Sometimes, the start of a fire is noticed by people before detectors. In such cases, the person that notices the fire should press the nearest pull station and activate the fire alarm system. Besides, in the cases where it is impossible to use any detection equipment due to extreme environmental conditions such as excessive dust, dirt, etc., activating the system is only possible with a pull station. For this reason, pull stations are one of the most important and essential elements of a fire alarm system.
In the EN 54-14 standard, it is prescribed that pull stations should be located on the escape routes, at the doors opening to the escape stairs and at the exits to the outside environment. Special attention should be paid to the position of pull stations in the areas where there are individuals with limited mobility, disabilities or in need of care. It is essential that pull stations should be clearly visible, identifiable and easily accessible. In the EN 54-11 standard, the properties and performance criteria that pull stations must fulfill are described, and the products that can provide these properties and criteria are certified by internationally-accredited organizations.
According to the EN 54-14 standard, pull stations should be located on the wall at a height between 0.90 and 1.40 m from the floor. (In the regulation dated 2015, this height was described as 1.10 - 1.30 m).
The frequency of pull stations in the field is important for the system to be activated quickly. According to the EN 54-14 standard, a pull station must be at a maximum horizontal distance of 30 m from any point. (This distance was described as 60 m in the regulation dated 2015.) This distance should be kept shorter in areas such as hospitals and nursing homes where there are people with limited mobility and slow movement.
Pressing the pull stations unconsciously or maliciously in the absence of a fire will trigger false alarms. To prevent this situation, the awareness of the occupants of the building should be increased regarding the use of pull stations, and those pressing the pull stations maliciously should be punished. As pressing the pull stations accidentally will trigger a false alarm, the buttons that could be activated with 2 movements (For example: opening the lid + pulling the lever) can be used where there is a risk of pressing the button accidentally, instead of the buttons that could be activated with single movement (For example: breaking the glass).
While pull stations are used indoors, the pull stations that fulfill the IP66/IP67 protection class can be also used outdoors in case of necessity. Besides, in the ex-proof environments, flame-proof (Ex d) or intrinsically-safe (Ex i) buttons that fulfill the suitable protection class can be used according to the explosive characteristics of the environment.
Old-type pull stations were disposable products that had to be replaced after being pressed. Today, resettable buttons are used. Resetting is usually done by using the key on the button.
As pull stations are an important and essential element for the fire alarm system, compliance with the relevant standards and regulations should be taken into consideration in the design and product selection, and it should be remembered that possible mistakes made may not be noticed in time and may result in loss of life and property.
