#From dust activation code manual#
#From dust activation code code#

In some places, particularly at college dormitories and schools, students set off fire alarms as a prank or simply because they want to (out of anger, curiosity, revenge, or to postpone a test). Opening the station causes the handle to go back to its original position, allowing the alarm to be reset from the fire alarm control panel after the station has been closed. Resetting a fire alarm pull station after it has been operated normally requires building personnel or emergency responders to open the station using a key, which often is either a hex key or a more traditional key.

This style is manufactured by many companies, most notably SimplexGrinnell.ДЄctivated Notifier NBG-12 pull station underneath a Stopper cover Perhaps the most recognizable pull station is the 'T-bar'-style pull station, so named because the handle is shaped like the letter 'T'. Other fire alarm pull stations are dual-action, and as such require the user to perform a second task before pulling down, such as lifting up or pushing in a panel on the station or shattering a glass panel with an attached hammer. Many modern fire alarm pull stations are single action and only require the user to pull down the handle to sound the alarm. Nowadays, coded pull stations are very rare and almost never seen in working fire alarm systems. Until the early 1990s, some panels were made with an extra zone to accommodate any existing coded pull stations. Coded pulls were typically used in new fire alarm systems until roughly the 1950s, and then occasionally into the 1970s.

#From dust activation code code#

Once pulled, the station would do at least four rounds of code before resetting itself. Turning it the other way and then activating the pull allows a silent test to be done in which the station's mechanical parts are checked to ensure proper function. Turning the switch one way causes the notification appliances to sound continuously (or in the case of single-stroke bells, ding once). System tests could be conducted in one of two ways: In a coded pull station, there is either a test hole on the front (usually activated with an Allen wrench) or a test switch on the inside. If there was, they would evacuate the building and call the fire department. After finding the location of the pull, they would check to see if there is a real fire. When the station was pulled, the security officers in the building would look up 5-3-1 in a master list of codes. For example, consider a pull station in the fourth floor elevator lobby of an office building with a code of 5-3-1. This code was used by building security to determine where the alarm was originating from. The teeth would push up on a contact, which would open and close a circuit, pulsing the code to the bells or horns. The gears would turn a small wheel with a specific number of teeth, which determined the coding. They had a gear mechanism that was wound up when the station was pulled, and (unlike modern pull stations) the handle did not stay down. These coded pull stations were much bigger than modern pulls and had a code wheel in them.

In the past, pull stations controlled the entire system.

#From dust activation code manual#

Manual pull stations that require two hand motions, such as lift up and pull down, or push in and pull down, have since replaced the break-glass and single-action models in many modern installations. Early strategies to cope with this problem included requiring the operator to break a pane of glass to release an internal spring-operated mechanism. Primitive manual stations, requiring only a single action or hand motion to activate, can be subject to unwanted activation by jarring or accidental contact. After operation, most fire alarm pull stations must be restored to the ready position using a special tool or key in order for the panel to be reset. In its simplest form, the user activates the alarm by pulling the handle down, which completes a circuit and locks the handle in the activated position, sending an alarm to the fire alarm control panel. A fire alarm pull station is an active fire protection device, usually wall-mounted, that, when activated, initiates an alarm on a fire alarm system.