Where can I find a description of the available sound patterns (sirens)?
Sound patterns (sirens) are described in the Operation and Maintenance Documentation (O&M) and the product leaflet. Additionally, sound patterns are also included in the Certificate of Approval issued for the product by CNBOP-PIB.
What effect does the cross-section of the wires have on voltage drops?
The larger the cross-section of the wires, the lower its resistance and, consequently, the lower the voltage drops. For example, the HDGs 1x2x1.5 mm2 cable has a core resistance of R = 12.1 Ω/km, while the HTKSH 1x2x2.5 mm2 cable has a core resistance of 7.41 Ω/km. In order to calculate the voltage drop, the length of the line should be taken into account and a safety factor related to the length of the wire that may be caught in fire (increase in its resistance) should be assumed.
What effect does the attenuation of partitions have on the alarm signal level?
Obstacles such as doors affect the level of the alarm effect. For other doors, an attenuation of approximately 20 dB is acceptable, and for fire doors even approximately 30 dB. If it is not practical to use it, it is necessary to ensure the sound level in places where the siren is located behind more than one door.
What is the effect of temperature on the resistance of wires?
The resistance of the wires changes as a function of temperature. According to the ISO curve, the temperature of the PH30 cable operating in fire conditions will be 822°C after 30 minutes and its resistance will increase 4.5x! The temperature of the PH90 cable after 90 minutes will be approximately 955°C and its resistance will increase by almost 5.3x! This should be taken into account when designing the installation and appropriate safety factors should be adopted. The resistance of the cable affects voltage drops and, consequently, whether the device will operate in hazardous conditions or not. Voltage drops can be compensated by increasing the cross-section of the conductors.
How to read and what does the IP protection degree mean?
Degrees of protection provided by enclosures (IP code) is the full name of the PN-EN 60529 standard. It contains a classification of degrees of protection provided by enclosures of electrical devices with a rated voltage up to 72.5 kV.
The code consists of:
- first characteristic digit (against the ingress of foreign solids)
- second characteristic digit (against water ingress)
- additional letter (before access to hazardous parts)
- supplementary letter (supplementary information)
For example, according to EN 54-3, EN 54-23 standards, external fire alarms (type B) must provide IP33C protection. This means that the housing provides protection against:
- access to hazardous parts with a tool (2.5 mm probe)
- foreign bodies with a diameter of 2.5 mm and larger
- water spraying (at any angle up to 60° from the vertical)
How to calculate the required battery capacity for the power supply?
The required capacity K [Ah] of the battery(s) can be calculated from the formula:
K=1,25*(I1*t1+I2*t2)
Where:
K – required capacity, in ampere-hours (Ah)
t1 – support time, in hours (h)
t2 – alarm time, in hours (h)
I1 – total current consumed by the fire alarm system in the event of failure of the energy source, in amperes (A)
I2 – total current consumed by the fire alarm system when alarming, in amperes (A)
What does the IP21C and IP33C code mean?
For type A signaling devices, the manufacturer should ensure a minimum degree of 21C (in accordance with EN 60529: 1991. Degrees of protection provided by enclosures (IP code) - this standard specifies "... a system of classification of degrees of protection, marked with a code, provided by enclosures of electrical devices with rated voltage not more than 72.5 kV ... "), which is synonymous with the fact that the device itself is protected against access by foreign bodies with a diameter greater than or equal to 12.5 mm and against the harmful effects of dripping water penetrating the housing of the device. For the user himself, this is a protection against accessing hazardous parts with fingers.
On the other hand, B type devices should have a degree of protection of at least 33C. According to the standard referred to above, this means protection against the access of foreign objects with a diameter greater than or equal to 2.5 mm and against the harmful effects of sprayed water penetrating the housing of the device. The user is protected against access to hazardous parts, even when using a tool. However, it has to be said that the product should be provided with appropriate measures to restrict access to its interior to remove a part or the entire device, as well as change the mode of operation, e.g. through special tools, codes, hidden screws, seals.
What does the category (type A, type B) means?
The EN 54-23: 2010 harmonized standard introduces the division into type A (for indoor applications) and type B (for outdoor applications) VADs. This is important from the point of view of the requirements that the device must meet. In short, devices classified as type B must undergo more stringent tests, e.g. they must have a higher degree of IP protection and undergo additional tests that are not required for type A devices. All this means that they can be used both outside and inside buildings where, for example, prolonged high humidity may occur and / or be exposed to high temperatures.
Is it possible to connect a loudspeaker to the SA-K siren to deliver announcements and synchronize (alarm-message-alarm)?
Niestety nie ma takiej możliwości. Sygnalizator SA-K nie posiada mechanizmu synchronizacji, ponadto nie zalecamy łączenia urządzeń niezbadanych pod kątem współpracy (rozwiązania niecertyfikowane przez CNBOP-PIB).
Do fire alarm devices have protection against reversal of supply voltage polarity?
Tak, sygnalizatory pożarowe posiadają zabezpieczenie przed zmianą polaryzacji napięcia zasilającego.
Is it possible to turn off the sound in sounders?
Yes, it is possible. In order to switch off sound and remain an optical signal on, you should use the WSD-1 switch.
Do fire alarm devices have a built-in power supply or do they need to be powered from the control panel?
Sygnalizatory pożarowe nie posiadają wbudowanego zasilacza, konieczne jest zapewnienie zewnętrznego źródła zasilania. Do zacisków sygnalizatora powinno być doprowadzone napięcie zgodnie z dokumentacją producenta.
Is it possible to make the SA-K sounder in a 12 V version?
Yes, it is possible. If you buy such an alarm device you should be aware of the fact that the Technical Opinion and Certificate of Approval issued by the CNBOP (Scientific and Research Centre for Fire Protection) expire.
Can a fire alarm signal inform about other events?
The fire alarm signal may only be used when the desired reaction of the recipient is consistent with a fire hazard situation. In other cases, the fire alarm signal should not be used unless it is broadcast in conjunction with other information.
What are the requirements for the alarm signal pattern?
The alarm signal for the purpose of informing about fire danger should be the same in all parts of the building.
On a campus or in a place with multiple buildings, the alarm sound pattern should be the same for all buildings.
Signals from alarm devices must be different from operational signals
What sound level should the sounder provide?
The sound level should be sufficient for the acoustic alarm signal to be clearly audible above the general noise level (interfering sound level). Additionally, the signal level should not exceed 118 dB(A) in any place where people may be present.
The minimum sound level of the alarm signal should be at least 65 dB(A) or 10 dB(A) above the level of disturbing sounds lasting longer than 30 s (whichever is greater).
If the alarm signal should wake up sleeping people (rest areas), the minimum sound level at the ear level of sleeping people should be at least 75 dB(A).
Minimum levels should be achieved wherever an alarm signal should be audible.
