@@GridForgeMFGthe max voltage for Almosr every fire alarm pull station or audible device same with visible fire alarms so like a horn strobe and pull station run on max 32 volts and all below and like 5 amps I think
Explosion proof fire alarm devices are made, so if there is frameable vapor, like gas, you can evacuate the building quickly. That yellow pull station was probably a gas leak alarm.
13:49 Typically, this will not set off the alarm, but it will cause a “trouble condition” on the fire alarm control panel (FACP). When there is a trouble condition, the FACP will start beeping, indicate the problem on its display, and possibly send a notification to an off site monitoring station. This is not meant to evacuate the building, but is meant to alert staff and maintenance personnel that there is an issue with the system and it is not fully functioning. The wires are supervised to be sure they are not broken. On simple, “conventional” systems this is done with a resistor across the circuit at the last device on the circuit. When the FACP no longer detects that resistance, it goes into trouble. An alarm is caused by a short circuit. On an addressable system, the FACP is constantly aware of every single device and is constantly polling every device on the system for its status. If the device stops responding, the FACP will go into trouble. When the device goes into an alarm condition, it will send back that message the next time the panel polls it (usually within a few seconds at most on modern systems).
Wow, thank you for the comment and information! As an outsider, I find these systems really interesting. It seems like a very cool problem to design something to be so safe, both in the hardware and programming.
@@GridForgeMFG These pulls can come in many colors and have different labels and stuff, if they aren't red and don't say FIRE or AGENT RELEASE, they are most definitely for something else.
@@GridForgeMFG You are welcome! I enjoy explaining things like this to people who are interested in learning. I also wanted to mention that, in most newer setups, you have something called a “class A wire loop”. Instead of the wires just going out to the devices in a single line, the wire goes in a loop so that both ends of the wire go back to the FACP. This means that, even if there is a break somewhere along the wire, the circuit is still connected on both ends. This will still cause a “trouble condition”, though. There are also many codes that regulate how these systems are wired and installed. In general, even though fire alarm usually runs at low voltage (normally 24vdc), it is treated the same as (or better than) high voltage wiring because it is a life safety system. The wire that they use for it is also a specific type that is rated to hold up better in extreme heat.
Just like your friend said, explosion proof pull stations aren't meant to be explosion proof, but instead, prevent explosions. Regular conventional pull stations, which this one is, run on 24 volts DC, and even though this isn't a lot of voltage, in hazardous conditions, you don't want a spark or anything igniting any flammable vapors, so that's what these pull stations are used for.
"Intrinsically safe" is the main keyword here. Anywhere you have a situation where there could be stuff in the air that's combustible (e g. Oil refinery, chemical plant, grain processing), the fire, building, HVAC, and electrical codes go bananas trying to prevent ANY chance of a spark causing an explosion. It's amazingly onerous to comply with as you've discovered with this relatively straightforward pull station (and for good reason given the risks to life and capital investment). Theres all sorts of intristincally safe devices and containers if you look around. Every company that works with industrial plants and automation a lot will have special models.
I think the button is held down and the button, once station is pulled, is let up. I think I've seen this exact pull station as a tornado alarm at a school video.
@@GridForgeMFG that is why these devices can be key tested without pulling the lever. Also why the Lever cant be reset without opening it. The button prevents it. I have a few t-bars myself and I've used them many times.
@@GridForgeMFGmost likely this is a normally closed switch, such as a kill switch, which are typically yellow. This would also explain why the pull station would need to be intrinsically safe.
Fire code requires fire alarm pull stations to require a tool to reset as they are meant to be latching devices. Which could either be a hex key, screwdriver, or a key.
As a fire alarm collector, the keys are for as you said, to tell if it’s pulled or not. But it’s also a security and safety function. Your pull station has a toggle button. When pressed, it’s normal, when the button is pressed out, it’s activated. If the pull stations didn’t have a key, you can kinda foreshadow the outcome. Great video!
Not only is this designed so that any spark from the switch will not see off an explosive environment around it, there is a second layer to the design. The box is so sturdy that if the seals fail and the flammable/explosive vapor leaks into the box and gets set off, the box is sturdy enough to contain the explosion and prevent it from setting off the whole environment. That's the intrinsically safe part, even a single failure wont blow up your whole plant.
My understanding is that these ruggedized pull stations are designed primarily to be electrically isolated in case there is a volatile airborne substance like fuel vapor or flour dust (yes, that is highly dangerous apparently). I believe it is supposed to be capable of withstanding a significant blunt force strike (and I suppose an explosion to some degree) without compromising the airtight seal. The fear is that sparks may ignite volatile airborne substances, especially while the pull station is operated because the contacts moving can cause a spark to occur. Also you are correct about the pull station normally being the size of the front part - on this design, the front part's normal electrical button is foregone and the button is built into the backbox instead. Normally this is attached through that big hole on the metal plate. The rugged assembly on the back is essentially a retrofit onto one of the existing conventional designs that happens to be rugged enough for such a use case.
The reason you need the key to reset pull stations is first of all not every control panel is addressable or kept up to date when the buildings are changed meaning not being able to reset the pull station without the key makes it easier to figure out which pull station was activated just by looking at it also it can help if your troubleshooting a nuisance or false alarm because you can easily see if it was someone pulling the pull station vs a fault in the wiring
13:53 if for example a cable is cut on a fire alarm pull station, or any fire alarm device, the fire alarm control panel, will not set off a full alarm. instead it will go into a trouble mode when only the control panel beeps and says that there is an open circuit
This pullstation IF on a fire alarm system would be conventional meaning that the fire alarm system only knows the zone it is in. It most probably wasn't tho. By the way the keylock is there so if someone pulls it they can't just reset it because usually a fire alarm panel (not always tho) also notifies the alarm company who notify the fire department, so if someone were to pull it they would see that someone has pulled it. Even if this wasn't used in that setting these are all manufactured in the same formfactor so they just keep the locks on all of them. Hope this helps!
Explosion proof means in electrical terms not that it will survive a blast but that if it's located in an area where you might have flammable/explosive vapors or dusts activating it will not create a spark that ignites the atmosphere, think things like chemical processing areas, fuel stations, refineries, explosive storage magazines at a quarry, grain silos etc
These kinds of pull stations are also known as intrinsically safe pull stations. The reason it was so thick was because it was attached to a backbox. The actual pull station itself is just the part with the handle, terminals and switch and can be mounted to any backbox from somewhere like a hardware store as long as its the correct size. Also there are explosion proof pull stations made of plastic such as the ones made by simplex.
the people in the area which exploded may not survive, but the people who run in from the next room over will have a fire alarm to pull. we have explosion proof light switches in the pits at work. that i dont understand, if theres an explosion, being able to turn on the lights afterward isnt a priority. its possible they are just being used for their robustness. they are incredibly simple and sturdy. im sure theyre original to the building, it was built in 1990. aside fromt the metal being a little worn on the actuating rod, they work as well as a new switch.
Fire alarm systems are 24-27 volts dc and the only thing in fire alarm that takes 120 ac is the fire alarm control panel FACP and that is only to power the panel and the 120 is kept separate from the fire alarm wiring
the main reason pull stations use a special tool or key is so people don't tamper with them. if pull stations didnt need anything to be reset, fall alarms would be much harder to track down because people would pull it and reset it quickly.
If you want more information about certain types of alarms, you really should talk to some people in the Fire Alarm Community. We aren't as bad as everyone makes us out to be.
@SFSWales that is what I tried to do. I at first had no idea about how fire alarm systems work, then attempted to ask around for further information within the Fire Alarm Community; about the inner workings of these systems. And nothing turned out good.
I think for the "keeping explosion in" part, Intrinsically safe pull stations are kinda for that in a sense. They prevent a spark that occurs when pulled, like how you can see a small spark when flipping a light switch, and that spark can.....ignite the gas in the building which is BAD. Fire alarm dude on YT has vid on Intrinsically safe vids
Some of these have a switch, that’s flips up or, the switch bridges the contacts on the NO or NC terminals, which is pretty much just a gate for electrical signals.
Why would it be run _off_ 28V to run on "wall power" if the 28V _IS_ one version of wall power when you have a system like that wired through the building? And if it's running _off_ the 28V or some other kind of wall power, then what would it be running ON?
Please excuse my ignorance in how these systems are usually installed. I was not (and still mostly now, am not) too familiar with them. For my application I just ran a power supply and used this switch to flow current to the bell and light when the switch was activated.
There is a reason they have explosion proof, pool stations it’s because normal ones make a little ark, but if there was gas in the room that would start explosion, but the explosion proof ones don’t make a ark.
Interesting. Do you think it doesn’t make an arc based on the design of the switch mechanism, or do you think it is more to do with the construction of the case?
Explosion-proof devices are generallly not waterproof, they simply have a very long physical path for any vapors or gasses to follow to reach a possible source of ignition. Probably not the best idea to use a pull station as a toy.
I have collected fire alarms for 6 years 7 if you count smoke alarms and I’ve never seen a pull station like that one
This comment makes me so happy haha. My $100 spend has been fully mentally vindicated by you.
WAIT WHAT IM PINNED AND YU REPLIED BEST TH-camR EVER
@@GridForgeMFG thank you!
@@GridForgeMFGalso very good first pull station!
@@GridForgeMFGthe max voltage for Almosr every fire alarm pull station or audible device same with visible fire alarms so like a horn strobe and pull station run on max 32 volts and all below and like 5 amps I think
Explosion proof fire alarm devices are made, so if there is frameable vapor, like gas, you can evacuate the building quickly. That yellow pull station was probably a gas leak alarm.
Places like grain elevators or other places where flammable vapors exist. It keeps the guts separated in case of arcing in the switch.
0:43 love the wall mounted ceiling mount device there on the right
That's such a cool halloween idea, those kids will remember that!
13:49 Typically, this will not set off the alarm, but it will cause a “trouble condition” on the fire alarm control panel (FACP). When there is a trouble condition, the FACP will start beeping, indicate the problem on its display, and possibly send a notification to an off site monitoring station. This is not meant to evacuate the building, but is meant to alert staff and maintenance personnel that there is an issue with the system and it is not fully functioning. The wires are supervised to be sure they are not broken. On simple, “conventional” systems this is done with a resistor across the circuit at the last device on the circuit. When the FACP no longer detects that resistance, it goes into trouble. An alarm is caused by a short circuit. On an addressable system, the FACP is constantly aware of every single device and is constantly polling every device on the system for its status. If the device stops responding, the FACP will go into trouble. When the device goes into an alarm condition, it will send back that message the next time the panel polls it (usually within a few seconds at most on modern systems).
Wow, thank you for the comment and information! As an outsider, I find these systems really interesting. It seems like a very cool problem to design something to be so safe, both in the hardware and programming.
@@GridForgeMFG These pulls can come in many colors and have different labels and stuff, if they aren't red and don't say FIRE or AGENT RELEASE, they are most definitely for something else.
@@GridForgeMFG You are welcome! I enjoy explaining things like this to people who are interested in learning. I also wanted to mention that, in most newer setups, you have something called a “class A wire loop”. Instead of the wires just going out to the devices in a single line, the wire goes in a loop so that both ends of the wire go back to the FACP. This means that, even if there is a break somewhere along the wire, the circuit is still connected on both ends. This will still cause a “trouble condition”, though. There are also many codes that regulate how these systems are wired and installed. In general, even though fire alarm usually runs at low voltage (normally 24vdc), it is treated the same as (or better than) high voltage wiring because it is a life safety system. The wire that they use for it is also a specific type that is rated to hold up better in extreme heat.
Just like your friend said, explosion proof pull stations aren't meant to be explosion proof, but instead, prevent explosions. Regular conventional pull stations, which this one is, run on 24 volts DC, and even though this isn't a lot of voltage, in hazardous conditions, you don't want a spark or anything igniting any flammable vapors, so that's what these pull stations are used for.
"Intrinsically safe" is the main keyword here. Anywhere you have a situation where there could be stuff in the air that's combustible (e g. Oil refinery, chemical plant, grain processing), the fire, building, HVAC, and electrical codes go bananas trying to prevent ANY chance of a spark causing an explosion. It's amazingly onerous to comply with as you've discovered with this relatively straightforward pull station (and for good reason given the risks to life and capital investment). Theres all sorts of intristincally safe devices and containers if you look around. Every company that works with industrial plants and automation a lot will have special models.
The Halo 3 shirt is certified drip. Great video!
Thanks nolen!!!
I think the button is held down and the button, once station is pulled, is let up. I think I've seen this exact pull station as a tornado alarm at a school video.
You are correct! I figured this out after filming (while being confused on why it was not wired how I would expect).
@@GridForgeMFG that is why these devices can be key tested without pulling the lever. Also why the Lever cant be reset without opening it. The button prevents it. I have a few t-bars myself and I've used them many times.
@@GridForgeMFGmost likely this is a normally closed switch, such as a kill switch, which are typically yellow. This would also explain why the pull station would need to be intrinsically safe.
Fire code requires fire alarm pull stations to require a tool to reset as they are meant to be latching devices. Which could either be a hex key, screwdriver, or a key.
Pull stations are rated for 24 volts not 120 volt applications. Great video and nice station
As a fire alarm collector, the keys are for as you said, to tell if it’s pulled or not. But it’s also a security and safety function. Your pull station has a toggle button. When pressed, it’s normal, when the button is pressed out, it’s activated. If the pull stations didn’t have a key, you can kinda foreshadow the outcome. Great video!
Not only is this designed so that any spark from the switch will not see off an explosive environment around it, there is a second layer to the design. The box is so sturdy that if the seals fail and the flammable/explosive vapor leaks into the box and gets set off, the box is sturdy enough to contain the explosion and prevent it from setting off the whole environment. That's the intrinsically safe part, even a single failure wont blow up your whole plant.
My understanding is that these ruggedized pull stations are designed primarily to be electrically isolated in case there is a volatile airborne substance like fuel vapor or flour dust (yes, that is highly dangerous apparently). I believe it is supposed to be capable of withstanding a significant blunt force strike (and I suppose an explosion to some degree) without compromising the airtight seal. The fear is that sparks may ignite volatile airborne substances, especially while the pull station is operated because the contacts moving can cause a spark to occur. Also you are correct about the pull station normally being the size of the front part - on this design, the front part's normal electrical button is foregone and the button is built into the backbox instead. Normally this is attached through that big hole on the metal plate. The rugged assembly on the back is essentially a retrofit onto one of the existing conventional designs that happens to be rugged enough for such a use case.
The reason you need the key to reset pull stations is first of all not every control panel is addressable or kept up to date when the buildings are changed meaning not being able to reset the pull station without the key makes it easier to figure out which pull station was activated just by looking at it also it can help if your troubleshooting a nuisance or false alarm because you can easily see if it was someone pulling the pull station vs a fault in the wiring
I love when I find a TH-cam video that answers a question I never knew I had
Great. Now I want a fire alarm pull station light switch.
6:49 that’s what she said
13:53 if for example a cable is cut on a fire alarm pull station, or any fire alarm device, the fire alarm control panel, will not set off a full alarm. instead it will go into a trouble mode when only the control panel beeps and says that there is an open circuit
Did this guy really think it was something besides a sealed container to stop a spark from setting off an explosion?
This pullstation IF on a fire alarm system would be conventional meaning that the fire alarm system only knows the zone it is in. It most probably wasn't tho. By the way the keylock is there so if someone pulls it they can't just reset it because usually a fire alarm panel (not always tho) also notifies the alarm company who notify the fire department, so if someone were to pull it they would see that someone has pulled it. Even if this wasn't used in that setting these are all manufactured in the same formfactor so they just keep the locks on all of them. Hope this helps!
Awesome! Thank you for the insight!
Explosion proof means in electrical terms not that it will survive a blast but that if it's located in an area where you might have flammable/explosive vapors or dusts activating it will not create a spark that ignites the atmosphere, think things like chemical processing areas, fuel stations, refineries, explosive storage magazines at a quarry, grain silos etc
These kinds of pull stations are also known as intrinsically safe pull stations. The reason it was so thick was because it was attached to a backbox. The actual pull station itself is just the part with the handle, terminals and switch and can be mounted to any backbox from somewhere like a hardware store as long as its the correct size. Also there are explosion proof pull stations made of plastic such as the ones made by simplex.
the people in the area which exploded may not survive, but the people who run in from the next room over will have a fire alarm to pull.
we have explosion proof light switches in the pits at work. that i dont understand, if theres an explosion, being able to turn on the lights afterward isnt a priority. its possible they are just being used for their robustness. they are incredibly simple and sturdy. im sure theyre original to the building, it was built in 1990. aside fromt the metal being a little worn on the actuating rod, they work as well as a new switch.
Oh super cool! I’ll need to look those up!
Fire alarm systems are 24-27 volts dc and the only thing in fire alarm that takes 120 ac is the fire alarm control panel FACP and that is only to power the panel and the 120 is kept separate from the fire alarm wiring
Some systems are 12v dc
the main reason pull stations use a special tool or key is so people don't tamper with them. if pull stations didnt need anything to be reset, fall alarms would be much harder to track down because people would pull it and reset it quickly.
If you want more information about certain types of alarms, you really should talk to some people in the Fire Alarm Community. We aren't as bad as everyone makes us out to be.
@SFSWales that is what I tried to do. I at first had no idea about how fire alarm systems work, then attempted to ask around for further information within the Fire Alarm Community; about the inner workings of these systems. And nothing turned out good.
@ You need to find the right community, some of the enthusiasts around this hobby are right pricks.
@@ZacharyCesario o rly? I gotta know more. What is it about the fire alarm community that's coming off as a turn off? Gatekeepers?
Man, the base box of that pull station looks like a special battery (although of course it's not one)!
This video was AWESOME.
I think for the "keeping explosion in" part, Intrinsically safe pull stations are kinda for that in a sense. They prevent a spark that occurs when pulled, like how you can see a small spark when flipping a light switch, and that spark can.....ignite the gas in the building which is BAD.
Fire alarm dude on YT has vid on Intrinsically safe vids
Very cool. I’ll check it out! What are your thoughts on the thickness of the walls? Do you think it is necessary?
@GridForgeMFG Its either just the design or for durability. I know you can also remove the backbox to just have the pull which is smaller.
Some of these have a switch, that’s flips up or, the switch bridges the contacts on the NO or NC terminals, which is pretty much just a gate for electrical signals.
It so if it is pulled in a room made for a explosion ie chemical storage it won’t blow up outside the room
"In my case I'm gonna run it off 28VDC..."
Then what would you run it *ON* (besides the 120VAC)?
Why would it be run _off_ 28V to run on "wall power" if the 28V _IS_ one version of wall power when you have a system like that wired through the building? And if it's running _off_ the 28V or some other kind of wall power, then what would it be running ON?
Please excuse my ignorance in how these systems are usually installed. I was not (and still mostly now, am not) too familiar with them.
For my application I just ran a power supply and used this switch to flow current to the bell and light when the switch was activated.
There is a reason they have explosion proof, pool stations it’s because normal ones make a little ark, but if there was gas in the room that would start explosion, but the explosion proof ones don’t make a ark.
Interesting. Do you think it doesn’t make an arc based on the design of the switch mechanism, or do you think it is more to do with the construction of the case?
yooo halo 3 merch that still fits is insane foresight
You can still find them online!
Explosion-proof devices are generallly not waterproof, they simply have a very long physical path for any vapors or gasses to follow to reach a possible source of ignition. Probably not the best idea to use a pull station as a toy.
3:03 Its so no one can tamper with it
Explosion proof means intrinsically safe. They are meant for high risk settings, and theoretically cant be a source of ignition
could be for factories where explosions are possible
A fire alarm is a system. The thing that makes the ear piercing noise and flashes is called a horn strobe not a fire alarm.
Ahh I see. Thanks for clarifying!
They are used in the same environment that you need everything else explosionproof or atex
It is, so whoever pulled it cannot just reset it
They need a key so if the pull station was pulled by some dumb person, they will not be able to reset it
The pull station is not huge it just has a back box I have not watch teh whole video yet sorry if u corrected it
Just, pull station
Ah I see. Thanks for clarifying!
@GridForgeMFG and pipe feeding that can would be rigid
W shirt