Two stage vs Double Action Pull station

[ElectDesigner]

Title says it all, whats the difference between a two stage and a double action pull station?

 

[sameguy]

Stage is:
single stage, pull and alarm sounds.
double stage, pull put FACP into prealarm needing, smoke or some other thing to make it sound.

Action is:
single, pull (1 move of the hand) = sound
double, lift/pull or push/pull (needs 2 moves of the hand) = sounds

 

[nhfire77]

There are two stage pulls that require a manual action (pull) and that opens a door/compartment that has a key switch that must be turned to create a full alarm.

 

[ElectDesigner]

Stage is:
single stage, pull and alarm sounds.
double stage, pull put FACP into prealarm needing, smoke or some other thing to make it sound.

Action is:
single, pull (1 move of the hand) = sound
double, lift/pull or push/pull (needs 2 moves of the hand) = sounds

This is how i understood double stage:

Pull - Prealarm state, occupant/authority given short time interval to override, when time elapses alarm sounds?

 

[nhfire77]

This is how i understood double stage:

Pull - Prealarm state, occupant/authority given short time interval to override, when time elapses alarm sounds?

You asked about a 'pull station' a physical piece of equipment. What you describe above is a two stage releasing system. The system is initiated by a pull station, a count down is initatied(stage one). The abort procedure might be initatied by pushing a button restarting the count down(stage two).

These systems vary greatly such as sameguy's example. some require the abort switch to be held in, some allow the button to be momentary, each time it's actuated, it restarts the stage two timer.

 

[gadfly56]

You asked about a 'pull station' a physical piece of equipment. What you describe above is a two stage releasing system. The system is initiated by a pull station, a count down is initatied(stage one). The abort procedure might be initatied by pushing a button restarting the count down(stage two).

These systems vary greatly such as sameguy's example. some require the abort switch to be held in, some allow the button to be momentary, each time it's actuated, it restarts the stage two timer.

Actually, he's correct. It's called "presignal". It is mentioned in 6.8.1.2 in the 2007 edition of NFPA 72, although not directly, since it deals with "fire alarm signals" of which a manually activated pull station is one example. But you only have 60 seconds to investigate, so make sure you're wearing your Keds! Here in NJ they are not allowed.

 

[nhfire77]

Makes sense, I was addressing the OP, it didn't sound like presignal. It sounded like a releasing panel set up.