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)
Where can I find additional information about visual alarm devices?
EN 54-23 Fire detection and fire alarm systems. Fire alarm devices. Visual alarm devices (wersja polska PN-EN 54-23:2010 Systemy sygnalizacji pożarowej — Część 23: Pożarowe urządzenia alarmowe — Sygnalizatory optyczne)
PKN-CEN/TS 54-14:2020-09 Systemy sygnalizacji pożarowej — Część 14: Wytyczne planowania, projektowania, instalowania, odbioru, eksploatacji i konserwacji
STANDARD CNBOP – PIB Nr CNBOP–PIB–0019 Ochrona Przeciwpożarowa SYGNALIZATORY OPTYCZNE
NFPA 72 National Fire Alarm and Signaling Code
COP 0001 Loss prevention code of practice. Code of practice for visual alarm devices used for fire warning. Issue 1.0
Is it possible to build a network of synchronized devices of different types?
It is possible to build a network consisting of following devices: SA-K7N, SA-K5N, SAOZ-Pk2. These signaling devices have the same synchronization mechanism which allows creating networks (synchronization).
How to understand the concept of required illuminance?
The required illuminance according to EN 54-23: 2010 is 0.4 lm / m2 on the surface perpendicular to the direction of the light emitted by the device.
How is the number of VADs estimated?
Shapes of photometric solids for signaling devices manufactured by W2 are available on the website. Depending on the version of the signaling device and the mounting height, the radius of the coverage area changes (part of the space in which the required light intensity is achieved).
For example, for the SO-P8/CC (default settings) the radius of the coverage area (R) for the suggested mounting height (h=3 m) is 4,1 m. This allows to calculate the side length (a) and the square area (Sa) for which the light intensity of 0.4 lux is provided.
click to enlarge
Considering that a = (2 x 4,1 m) / √2 ≈ 5,8 m. the square area where the required level of light intensity is assured is about 48,03m2. Based on this, it is possible to estimate the number of signaling devices needed on the x (Lx) axis and y (Ly) axis.
Example:
For example, suppose the room in question has the dimensions of x = 20 m, y = 10 m. In this case, the number of signaling devices needed on the x side will be: Lx = 20 m / 5,8 m ≈ 3,45, while the number of signaling devices on the y side will be Ly = 10 m / 6,93 m ≈ 1,72. Of course, integers should be taken for further estimates, so Lx = 4 and Ly = 2. The total number of VADs needed will finally be Lx * Ly = 4 * 2 = 8.
If the room has an irregular shape, it should be divided into smaller squares. For more detailed calculations, use * .ies files available for download from the website and applications such as DIALux or Calculux, where it is possible to take into account more variables. More information about the arrangement of VADs can be found in the American standard NFPA 72 National Fire Alarm and Signaling Code.
NOTE: The above example is used to illustrate the issue of VADs placement. It is illustrative. Under real conditions, many additional factors should be considered.
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.
When is the synchronization of VADs recommended??
EN 54-23:2010, NFPA 72 and LPCB CoP 0001 contain provisions specifying the use of synchronization of flash signals generated by VADs. When devices are installed in close proximity, their frequency / flashing pattern can lead to undesired effects - such as triggering seizures at people suffering from photosensitive epilepsy (for a detailed description of the issue, see LPCB CoP 0001). The NFPA 72 standard additionally states that synchronization should be used when at least two optical VADs are visible from one place in the building.
Certified signaling devices manufactured by W2 with a certified optical element are equipped with the synchronization function (SO-P8, SAO-P8, SGO-Pgw, SAOZ-Pk2, SGO-Pgz3).
What are the advantages of VADs with O category?
Classifying devices as category O is the most flexible approach. The following are the main advantages of the O category over the other two (C and W):
- thanks to any mounting position (ceiling, wall), the need for double inventory is eliminated (devices of categories C and W can be installed only within their category)
- no restrictions on the mounting height - for VADs classified as O only the suggested mounting height is given. In the case of a device classified as C-3-y, installation at a height higher than 3 m is not allowed. In this case, use another device, e.g. C-6-y. Suggested mounting height for the O category, e.g. 3 m, does not preclude mounting the device above this height. It should be borne in mind however, that a device with a suggested mounting height of 3 m is likely to cover a smaller area than installed e.g. at a height of 4 m
- category O devices are not subject to any restrictions - it is possible to create the largest possible coverage area in the form of any cuboid
VADs manufactured by W2 (SO-P8, SAO-P8, SGO-Pgw, SAOZ-Pk2, SGO-Pgz3) have category O.
What does the VAD coverage category mean?
In the EN 54-23: 2010 standard, apart from the division due to the working environment, a division of devices according to the coverage category has been introduced:
"C" category - ceilling mounted devices
"W" category – wall mounted devices
"O" category – open class devices
In [1], the division according to the coverage category has been characterized. For category C signaling devices, the manufacturer must specify the maximum mounting height: 3 m, 6 m or 9 m and the diameter (in meters) of the cylindrical area that is the operating range of the device installed at ceiling height, where the signaling device achieves the required light intensity. For example, the designation C-3-6 means that the VAD mounted at a height of 3 m provides the required light intensity in a cylinder with a diameter of 6 m and a height of 3 m.
For category W devices the maximum height for mounting the device on the wall (minimum 2.4 m) and the width (in meters) of the cubic area where the required luminance complies with the standard have to be specified. For example, the designation W-2.4-4 means that the VAD mounted on the wall at a height of 2.4 m will provide the required light intensity in a 2.4 x 4 x 4 m space.
The signaling devices manufactured by W2, which have an optical element certified in accordance with EN 54-23: 2010, have been classified as category O devices. This means that they can be mounted both, on ceiling and wall and the declared coverage area is represented by a photometric solid. The exact shape of the solid for devices has been made available on the W2 website.
[1] Borysewicz Jarosław, Stępień Paweł, Chołuj Łukasz, Requirements, test methods and criteria for assessing optical signaling devices (VAD). The method of measuring light distribution, BiTP Vol. 44 Issue 4, 2016, pp. 159-164
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.
Why does the housing and flash color of VADs sold in Poland have to be red?
Each acoustic or optical signaling device used in the fire alarm system must have appropriate documents confirming compliance with legal requirements.
The first legally required document is a Certificate issued for compliance with a harmonized standard. Currently, compliance with the EN 54-23: 2010 standard, which includes VADs, is issued by the CNBOP-PIB document called Certificate of Constancy of Performance. The standard defines international requirements.
Additional country requirements may exist for some product groups. In the case of sounders and VADs sold in Poland, they are included in the Annex to the Regulation of the Minister of Interior and Administration of 27 April 2010 (item 553). These devices are part of group 11, i.e. elements of warning and evacuation systems. Therefore, it is necessary to issue a Certificate of Approval for them, which confirms the fulfillment of the requirements contained in the above mentioned Regulation. Paragraph 11.5.2.1 defines the required device color and optical signal:
The VAD housing and light color should be red. The inscription "POŻAR" should be placed on the visible surface of the VAD.
It is worth adding that the current harmonized standard EN 54-23: 2010 also includes white as a possible color of the emitted light. Therefore, in countries where there are no additional local restrictions (e.g. similar to the above mentioned regulation), it is also possible to use VADs with white light as well as without the word FIRE. Devices with a certified optical element manufactured by W2 (SO-P8, SAO-P8, SAOZ-Pk2, SGO-Pgw, SGO-Pgz3) have been tested in accordance with the harmonized standard and can also be ordered with white light if necessary.
What requirements should a visual alarm device meet?
The visual alarm device should meet the requirements of the EN 54-23 standard. The fire signal should be clearly visible and different from other signals used indoors.
Visual alarm devices should be numbered and placed in such a way that they are visible from every place in the space where they are used.
Additionally, in Poland, visual alarm devices must meet the requirements contained in the regulation of the Ministry of Internal Affairs and Administration of April 27, 2010.
Where and why are VADs used?
VADs should be used wherever there is a possibility that hearing impaired people are present or hearing protectors are used. Relevant provisions regarding the use of VADs can be found in CEN/TS 54-14:2004 Fire detection and fire alarm systems - Part 14: Guidelines for planning, design, installation, commissioning, use and maintenance
"In zones where acoustic signals may be ineffective, e.g. due to the background noise being too high, hearing impaired among users, or where hearing protectors are probably worn, in addition to acoustic signals, optical signals should be used"
VADs should only be used to supplement acoustic alarm devices and should not be used alone.
“Optical fire alarm devices should only be used in addition to acoustic alarm devices and should not be used alone. Each optical fire alarm should be clearly visible and distinguishable from other optical signals used in the facility.”
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 switch off an optical signal while a sound signal is on in the fire alarm devices?
No, there is no such possibility.
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.
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.
