas cartridge into the agent cylinder, forcing the wet agent through the piping system.

The automatic means are a fusible link with a eutectic bridge which melts at a pre-set temperature, usually 360, 450 or 500 degrees Farenheit. This releases the tension on a stainless steel cable which runs back to the AutoMan etc etc.

The gas valve is held open via a stainless steel cable which runs back to the control head. When the control head operates it releases tension on the cable and the valve closes mechanically.

I could take an ax the the service entrance cable (wearing suitable arcflash protective gear ), walk into the kitchen, pull the pull cable or sever a fusible link and the ANSUL system will work fine. It does not require electrical power to operate.

Yes, the fan will be off. And yes, if you have a solenoid operated gas valve, it will be off as well. And yes, the ANSUL system could be electrically operated, but it doesn't have to be. And neither are Badger, Amerex, Kidde, Range Guard and PyroChem. And even if it were electrical, nothing prevents the electrician from wiring multiple sources. Not a good idea, but not impossible, so you could loose the shunt coil and nothing else.

And note, if the power for the ANSUL were from a single source and it was cut, the one thing that would still operate are all the electrical appliances! Cooking away without exhaust (I've personally seen this) with no fire protection. And I've gone to premises where the shunt coil power came from a breaker in another panel, said breaker being off and the shunt being inactive.

I did have an AHJ force the shunt to be supervised. And I think that beyond what the code may or may not require, it's the right thing to do. In the end, if a shunt isn't supervised, you do not know if it will work.

By the way, thanks for the links. I added all those PDF's to my personal collection on kitchen suppression systems .

 

[e57]

~~

The ANSUL system has manual and automatic means of activation.

If you yank on the pull station, a stainless steel cable runs back to the AutoMan regulator assembly tripping the control head which mechanically changes the state of the microswitches attached thereto. It also dumps the gas cartridge into the agent cylinder, forcing the wet agent through the piping system.

The automatic means are a fusible link with a eutectic bridge which melts at a pre-set temperature, usually 360, 450 or 500 degrees Farenheit. This releases the tension on a stainless steel cable which runs back to the AutoMan etc etc.

The gas valve is held open via a stainless steel cable which runs back to the control head. When the control head operates it releases tension on the cable and the valve closes mechanically.

I could take an ax the the service entrance cable (wearing suitable arcflash protective gear ), walk into the kitchen, pull the pull cable or sever a fusible link and the ANSUL system will work fine. It does not require electrical power to operate.

~~~

I did have an AHJ force the shunt to be supervised. And I think that beyond what the code may or may not require, it's the right thing to do. In the end, if a shunt isn't supervised, you do not know if it will work.

By the way, thanks for the links. I added all those PDF's to my personal collection on kitchen suppression systems .

Here is where we diverge - the suppression and supervision of FA are seperate... The supression is mechanical. The FA is supervised contacts for alarm responce. The shut-downs of equipment and power up of any required fans (if applicable) IMO do not require supervision - if there is no power to the building or the ansul they dont operate anyway...

Take a peak at page 5 top left... In this instance it drops power to the gas, and trips the electric via a shunt - if you were concerned about this manufacturer suggested installation you and your AHJ could take it up with them - or - use an undervoltage trip instead of a shunt. But like I said - I'm pretty sure 'supervision' is not required... As suggested by the diagrams of the other two manufacturers I linked to.


And the following is from a design spec for LA schools

k.

Kitchen equipment and exhaust hoods. All electrical equipment under

kitchen hoods shall be automatically disconnected upon activation of
the fire suppression systems.
​

​

l. ​

​

Provide a separate branch circuit for the fire suppression Ansul

System installed in kitchen hoods. If Ansul System is activated, power
to all electrical appliances under kitchen hood shall be automatically
disconnected. Appliance circuits shall be wired thru shunt trip circuit​

breakers or contactors that are interlocked with the Ansul System.
​

REF

I know you see a contradiction in it - but it is very common....
​

 

[GG]

Take a peak at page 5 top left

Thanks for the wiring diagram.

 

[e57]

Take a peak at page 5 top left

Thanks for the wiring diagram.

Credit due to what it is - It is not mine, that is the suggested use and installation concept of the manufacturer of that particular equipment - others may vary.

 

[One-eyed Jack]

This would be my answer:

Him:
"You have a life safety system where the shunt coil is powered from some source other than the equipment being shut down. If power to the shunt coil is lost, it will not operate as required. How do you know if there is always power to the shunt coil?"

Me:
'How would you know there is power to operate the exaust fan? Or any other part of the ansul system? The shunt trip voltage is the same control circuit feeding the ansul system.'

You could use a contactor to feed the panel you might otherwise put a shunt on. But that is a beast of a contactor, or you could use multiple contactors - but that could be a lot of contactors. You could use an undervoltage trip unit instead of shunt - but it would trip on every power failure. Many people use multiple shunt trips - if what you are implying is true - all of them would be wrong too...

The ansul system does not require power to operate. Thermal link and cable pull will operate all necessary "ansul components" Exhaust fan shut down is not required,make-up air only. This is used on a daily basis and they would know first thing that morning that it did not work. If the shunt trip power source is not tied to a fire alarm or some other type of monitor to alert when off it would not be allowed.

 

[e57]

~~~If the shunt trip power source is not tied to a fire alarm or some other type of monitor to alert when off it would not be allowed.

As mentioned - the power for the shunt is the same power for all other controls in the electrical portion of the ansul controls for monitoring and other function outside of the suppresion system - the one controlling fan, dampers, gas shut off, and other functions. If none of that is powered the NC/NO contacts for the FA change state sending a 'trouble' to the FA panel. So from an FA side - if any not all buildings require that here - it is monitored.

What gadfly56 seems to be saying, and you too, is that the very end of the shunt trip circuit would need to be monitored. Or do not use a shunt and fail safe/open in another method.* Which I do not believe to be the case... As stated it is very common and suggested in a lot of manufaturer literature for listed controls.... If you know otherwise - please quote a code - I'm willing to learn if you know something I dont...

*and that too can be done with an undervoltage trip unit instead.

 

[One-eyed Jack]

As mentioned - the power for the shunt is the same power for all other controls in the electrical portion of the ansul controls for monitoring and other function outside of the suppresion system - the one controlling fan, dampers, gas shut off, and other functions. If none of that is powered the NC/NO contacts for the FA change state sending a 'trouble' to the FA panel. So from an FA side - if any not all buildings require that here - it is monitored.

What gadfly56 seems to be saying, and you too, is that the very end of the shunt trip circuit would need to be monitored. Or do not use a shunt and fail safe/open in another method.* Which I do not believe to be the case... As stated it is very common and suggested in a lot of manufaturer literature for listed controls.... If you know otherwise - please quote a code - I'm willing to learn if you know something I dont...

*and that too can be done with an undervoltage trip unit instead.

IMO this meets the monitor requirement. By saying alarm I may have implied audible. My mistake.

 

[e57]

IMO this meets the monitor requirement. By saying alarm I may have implied audible. My mistake.

Yes - thats what I figure too - if I remember correct many of these have seperate contacts for the pull wire for the gas/liquid and covered for monitoring (if required) that way as well.

 

[gadfly56]

As mentioned - the power for the shunt is the same power for all other controls in the electrical portion of the ansul controls for monitoring and other function outside of the suppresion system - the one controlling fan, dampers, gas shut off, and other functions. If none of that is powered the NC/NO contacts for the FA change state sending a 'trouble' to the FA panel. So from an FA side - if any not all buildings require that here - it is monitored.

What gadfly56 seems to be saying, and you too, is that the very end of the shunt trip circuit would need to be monitored. Or do not use a shunt and fail safe/open in another method.* Which I do not believe to be the case... As stated it is very common and suggested in a lot of manufaturer literature for listed controls.... If you know otherwise - please quote a code - I'm willing to learn if you know something I dont...

*and that too can be done with an undervoltage trip unit instead.

Ahhh!!! Now I see our disconnect. If the electrical portion of the Ansul system is not powered, it will NOT send a signal to the FA panel. It will only send a signal if the control head is mechanically released! The microswitches change state ONLY when the mechanical control head operates.

And just for grins and giggles, if you electrically power the suppression system it must be have reserve power and/or be supervised per:

NFPA 17A-2002
5.2.1.13 Electrical power shall be permitted to be used for manual activation if a reserve power supply is provided or if supervision is provided as per Section 5.3.
5.3 Supervision.
5.3.1 Where supervision of any or all of the following is provided, it shall be designed to give an indication of trouble in the following:
(1) Automatic detection system
(2) Electrical actuation circuit
(3) Electrical power supply
5.3.2 Signals indicating the failure of supervised devices or equipment shall give prompt and positive indication of any failure and shall be distinctive from signals indicating operation or hazardous conditions.

 

[e57]

Ahhh!!! Now I see our disconnect. If the electrical portion of the Ansul system is not powered, it will NOT send a signal to the FA panel. It will only send a signal if the control head is mechanically released! The microswitches change state ONLY when the mechanical control head operates.

And just for grins and giggles, if you electrically power the suppression system it must be have reserve power and/or be supervised per:

NFPA 17A-2002
5.2.1.13 Electrical power shall be permitted to be used for manual activation if a reserve power supply is provided or if supervision is provided as per Section 5.3.
5.3 Supervision.
5.3.1 Where supervision of any or all of the following is provided, it shall be designed to give an indication of trouble in the following:
(1) Automatic detection system
(2) Electrical actuation circuit
(3) Electrical power supply
5.3.2 Signals indicating the failure of supervised devices or equipment shall give prompt and positive indication of any failure and shall be distinctive from signals indicating operation or hazardous conditions.

If the ansul controls for fan and damper controls etc. is not powered it WILL send a signal to the FA system as a trouble which can be named 'No power Ansul Controls'... With no power at those controls the FA contacts open in the control box....

The heads - controled by mechanical means can be completely different contacts - not electrically controlled... Which can be named - 'Hey! there a fire in the kitchen' or what-have-you.... (But the device address number will surfice...)

And I have seen one with a linkage to the chem realease that used the same contacts on a single relay for FA - but it required battery back-up... Wasn't fond of it.